gis
Read this manual carefully
Warning
Read this manual carefully before starting up the water heater. Failure to
read this manual and to follow the instructions in this manual may lead to
accidents, personal injury, and damage to the appliance.
Copyright © 2007 A.O. Smith Water Products Company
All rights reserved.
Nothing from this publication may be copied, reproduced and/or published by
means of printing, photocopying or by whatsoever means, without the prior
written approval of A.O. Smith Water Products Company.
A.O. Smith Water Products Company reserves the right to modify specifications
stated in this manual.
Any brand names mentioned in this manual are registered trademarks of their
respective owners.
Trademarks
Liability
A.O. Smith Water Products Company accepts no liability for claims from third
parties arising from improper use other than that stated in this manual and in
accordance with the General Conditions registered at the Eindhoven Chamber
of Commerce.
Refer further to the General Conditions. These are available on request, free of
charge.
Although considerable care has been taken to ensure a correct and suitably
comprehensive description of all relevant components, the manual may
nonetheless contain errors and inaccuracies.
Should you detect any errors or inaccuracies in the manual, we would be
grateful if you would inform us. This helps us to further improve our
documentation.
If you have any comments or queries concerning any aspect related to the
appliance, then please do not hesitate to contact:
More information
A.O. Smith Water Products Company
PO Box 70
5500 AB Veldhoven
Netherlands
Telephone:
(free) 0870 - AOSMITH
0870 - 267 64 84
General:
Fax:
+31 40 294 25 00
+31 40 294 25 39
E-mail :
Website:
In the event of problems with connecting to the gas, electricity or water supply,
please contact your installation's supplier/installation engineer .
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Instruction manual BFM
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Table of contents
Instruction manual BFM
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Table of contents
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Instruction manual BFM
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1 Introduction
This manual describes how to install, service and use the BFM appliance. The
BFM appliance is a gas-fired sealed boiler with a fan in the air supply. The
parallel or concentric chimney connections are appliance-dependent. Possible
installation types are C13 or C33. The information in this manual applies to the:
BFM 30, BFM 50, BFM 80, BFM 100 and BFM 120.
1.1 About the appliance
The appliance has been manufactured and equipped in accordance with the
European standard for gas-fired storage water heaters for the production of
domestic hot water (EN 89). The appliances are therefore compliant with the
European Directive for Gas Appliances, and and are entitled to bear the CE
mark.
Warning
Read this manual carefully before starting up the water heater. Failure to
read the manual and to follow the printed instructions may lead to personal
injury and damage to the appliance.
Warning
If there is a gas smell:
1.2 What to do if you
smell gas
No naked flames! No smoking!
Avoid causing sparks! Do not use any electrical equipment or switch, i.e. no
telephones, plugs or bells!
Open windows and doors!
Shut off the mains gas supply valve!
Warn occupants and leave the building!
After leaving the building, alert the gas distribution company or your installation
engineer.
As the (end) user, installation engineer or service and maintenance engineer,
you must ensure that the entire installation complies, as a minimum, with the
official local:
1.3 Regulations
•
•
•
•
•
•
•
•
•
•
•
building regulations;
energy supplier's directives for existing gas installations;
directives and technical guidelines for natural gas installations;
safety requirements for low-voltage installations;
regulations governing the supply of drinking water;
regulations governing ventilation in buildings;
regulations governing the supply of air for combustion;
regulations governing the discharge of products of combustion;
requirements for installations that consume gas;
regulations governing indoor waste water disposal;
regulations imposed by fire brigade, power companies and municipality.
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1
Introduction
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Furthermore, the installation must comply with the manufacturer's instructions.
Note
Later amendments and/or additions to all regulations, requirements and
guidelines published on or prior to the moment of installing, will apply to the
installation.
A service should be carried out at least once a year, both on the water side and
on the gas side. Maintenance frequency depends, among other things, on the
water quality, the average burning time per day and the set water temperature.
1.4 Maintenance
Note
To determine the correct maintenance frequency, it is recommended to
arrange for the service and maintenance engineer to check the appliance on
both the water and gas side within three months following installation. Based on
this check, the best maintenance frequency can be determined.
Note
Regular maintenance extends the service life of the appliance.
Note
Both the end user and the service and maintenance engineer are
responsible for regular maintenance. They will need to establish clear
agreements on this.
Note
If the appliance is not regularly maintained, the warranty will become void.
The following notation is used in this manual:
1.5 Forms of notation
Note
Important information.
Caution
Ignoring this information can lead to the appliance being damaged.
Warning
Failure to carefully read this information may lead to personal injury and
serious damage to the appliance.
The three target groups for this manual are:
1.6 Target groups
•
•
•
(end) users;
installation engineers;
service and maintenance engineers.
Symbols on each page indicate the target groups for whom the information is
intended. See the table.
Target group symbols
Symbol
Target group
(End) user
Installation engineer
Service and maintenance engineer
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1.7 Overview of this
document
The table provides an overview of the contents of this document.
Contents of this document
Chapter
Target groups
Description
This chapter describes how the appliance functions.
This chapter describes the installation activity to be
completed before you actually start up the appliance.
This chapter describes how to fill the appliance.
This chapter describes how to drain the appliance.
This chapter describes the general operation of the
appliance and explains how to use the control panel.
This chapter describes the status (mode or condition) that
the appliance may have, and possible actions to take.
This chapter describes how to start the appliance running.
The general heating cycle of the appliance is also
described.
This chapter describes how to shut the appliance down for
a brief or long period of time.
This chapter is mainly intended for the installation
engineer and the service and maintenance engineer. It
describes appliance errors. A table is included stating
potential symptoms, causes and solutions. End users
may also refer to this chapter for additional information
about the appliance.
This chapter sets out the maintenance tasks to be carried
out during a service.
This chapter states the warranty terms and conditions.
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Introduction
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Instruction manual BFM
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Working principle of the appliance
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Cut-away view of the appliance
22
47
22
47
18
18
48
9
5
2
11
42
43
10
24
39
38
41
44
40
49
12
46
21
14
51
45
52
16
15
8
50
36
16
IMD-0240 R2
Legend
15. drain valve
42. high-limit thermostat
43. safety thermostat
44. frost thermostat
Only applicable numbers are
mentioned.
16. gas control
18. fan
2. hot water outlet
5. pressure switch
8. combustion chamber
9. anode
21. flame probe
45. control thermostat sensor
46. frost thermostat sensor
47. air supply
22. chimney pipe
24. insulation layer
36. bar burners/burner tray
38. safety thermostat sensor
39. high-limit thermostat sensor
40. burner control
49. air restrictor
10. tank
50 combustion chamber with
air distribution plate
11. heat exchanger
12. inspection and cleaning opening
14. cold water inlet
51. pilot burner
52. spark igniter
41. control thermostat
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In this appliance, the cold water enters the bottom of the tank through the cold
water inlet (14). The heat of combustion is conducted to the water by the
combustion chamber (50) and heat exchanger (11). The heated tap water
leaves the tank through the hot water outlet (2). Once the appliance is
completely filled with water, it will constantly be under mains water pressure.
When hot water is drawn from the appliance, it is immediately replenished with
cold water.
The air required for combustion is forced into the combustion chamber by the
fan.
The gas required for combustion flows via the gas control (16) in the manifold.
The gas control for the BFM 120 is non-standard (see box). Orifices are
mounted in the manifold. The gas is injected into the burner bars at pressure
from these orifices (36). The burner bars together form the burner tray. The
injection of gas into the burner bars also draws in the primary air from the
combustion chamber, which is required for combustion. The narrow opening in
the orifice causes the gas flow to accelerate. This in turn causes a partial
vacuum. It is this partial vacuum that draws in the air (the Venturi effect).
Ignition of the gas/air mixture takes place in two stages. First, the pilot flame is
ignited by a spark igniter. This pilot flame then ensures that the complete ignition
takes place.
The flue gases released by this combustion are led through the heat exchanger.
The heat exchanger is composed of flue tubes that contain flue baffles. These
retard the flow of the flue gases, thereby increasing the thermal efficiency of the
appliance.
The flue gases are exhausted from the appliance via the top box (46). The top
box of the BFM 100 and 120 is non-standard (see box).
An air distribution plate (50) mounted below the burner tray radiation shield also
serves as a radiation shield. Any condensation that forms is drained towards the
siphon via the air distribution plate.
The PU insulation layer (24) prevents heat loss. The inside of the tank is
enamelled to protect against corrosion. The anodes (9) offer extra protection.
2.3 The appliance's
heating cycle
The entire appliance is controlled by the burner control (40) and the control
thermostat (41) or frost thermostat (44). The control thermostat and frost
thermostat both independently measure the water temperature (T
). The
water
appliance's heating cycle is activated as soon as T
falls below the threshold
water
value (T ). The value of T depends on the selected mode of the
set
set
protection), this value is determined by the frost thermostat (threshold value =
20°C). When the appliance is in ’ON mode’, the threshold value can be set via
the control thermostat (±40°C - ±70°C).
The instant T
falls below T , the appropriate thermostat (control or frost)
set
water
will close, and the burner control will identify a heat demand. The gas control will
open, and the gas will mix with air. This mixture is ignited by the spark igniter,
and the water becomes heated. As soon as T
rises above T , the
water
set
thermostats will open once more. The heat demand is suspended, and the
burner control stops the heating cycle.
The thermostats have a certain margin both when opening and when closing.
We refer to this margin as hysteresis. The hysteresis cannot be adjusted.
2.4 Protection for the
appliance
2.4.1 Introduction
The burner control monitors the water temperature by means of thermostats,
and ensures that the combustion is safe. This takes place using:
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Working principle of the appliance
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•
•
•
2.4.2 Water temperature protection
By means of the frost, high-limit and safety thermostats, the burner control
monitors three temperatures that are important for safety. The table explains the
working principle of the thermostats with sensors.
Temperature protection
Protection
Description
Frost thermostat
When the frost thermostat sensor (46) measures a temperature of 20°C or
High-limit thermostat
When the high-limit thermostat sensor (39) measures a temperature higher
than 84°C, the high-limit thermostat will open. The heat demand is terminated
and the burner control halts the heating cycle until the high-limit thermostats
close once more. At that moment the burner control will reset the appliance and
the heating cycle will restart. The high-limit safeguard serves to prevent
overheating and/or excessive formation of scale in the appliance.
Safety thermostat
When the safety thermostat sensor (38) measures a temperature higher than
93°C, the safety thermostat will open. The heat demand is terminated and the
burner control will immediately halt the heating cycle. The burner control will go
into a lockout error state. This must be manually reset before the appliance can
resume operation.
2.4.3 Pressure switch
The pressure switch ensures the discharge of flue gases and the supply of
incoming air during the pre-purge and normal running of the appliance. The
default state of the pressure switch is open. When sufficient pressure difference
is reached, the pressure switch closes. However, in the event of a fault, the
pressure switch is tripped open, and the heating cycle is interrupted. The table
shows the trip point per appliance.
Note
The trip point of the pressure switch is not adjustable.
Pressure switch trip points
Appliance Closing pressure
difference
Opening pressure difference
< 170 Pa
BFM
30
> 200 Pa
> 270 Pa
> 255 Pa
> 610 Pa
> 220 Pa
BFM
50
< 240 Pa
BFM
80
< 225 Pa
BFM
100
< 580 Pa
BFM
120
< 190 Pa
2.4.4 Flame probe
To ensure that no gas can flow when there is no combustion, the water heater
is fitted with a flame probe (21). The burner control uses the ionisation-detecting
properties of this probe for flame detection. The burner control closes the gas
valve the instant it determines that there is a gas flow but no flame is present.
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Instruction manual BFM
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2.5 Safety of the instal-
lation
In addition to the appliance's standard built-in safety monitoring, the appliance
must also be protected by an expansion vessel, expansion valve, pressure
reducing valve, non-return valve and a T&P valve.
The use of an expansion vessel, expansion valve and/or pressure reducing
valve depends on the type of installation: unvented or vented.
2.5.1 Unvented installation
With an unvented installation, an expansion valve valve and expansion vessel
prevent the buildup of excessive pressure in the tank. This prevents damage
being caused to the enamelled coating (in the appliance) or to the tank. A non-
return valve prevents excessive pressure buildup in the water supply system.
This valve also prevents water from flowing backwards from the tank into the
cold water supply system. The pressure reducing valve protects the installation
against an excessively high water supply pressure (> 8 bar). These components
2.5.2 Vented installation
With a vented installation, excess pressure is taken up by the open cold water
head tank. The height of the head tank determines the working pressure in the
water heater, which may not exceed 8 bar. The installation must also be fitted
with a vent pipe from the hot water pipe, that opens into the cold water tank.
Ideally, the vent pipe should discharge into a separate tundish/drain or
otherwise to the open cold water head tank. The water heater should also be
2.5.3 T&P valve
A T&P valve is only mandatory in an unvented installation. However, A.O. Smith
also recommends the use of a T&P valve in vented installations.
A T&P (Temperature and Pressure Relief) valve monitors the pressure in the
tank and the water temperature at the top of the tank. If the pressure in the tank
becomes excessive (> 10 bar) or the water temperature is too high (> 97°C), the
valve will open. The hot water can now flow out of the tank. Because the
appliance is under water supply pressure, cold water will automatically flow into
the tank. The valve remains open until the unsafe situation has been rectified.
The appliance is fitted standard with a connecting point for a T&P
Instruction manual BFM
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Working principle of the appliance
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16
Instruction manual BFM
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3 Installation
Warning
Installation work should be carried out by an approved installation engineer
in compliance with the general and local regulations imposed by the gas, water
and power supply companies and the fire service.
The appliance may only be installed in a room that complies with the
requirements stated in national and local ventilation
This chapter describes the installation activities to be carried out before the
3.1 Introduction
•
•
•
•
•
•
•
•
•
For a possible conversion to a different gas category, see
To avoid damaging the appliance, remove the packaging carefully.
We recommend unpacking the appliance at or near its intended location.
3.2 Packaging
Caution
The appliance may only be manoeuvred in an upright position. Take care
that the appliance is not damaged after unpacking.
The appliance has a sealed combustion chamber, and obtains its air supply
independently of the boiler room. There are therefore no additional ventilation
requirements.
3.3 Ambient conditions
Possible installation types are C13 and C33.
3.3.1 Air humidity and ambient temperature
The boiler room must be frost-free, or be protected against frost. The table
shows the environmental conditions that must be adhered to for correct
functioning of the electronics present in the appliance to be guaranteed.
Air humidity and ambient temperature specifications
Air humidity and ambient temperature
Air humidity
max. 93% RV at +25°C
Functional: 0 < T < 60°C
Ambient temperature
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Installation
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3.3.2 Maximum floor load
Allow for the appliance's weight with respect to the maximum floor load; refer to
the table.
Weight of the appliance filled with water
BFM 30
539 kg
BFM 50
543 kg
BFM 80
548 kg
BFM 100
573 kg
BFM 120
573 kg
3.3.3 Water composition
The appliance is intended for heating drinking water. The drinking water must
comply with the regulations governing drinking water for human consumption.
The table gives an overview of the specifications.
Water specifications
Water composition
Hardness
> 1.00 mmol/l:
(alkaline earth ions)
•
•
•
German hardness> 5.6° dH
French hardness > 10.0° fH
English hardness > 7.0° eH
Conductivity
> 125 µS/cm
Acidity (pH value)
7.0 < pH value < 9.5
Note
If the water specifications deviate from those stated in the table, then the
3.3.4 Working clearances
For access to the appliance, it is recommended that the following clearances
are observed (see figure):
•
•
•
AA: around the appliance's control column and cleaning openings: 100cm.
BB: all sides of the appliance: 50cm.
Above the appliance (room to replace the anodes):
-
-
100cm if using fixed anodes, or
50cm if using flexible anodes.
If the available clearance is less than 100cm, flexible magnesium anodes
may be ordered.
Note
When installing the appliance, be aware that any leakage from the tank
and/or connections can cause damage to the immediate environment or floors
below the level of the boiler room. If this is the case, the appliance should be
installed above a wastewater drain or in a suitable metal leak tray.
The leak tray must have an appropriate wastewater drain and must be at least
5cm deep with a length and width at least 5cm greater than the diameter of the
appliance.
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Installation
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3.4.1 Dimensions of the appliance
Plan and elevation of the appliance
1
2
F
F
C
C
L
Hy
E
E
G/L
G
10º
4/6
10º
4/6
6
6
45º
45º
37º
37º
D
2
5
A
B
6
6
N
S
1
3
4
P
P
K
M
R
IMD-0057 R5
Replacement of burner pressure regulator or blank plate BFM30-50-80-100
(2) = BFM 100, 120
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Instruction manual BFM
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Dimensions (all measurements in mm unless otherwise indicated)
Dimens Description
ion
BFM30
BFM50
BFM80
BFM100 BFM120
A
B
C
D
E
F
Total height
2000
1800
580
710
1000
755
80
2000
1800
580
710
1000
755
100
-
2020
1820
580
710
1000
755
130
-
2020
1820
580
710
1000
755
130
235
600
130
590
1655
760
540
2020
1820
580
710
1000
755
130
235
760
130
590
1655
760
540
Height of top of appliance
Position on pallet
Appliance diameter
Depth
Width
G
Hy
K
L
Diameter of chimney flue
y-position air supply
Height of gas connection
Diameter of Air supply
Height of cold water supply
Height of hot water outlet
Height of cleaning opening
Height of drain valve connection
Height of T&P valve connection
-
600
125
600
1640
770
550
600
150
600
1640
770
550
600
200
590
1655
760
540
M
N
P
R
S
1
1600
1600
1600
1600
1600
1
1
1
1
1
Cold water supply connection (external) R1 /
R1 /
R1 /
R1 /
R1 /
2
2
2
2
2
1
1
1
1
1
2
Hot water outlet connection (internal)
Gas control connection (internal)
Drain valve connection (internal)
T&P valve connection (internal)
Rp1 /
Rp1 /
Rp1 /
Rp1 /
Rp1 /
Rp1
2
2
2
2
2
2
3
3
3
3
3
Rp /
Rp /
Rp /
Rp /
4
4
4
4
1
1
1
1
1
4
Rp1 /
Rp1 /
Rp1 /
Rp1 /
Rp1 /
2
2
2
2
2
2
2
1
1
1
5
1 - 11.5
NPT
1 - 11.5
NPT
Rp1 /
Rp1 /
Rp1 /
6
Cleaning/inspection opening
Ø 100
Ø 100
Ø 100
Ø 100
Ø 100
3.4.2 General and electrical specifications
General and electrical specifications
DESCRIPTION
Unit
BFM
30
BFM
50
BFM
80
BFM
100
BFM
120
Volume
litres
309
8
298
8
253
8
253
8
253
8
Maximum operating pressure
Empty weight
bar
kg
230
37
36
2
245
22
42
2
295
12
54
4
320
9
320
8
o
Heating-up time ΔT = 45 C
minutes
Diameter of air restrictor
mm
48
4
64
4
Number of anodes
-
Number of bar burners/orifices
Number of flue tubes/flue baffles
Electrical power consumption
-
3
5
7
7
7
-
5
7
16
100
230
16
275
230
16
300
230
W
100
230
100
230
Supply voltage
volts
(-15% +10% VAC)
Mains frequency
IP class
Hz (± 1Hz) 50
20
50
20
50
20
50
20
50
20
-
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Installation
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3.4.3 Gas data
Gas data
Description
Unit
BFM
30
BFM
50
BFM
80
BFM
100
BFM
120
Gas category: 30 through 100 II
Natural gas G20 - 20 mbar
Orifice diameter
, 120: II
2H3P
2H3+
mm
2.60
2.50
2.70
3.20
3.30
Diameter of pilot flame orifice
mm
0.56/0.41 0.56/0.41 0.56/0.41 0.56/0.41 0.56/0.41
(1) = Blank plate
1 or 2
2
2
2
2
2
(2) = Burner pressure regulator
Nominal load (upper value)
Nominal output
kW
32.2
26.4
20
52.2
42.3
20
83.3
67.5
20
113.3
90.8
20
127.7
102.4
20
kW
Supply pressure
mbar
mbar
(†)
Burner pressure
12.5
3.1
12.9
5.0
12.9
7.9
12.5
10.8
14.0
12.2
(*)
3
Gas consumption
m /h
LP gas data
G30 - 30 mbar (butane)
Orifice diameter
mm
1.45
0.25
1
1.40
0.25
1
1.50
0.25
1
1.95
0.25
1
n.a.
Diameter of pilot flame orifice
mm
(1) = Blank plate
1 or 2
(2) = Burner pressure regulator
Nominal load (upper value)
Nominal output
kW
31.4
26.4
30
49.9
41.4
30
81.3
67.5
30
110.5
90.8
30
kW
Supply pressure
mbar
mbar
kg/h
(†)
Burner pressure
-
-
-
-
(*)
Gas consumption
2.3
3.6
5.9
8.0
G31 - 37mbar (propane)
Orifice diameter
mm
1.45
0.25
1
1.40
0.25
1
1.50
0.25
1
1.95
0.25
1
2.30
0.25
2
Diameter of pilot flame orifice
mm
(1) = Blank plate
1 or 2
(2) = Burner pressure regulator
Nominal load (upper value)
Nominal output
kW
kW
mbar
-
30.4
25.5
37
47.8
39.6
37
77.2
63.9
37
110.9
90.8
37
125.0
102.4
37
Supply pressure
(†)
Burner pressure
-
-
-
--
22.0
8.9
(*)
Gas consumption
kg/h
2.2
3.4
5.5
7.9
(*) Based on 1013.25 mbar and 15 °C.
(†) If using a blank plate instead of a burner pressure regulator, it is assumed that the burner pressure is equal to
the supply pressure. In practice, however, the burner pressure will be lower.
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Instruction manual BFM
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3.5 Installation diagram
3.5.1 Installation
This figure shows the installation diagram. This diagram is used in the sections
in which the actual connection process is described.
Installation diagram
Legend
UNVENTED
Only applicable numbers are
mentioned.
14
14
14
1. pressure reducing valve
(mandatory)
3. T&P valve (mandatory)
12
4. stop valve (recommended)
5. non-return valve (mandatory)
6. circulation pump (optional)
B
11
3
4
7. top to bottom circulation pump
(optional)
4
6
5
7
5
9. drain valve
4
16
4
10. manual gas valve (mandatory)
11. service stop valve (mandatory)
D
5
10
1
4
A
C
12. temperature gauge
(recommended)
15
9
14. hot water draw-off points
13
15. expansion valve (mandatory)
16. expansion vessel (mandatory)
17. 3-way aeration valve
(recommended)
VENTED
H
18. water tank
19
A
E
19. float valve
4
A. cold water supply
B. hot water supply
C. circulation pipe
D. gas supply
18
17
12
B
E. overflow pipe
H. overflow pipe
11
3
4
7
14
5
4
C
4
6
5
4
C
4
9
D
10
13
IMD-0467 R0
Instruction manual BFM
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3
Installation
Warning
is
3.6 Water connections,
Vented
The installation should be carried out by an authorised installation engineer,
3.6.1 Cold water side
1. Fit an approved stop valve (4) on the cold water side between the cold water
head tank (18) and the appliance, as required by
3.6.2 Recirculation pipe
You can install a top to bottom circulation pump to prevent water stacking in the
boiler.
1. Optional: depending on the draw-off pattern, fit a recirculation pipe (Ø 22
mm), a stop valve (11) and a top to bottom circulation pump (7).
2. Fit a non-return valve (5).
3. Fit a stop valve (11).
3.6.3 Hot water side
Note
Insulating long hot water pipes prevents unnecessary energy loss.
1. Fit the T&P valve (3).
2. Optional: fit a temperature gauge (12) so you can check the temperature of
the tap water.
3. Fit a stop valve (4) in the hot water outlet pipe, for use when servicing.
4. If a circulation pipe is required, continue further by installing the circulation
3.6.4 Drain valve
1. Fit the standard drain valve (9) supplied with the appliance.
If not, fit the blind threaded plug and gasket (C) supplied with the drain valve,
as shown in the figure.
C
IMD-0122 R1
24
Instruction manual BFM
is
3.6.5 Circulation pipe
If an immediate flow of hot water is required at draw-off points, a circulation
pump can be installed. This improves comfort and reduces water wastage.
1. Fit a circulation pump (6) of the correct capacity for the length and resistance
of the circulation system.
2. Fit a non-return valve (5) behind the circulation pump to guarantee the
direction of circulation.
3. Fit two stop valves for service purposes (4).
4. Connect the circulation pipe to the T-piece at the drain valve (9) as shown in
Warning
3.7 Water connections,
Unvented
The installation should be carried out by an authorised installation engineer,
3.7.1 Cold water side
1. Fit an approved stop valve (4) on the cold water side as required by
2. The maximum working pressure of the appliance is 8 bar. Because the
pressure in the water pipe at times can exceed 8 bar, you must fit an
approved pressure-reducing valve (1).
3. Fit a non-return valve (5) and an expansion vessel (16).
4. Fit an expansion valve (15) and connect the overflow side to an open
wastewater pipe.
3.7.2 Recirculation pipe
You can install a top to bottom circulation pump to prevent water stacking in the
boiler.
1. Optional: depending on the draw-off pattern, fit a recirculation pipe (Ø 22
mm), a stop valve (11) and a top to bottom circulation pump (7).
2. Fit a non-return valve (5).
3. Fit a stop valve (11).
3.7.3 Hot water side
Note
Insulating long hot water pipes will prevent unnecessary energy loss.
1. Optional: fit a temperature gauge (12) so you can check the temperature of
the tap water.
2. Fit the T&P valve (3).
3. Fit a stop valve (11) in the hot water outlet pipe for servicing.
3.7.4 Drain valve
1. Fit the standard drain valve (9) supplied with the appliance.
If not, fit the blind threaded plug and gasket (C) supplied with the drain valve,
as shown in the figure.
Instruction manual BFM
25
3
Installation
is
C
IMD-0122 R1
3.7.5 Circulation pipe
If an immediate flow of hot water is required at draw-off points, a circulation
pump can be installed. This improves comfort and reduces water wastage.
1. Fit a circulation pump (6) of the correct capacity for the length and resistance
of the circulation system.
2. Fit a non-return valve (5) behind the circulation pump to guarantee the
direction of circulation.
3. Fit two stop valves for service purposes (4).
4. Connect the circulation pipe to the T-piece at the drain valve (9) as shown in
Warning
3.8 Gas connection
The installation should be carried out by an authorised installation engineer,
Caution
Make sure that the diameter and length of the gas supply pipe are large
enough to supply sufficient capacity to the appliance.
1. Fit a manual gas valve (10) in the gas supply pipe.
2. Blow the gas pipe clean before use.
3. Close the manual gas valve.
4. Fit the gas supply pipe to the gas control.
Warning
After fitting, check for leaks.
26
Instruction manual BFM
is
3.9 Air supply and flue
3.9.1 Introduction
Warning
The installation should be carried out by an authorised installation engineer,
The BFM 30, 50 and 80 differ from the BFM 100 and 120 in how the air supply
and chimney flue are connected.
3.9.2 Installing chimney flue components for BFM 30, 50, 80
The BFM-appliances are approved for installation types C13 and C33. The
instruction manual describes these types. For a more detailed explanation,
please contact your supplier or the manufacturer.
Note
We prescribe the use of a concentric roof or wall flue terminal, exclusively of
a type approved for the appliance.
You must fulfil the following requirements:
•
•
•
The maximum permissible length of chimney pipe (A+B+C) is 7 metres.
The maximum permissible number of 45° or 90° bends is 2.
If you are using a horizontal pipe, you must mount it with a minimum run-off
of 5 mm per running metre of pipe towards the appliance!
•
Make sure that the chimney discharges into an area approved for this type
of appliance.
Instruction manual BFM
27
3
Installation
is
3.9.3 Concentric wall flue terminal BFM 30-50-80
Wall flue terminal
B
.
A
IMD 0060 R2
3.9.4 C13 concentric wall flue terminal specifications (BFM 30, 50, 80)
C13 Concentric wall flue terminal specifications
Subject
Wall flue terminal set:
Description
1
Art. No.
BFM 30
BFM 50
BFM 80
0302 515
0302 504
0302 326
1
1
•
1x Wall flue terminal (incl. wall flange
& clamping ring)
•
•
1x Pipe 500 mm
1x Bend 90°
Construction
Manufacturer
Type
Concentric
Muelink & Grol
M2000 MDV SE WL
Concentric
Pipe material
Construction
Chimney flue
Air supply
Thick-walled aluminium with lip ring seal
Thin-walled galvanised sheet steel
Pipe diameters
Chimney flue
BFM 30
BFM 50
BFM 80
Ø 80 mm
Ø 100 mm
Ø 130 mm
Air supply
BFM 30
BFM 50
BFM 80
Ø 125 mm
Ø 150 mm
Ø 200 mm
(1) No other wall flue terminal is permitted. Order the wall flue terminal set from manufacturer or trade supplier,
stating the article number.
28
Instruction manual BFM
3
Installation
is
3.9.6 C33 concentric roof flue terminal specifications (BFM 30, 50, 80)
C33 concentric roof flue terminal specifications
Subject
Roof flue terminal set:
Description
1
Art. No.
BFM 30
BFM 50
BFM 80
0302 518
0302 507
0302 327
1
1
•
1x Roof flue terminal (incl.
clamping ring)
•
•
1x pipe 1000 mm
Construction
Manufacturer
Type
Concentric
1x mounting flange
Muelink & Grol
M2000 DDV SE HR/VR
Concentric
Pipe material
Construction
Chimney flue
Air supply
Thick-walled aluminium with lip ring seal
Thin-walled galvanised sheet steel
Pipe diameters
Chimney flue
BFM 30
BFM 50
BFM
Ø 80 mm
Ø 100 mm
Ø 130 mm
80
Air supply
BFM 30
BFM 50
BFM
Ø 125mm
Ø 150 mm
Ø 200 mm
80
(1) No other roof flue terminal is permitted. Order the roof flue terminal set from manufacturer or trade supplier,
stating the article number.
3.9.7 Installing chimney flue components for BFM 100, 120
The air supply duct (1) and chimney flue (2) for the BFM 100 and 120 emerge
separately from the top box. They must be connected to the concentric wall flue
terminal or roof flue terminal by means of a transition piece.
Parallel connection BFM 100, 120
Legend
1. Air supply
1
2. chimney flue
2
IMD-0252 R1
30
Instruction manual BFM
is
A.O. Smith prescribes the use of a concentric roof or wall flue terminal,
exclusively of a type approved for the appliance. Use of an incorrect roof or wall
flue terminal can cause the installation to malfunction.
You must also fulfil the following requirements:
•
•
•
The maximum permissible length of chimney pipe (A+B+C) is 7 metres.
The maximum permissible number of 45° or 90° bends is 2.
If you are using a horizontal pipe, you must mount it with a minimum run-off
of 5 mm per running metre of pipe towards the appliance!
•
The transition piece to convert the air supply and chimney flue from parallel
to concentric must be installed immediately before the wall or roof flue
terminal.
•
•
The intake duct of the air supply must be approximately the same as the
chimney flue.
Make sure that the chimney flue discharges into an area approved for this
type of appliance.
See the figures. Wall flue terminal (3.9.8 "Concentric wall flue terminal BFM100,
120") for examples of installation.
3.9.8 Concentric wall flue terminal BFM100, 120
Wall flue terminal
.
B
A
IMD-0226 R1
Instruction manual BFM
31
3
Installation
is
3.9.9 C13 concentric wall flue terminal specifications (BFM 100, 120)
C13 Concentric wall flue terminal specifications
Subject
Wall flue terminal set:
Description
1
Art. No.
0306 774
•
1x Wall flue terminal (incl. wall flange
& clamping ring)
Construction
Manufacturer
Type
Concentric
Muelink & Grol
M2000 MDV SCC
•
•
•
•
1x Clamping ring
1x Transition piece
2x Pipe 500 mm
2x Bend 90°
Pipe material
Construction
Chimney flue
Air supply
Parallel
Thick-walled aluminium with lip ring seal
Thick-walled aluminium with lip ring seal
Ø 130 mm
Pipe diameters
Chimney flue
Air supply
Ø 130 mm
(1) No other wall flue terminal is permitted. Order the wall flue terminal set from manufacturer or trade supplier,
stating the article number.
32
Instruction manual BFM
3
Installation
is
3.9.11 C33 concentric roof flue terminal specifications (BFM 100, 120)
C33 concentric roof flue terminal specifications
Subject
Roof flue terminal set:
Description
1
Art. No.
0306 773
•
1x Wall flue terminal (incl. clamping
ring)
Construction
Manufacturer
Type
Concentric
Muelink & Grol
M2000 DDV SE
•
•
1x Pipe 1000 mm
1x Mounting flange
Pipe material
Construction
Chimney flue
Air supply
Parallel
Thick-walled aluminium with lip ring seal
Thick-walled aluminium with lip ring seal
Ø 130 mm
Pipe diameters
Chimney flue
Air supply
Ø 130mm
(1) No other roof flue terminal is permitted. Order the roof flue terminal set from manufacturer or trade supplier,
stating the article number.
Warning
3.10 Electrical
connection
The installation should be carried out by an authorised installation engineer,
This paragraph describes the electrical connections.
The figure shows a view of the electrical connector block, and the table shows
the appropriate connections.
Connector block
Legend
A. screws
B. protective cap
C. connector block
B
A
C
10
1
IMD-0243 R1
34
Instruction manual BFM
is
In preparation you should first remove the two plastic covers and the
protective cap of the electrical section.
1. Undo the screws of the plastic covers.
2. Carefully remove the covers from the appliance.
The electrical section is now visible.
3. Loosen the 2 screws (A) of the electrical section, and remove the protective
cover (B) from the electrical section.
The connector block (C) is now visible.
Note
Refer to the table for connections 1 through 10.
component connections.
Electrical connector block
Mains power
Fan
N
Alarm Off
N
1
L1
2
L
5
S1
7
S2
8
S3
9
S4
10
3
4
6
3.10.1 Connecting the mains power
The appliance is supplied without a power cable and isolator.
Note
In order to receive electrical power, the appliance has to be connected to the
mains power by means of a permanent electrical connection. A double-pole
isolator with a contact gap of at least 3 mm must be fitted between this
permanent connection and the appliance. The power cable must have cores of
2
at least 3 x 1.0 mm .
Warning
Leave the appliance isolated until you are ready to start it up.
1. Feed the power cable through the metric strain relief to the top side of the
control column.
2. Connect the earth ( ), live (L ) and neutral (N) of the power cable to
1
terminals 1 through 3 in the connector block as stated in the table.
3. Turn the strain relief tight to clamp the lead.
4. If you do not need to make any more connections, fit the protective cover
onto the control column.
5. Connect the power cable to the isolator.
Warning
>Leave the appliance electrically isolated until you are ready to start it up.
Instruction manual BFM
35
3
Installation
Note
is
3.11 Checking the supply
pressure and burner
pressure
Before starting the appliance and/or checking the supply pressure and
Caution
Before starting up for the first time or after conversion, you must always
check the supply pressure and burner pressure.
Note
The easiest way to check the gas pressures is by using two pressure
gauges. This procedure assumes that these two gauges are available.
If the appliance is to be run on a different gas category than the factory preset
gas category (see type plate) then you must first convert (4 "Conversion to a
different gas category") the appliance.
Gas control for BFM 30 through 100
Legend
1
1. burner pressure regulator
2. burner pressure regulator cap
3
2
3. burner pressure regulator
adjustment screw
4. gas control connector
5. blank plate
6
7
6. supply pressure test nipple
7. gas control
8. manifold test nipple
8
4
5
IMD-0256 R1
36
Instruction manual BFM
is
Gas control for BFM 120
Legend
6
1. burner pressure regulator
3. burner pressure regulator
adjustment screw
6. supply pressure test nipple
7. gas control
7
8. manifold test nipple
3
8
1
IMD-0257 R1
2. There are two test nipples on the gas control. Test nipple (6) is used to check
the supply pressure. The other test nipple on the gas control is not used. The
manifold test nipple (8) is used to measure the burner pressure.
Sealing screws are located inside the test nipples. Loosen both sealing
screws by a few turns. Do not completely loosen them; they can be difficult
to re-tighten.
3. Connect a pressure gauge to the manifold test nipple (8).
4. Open the gas supply and bleed the air from the mains gas supply via test
nipple (6).
5. Connect a pressure gauge to the manifold test nipple (6) when gas starts to
flow from this nipple.
6. Switch on the power to the appliance using the isolator on the appliance.
7. Set the control thermostat to the maximum temperature and start the
appliance running by setting the ON/OFF switch to position I.
8. The heating cycle will start, and after a short time the burner tray will ignite.
9. After the burner tray has ignited, wait approximately 1 minute before reading
the dynamic pressures.
10. Use the pressure gauge to read the supply pressure at test nipple (6). Refer
Note
Consult the mains gas supply company if the supply pressure is not correct.
Instruction manual BFM
37
3
Installation
is
11. Use the pressure gauge to read the burner pressure at nipple (8). Refer to
Note
If the burner pressure is incorrect and the appliance is fitted with a blank
plate or high-low control, then you cannot adjust the pressure. In this case,
consult your installation engineer or supplier. If the appliance is indeed fitted
with a burner pressure regulator, then you can adjust the pressure.
12. BFM 30, 50, 80, 100
13. Remove the cap (2) from the burner pressure regulator.
14. Depending on the correction required, correct the burner pressure by turning
adjustment screw (3):
-
-
Adjustment screw anticlockwise: burner pressure decreases.
Adjustment screw clockwise: burner pressure increases.
15. BFM 120
16. Remove the cap (2) from the burner pressure regulator.
17. Depending on the correction required, correct the burner pressure by turning
adjustment screw (3) (PG) using the Allen key supplied with the appliance:
-
-
Adjustment screw anticlockwise: burner pressure decreases.
Adjustment screw clockwise: burner pressure increases.
Warning
Adjustment screw (Ps) adjusts the starting pressure. This need not, and
must never be adjusted from the factory preset.
18. Check the burner pressure against the value given in the gas
19. If the pressure reading is not correct, repeat the burner pressure adjustment
until the correct pressure is obtained.
20. Shut down the appliance by setting the 0/1 switch to position 0.
21. Shut off the gas supply.
22. Disconnect the two pressure gauges and re-tighten the sealing screws in the
test nipples.
Note
Before starting-up the appliance, take time to fill in the warranty card
supplied with the appliance. This enables us to guarantee the quality of our
systems and further enhance our warranty procedure.
Please return this card as soon as possible. Your customer will then receive a
warranty certificate with our warranty conditions
38
Instruction manual BFM
is
4 Conversion to a
different gas category
Caution
The conversion may only by carried out by an authorised installation
engineer.
If the appliance must operate on a family of gases (LP gas or natural gas) or
other gas category than that for which the appliance has been set at the
factory, the appliance will have be adapted using a special conversion kit.
Caution
You must check the supply pressure and burner pressure once the
conversion is complete.
the power supply.
4.1 Conversion
2. Shut off the gas supply.
flame orifice for the intended gas category is different from the one that is
Note
The current gas category is stated on the type plate.
orifice for the intended gas category is different from the one that is currently
a blank plate or burner pressure regulator is required for the intended gas
category. If this is different than for the current gas category,
pressure and burner pressure for the intended gas category correspond with
those for the current gas category, and adjust (3.11 "Checking the supply
pressure and burner pressure") these if necessary.
Instruction manual BFM
39
4
Conversion to a different gas category
is
Gas control assembly removed
4.2 Orifice replacement
1. strain relief
2. spark electrode lead
3. flame probe lead
4. burner control
5. gas control connector(s)
6. gas control
7
6
4
5
7. gas coupling
8. burner tray
1
7
6
5
5
8
2
3
IMD-0254 R1
1. Remove the protective cover from the control column:
undo the 4 screws and remove the protective cover by lifting it. The electrical
section will now be exposed.
2. Remove the strain relief (1) and disconnect the leads of the spark electrode
(2 = red) and the flame probe (3 = black) from the burner control (4).
3. Unscrew the connector(s) (5) of the gas control (6).
4. Remove the gas coupling (7) of the gas control.
5. Remove the ten screws that fasten the burner tray (8).
6. Withdraw the burner tray from the appliance.
Note
When exchanging the pilot flame orifice and/or main orifices: Lay the burner
tray on its side and approach it from the underside.
to be replaced:
a. Remove the spark electrode (1) from its retaining clip. This way you will
gain space to remove the pilot flame orifice.
b. Turn the flame probe (2) and remove it from its bracket to gain space.
c. Remove the bracket of the pilot flame orifice (3)
d. Replace the current pilot flame orifice (4) with a pilot flame orifice of the
correct diameter from the conversion set.
e. Check the pilot flame orifice. The orifice diameter is stamped on the
orifice itself.
f. Re-fit the bracket, the flame probe and the spark electrode.
40
Instruction manual BFM
is
need to be replaced:
a. Remove the main orifices (5).
b. Fit the main orifices from the conversion set. Check the required orifice
orifice diameter is stamped on the orifice itself.
9. If necessary, replace the blank plate or burner pressure regulator.
10. Re-fit the burner tray and fasten it using the screws.
11. Fit the gas coupling to the gas control and firmly tighten the connector(s) of
the gas control.
12. Reconnect the leads of the spark electrode and flame probe to the burner
control and fasten them in the strain relief.
13. Connect the gas supply..
14. Re-fit the protective cover.
Note
connection of the electrical components.
Referring to the gas table, determine whether the gas control needs to be fitted
with a blank plate or burner pressure regulator. If necessary, replace them as
follows:
4.3 Replacement of
burner pressure
regulator or blank
plate BFM30-50-80-
100
2. Remove the burner pressure regulator or blank plate from the appliance.
3. Fit the burner pressure regulator or blank plate from the conversion set.
Note
Once you have completed the replacement of the components, you must
check the supply pressure and burner pressure to match the intended gas
Instruction manual BFM
41
4
Conversion to a different gas category
is
42
Instruction manual BFM
gis
5 Filling
Installation diagram
Legend
UNVENTED
Only applicable numbers are
mentioned.
14
14
14
1. pressure reducing valve
(mandatory)
3. T&P valve (mandatory)
12
4. stop valve (recommended)
5. non-return valve (mandatory)
6. circulation pump (optional)
B
11
3
4
7. top to bottom circulation pump
(optional)
4
6
5
7
5
9. drain valve
4
16
4
10. manual gas valve (mandatory)
11. service stop valve (mandatory)
D
5
10
1
4
A
C
12. temperature gauge
(recommended)
15
9
14. hot water draw-off points
13
15. expansion valve (mandatory)
16. expansion vessel (mandatory)
17. 3-way aeration valve
(recommended)
VENTED
H
18. water tank
19
A
E
19. float valve
4
A. cold water supply
B. hot water supply
C. circulation pipe
D. gas supply
18
17
12
B
E. overflow pipe
H. overflow pipe
11
3
4
7
14
5
4
C
4
6
5
4
C
4
9
D
10
13
IMD-0467 R0
Instruction manual BFM
43
5
Filling
gis
To fill the appliance, proceed as follows:
5.1 Filling unvented
installations
1. Open the stop valve (11) in the hot water pipe and, if present, the stop valves
(4) for the circulation pump (6).
2. Close the drain valve (9).
3. Open the nearest hot water draw-off point (14).
4. Open the stop valve (4) on the cold water side (A) so that cold water flows
into the appliance.
5. Completely fill the appliance. When a full water jet flows from the nearest
draw-off point, the appliance is full.
6. Bleed the entire installation of air, for example by opening all draw-off points.
7. The appliance is now under water supply pressure. There should be no
water coming out of the expansion valve (15), nor the T&P valve (3). If this
does happen, the cause might be:
-
The water supply pressure is greater than the specified 8 bar.
Rectify this by fitting a pressure reducing valve (1).
-
The expansion valve in the protected cold supply setup is defective or
incorrectly fitted.
To fill the appliance, proceed as follows:
5.2 Filling vented instal-
lations
1. Open the stop valve (11) in the hot water pipe and, if present, the stop valves
(4) for the circulation pump (6).
2. Close the drain valve (9).
3. Open the nearest hot water draw-off point (14).
4. Open the stop valve (4) on the cold water side (A) so that cold water flows
into the appliance.
5. Completely fill the appliance. When a full water jet flows from the nearest
draw-off point, the appliance is full.
6. Bleed the entire installation of air, for example by opening all draw-off points.
7. The appliance is now under water supply pressure. There should be no
water coming out of the T&P valve (3). If this does happen, the T&P valve
might be defective or incorrectly fitted.
44
Instruction manual BFM
gis
6 Draining
Installation diagram
Legend
UNVENTED
Only applicable numbers are
mentioned.
14
14
14
1. pressure reducing valve
(mandatory)
3. T&P valve (mandatory)
12
4. stop valve (recommended)
5. non-return valve (mandatory)
6. circulation pump (optional)
B
11
3
4
7. top to bottom circulation pump
(optional)
4
6
5
7
5
9. drain valve
4
16
4
10. manual gas valve (mandatory)
11. service stop valve (mandatory)
D
5
10
1
4
A
C
12. temperature gauge
(recommended)
15
9
14. hot water draw-off points
13
15. expansion valve (mandatory)
16. expansion vessel (mandatory)
17. 3-way aeration valve
(recommended)
VENTED
H
18. water tank
19
A
E
19. float valve
4
A. cold water supply
B. hot water supply
C. circulation pipe
D. gas supply
18
17
12
B
E. overflow pipe
H. overflow pipe
11
3
4
7
14
5
4
C
4
6
5
4
C
4
9
D
10
13
IMD-0467 R0
Instruction manual BFM
45
6
Draining
gis
6.1 Draining unvented
installations
Some service activities require the appliance to be drained. The procedure is as
follows:
1. Shut down the appliance by setting the ON/OFF switch on the control panel
to position 0.
IMD-0462 R0
2. Isolate the water heater from the power supply by putting the isolator
between the appliance and the mains power supply to position 0.
3. Shut off the gas supply (10).
4. Close the stop valve (11) in the hot water pipe.
5. Close the supply valve of the cold water supply (A).
6. Open the drain valve (9).
7. Bleed the appliance (or installation) so that it drains completely.
46
Instruction manual BFM
gis
6.2 Draining vented
installations
Some service activities require the appliance to be drained. The procedure is as
follows:
1. Shut down the appliance by setting the ON/OFF switch on the control panel
to position 0.
IMD-0462 R0
2. Isolate the water heater from the power supply by putting the isolator
between the appliance and the mains power supply to position 0.
3. Shut off the gas supply (10).
4. Close the stop valve (11) in the hot water pipe.
5. Close the stop valve (4) between the cold water head tank and the cold
water inlet.
6. Open the drain valve (9).
7. Bleed the appliance (or installation) so that it drains completely.
Instruction manual BFM
47
6
Draining
gis
48
Instruction manual BFM
gis
7 The control panel
7.1 Introduction
7.3 Explanation of icons
Topics covered in this chapter:
The table explains the meanings of the icons.
•
•
•
•
•
Icons and their meaning
Name
Explanation
ON/OFF Switch
ON mode / OFF
mode
7.2 Control panel
Reset button with
error status
Resets burner
control
The figure shows the control panel.
The control panel
Temperature control For setting water
temperature (Tset)
7.4 ON/OFF switch
The ON/OFF switch sets the appliance in ON mode or
OFF mode. In OFF mode the appliance is still
electrically live. This ensures that the frost protection
is active.
Note
To electrically isolate the appliance, you must use
the isolator between the appliance and the mains
power supply.
7.5 Control thermostat
Use the rotary knob of the control thermostat to set the
desired water temperature between ± 40°C and ±
70°C. The range is continuous and is labelled 1
through 4. The table shows the temperatures
corresponding to the numbers on the knob.
IMD-0462 R0
The control panel comprises:
Temperature settings
•
•
•
•
an ON/OFF switch with status lamp;
a reset button with status lamp;
a control thermostat with rotary knob;
two status lamps.
Position
Temperature
± 40°C
1
2
3
4
± 50°C
± 60°C
± 70°C
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7
The control panel
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7.6 Burner control reset button
An error in the appliance can cause a lockout of the
burner control. When this happens, the reset button
lamp will be lit. Once the cause of the error has been
rectified, you can reset the appliance using the reset
button.
Note
Never use the reset button until you have rectified
the error.
according to the appliance status (8 "Status of the
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Instruction manual BFM
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8 Status of the
appliance
Once the cause has been rectified, the appliance
will restart automatically.
8.1 Introduction
Topics covered in this chapter:
•
Blocking errors
•
•
You can recognize this condition when the
appliance makes no attempt to start the heating
cycle, despite the fact that the water is colder than
the temperature set with the control
errors disappear automatically once the cause of
the error has been removed, after which the
appliance resumes operation by itself.
8.2 Operating modes
When running, the appliance has three basic
operating modes, namely:
•
ELECTRICALLY ISOLATED
In this mode, the appliance is off and no
components are live. The isolator (switch between
the appliance and the mains power supply) is off.
On the control panel:
The cause of the error is not shown on the control
panel. For a comprehensive overview of errors, refer
to troubleshooting. (11 "Troubleshooting")
-
-
the ON/OFF switch is at position 0;
the green light is dimmed.
As an end user, if you find the appliance in an error
condition, you can attempt to start the appliance
running by pressing the rest button once. However, if
the error returns or occurs several times in a short
time, you must contact your service and maintenance
engineer.
•
•
OFF
In this mode, the frost protection is activated. The
isolator is at position I. On the control panel:
-
the ON/OFF switch is at position 0;
the green light is lit.
-
ON
In this mode, the appliance continuously responds
to the heat demand. On the control panel:
-
-
the ON/OFF switch is at position I;
the water temperature can be set using the
rotary knob of the control
-
the green light is lit.
8.3 Error conditions
When the appliance is in an error condition, the heat
demand is (temporarily) ignored, and you cannot draw
hot water. The frost protection is also out of action.
The error conditions are divided into three groups:
•
Lock out errors of the burner control
In this event, the red error light will be lit in the reset
button on the control panel. The burner control is
in lockout.
Once the cause has been rectified, the reset
button must be pressed to restart the appliance.
•
Cycling of appliance
In this case, the appliance continuously attempts
to start, but there is an error that prevents the
heating cycle from completing successfully.
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Status of the appliance
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9 Starting and running
The entire cycle is explained in the example below.
9.1 Introduction
Topics covered in this chapter:
Note
•
•
The cycle has the same steps when frost
protection is activated.
9.2 Starting the appliance
Start the appliance as follows:
1. The control thermostat sensor measures the
temperature. The water temperature falls below
the set temperature of (for example) 60°C, causing
the control thermostat to close. The burner control
now detects a demand and starts the heating
cycle.
valve.
3. Switch on the power to the appliance using the
isolator between the appliance and the power
supply.
2. Following demand, the wait period starts. This wait
ensures that the ignition is safe. The wait period
lasts approximately 15 seconds.
4. Put the appliance in ON mode by setting the
3. Once the wait period has elapsed (there is audible
‘clicking’ of the relay in the burner control), the
PRE-GLOW starts.
ON/OFF-switch on the control panel to position I.
thermostat"), set the desired water temperature.
4. After about 12 seconds (pre)glowing, the gas
control opens and ignition takes place.
If there is a heat demand, the appliance will run
through the heating cycle (9.3 "The appliance's
5. After ignition, the flame is detected and the
appliance will be running. This means that actual
heating has started.
9.3 The appliance's heating cycle
6. When the water reaches the set temperature, the
demand ceases. The gas control closes and the
burner tray is extinguished. A new wait period of
about 10 seconds starts.
The appliance's heating cycle is activated as soon as
the measured water temperature
) falls below
(Twater
the threshold value (T ). This threshold value
set
depends on the currently selected appliance operating
mode. For example, if the appliance is in OFF mode
(frost protection), then this value is 20°C. If the
appliance is in ON mode, for example, then this
threshold value can be selected, e.g. position 3 (±
60°C).
7. At the end of this wait, the appliance enters the idle
state, and waits until the water temperature once
more falls below the set temperature.
With any subsequent heat demand, the heating cycle
will resume from step 1.
The heating cycle runs successively through the
following states:
1. HEAT DEMAND;
2. WAIT;
3. PRE-GLOW;
4. IGNITION;
5. RUNNING;
6. WAIT.
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Starting and running
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10 Shutting down
10.1 Introduction
Topics covered in this chapter:
•
•
•
10.2 Shutting down the appliance for a brief
period (OFF mode)
To shut the appliance down for a brief period, you must
activate frost protection using the appliance's heating
By using the frost protection, you can prevent water
freezing in the appliance. Frost protection is activated
by setting the ON/OFF switch on the control panel to
position 0.
10.3 Isolating the appliance from the mains
The appliance should only be isolated from mains
power in the correct way. The correct procedure is as
follows:
1. Shut down the appliance by setting the ON/OFF
switch to position 0.
2. Isolate the water heater from the power supply by
putting the isolator between the appliance and the
mains power supply to position 0.
10.4 Shutting the appliance down for a long
period
To shut the appliance down for a longer period, you
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10
Shutting down
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11 Troubleshooting
This chapter deals with the following problems with the appliance:
11.1 Introduction
•
•
•
•
•
•
Gas smell.
Water leakage.
Explosive ignition.
Poor flame profile.
No hot water.
Insufficient hot water.
When the appliance is in an error condition, the heat demand is (temporarily)
ignored, and you cannot draw hot water. The frost protection is also out of
action. The error conditions are divided into three groups:
•
Lock out errors of the burner control
In this event, the red error light will be lit on the control panel. The burner
control is in lockout.
Once the cause has been rectified, the reset button must be pressed to
restart the appliance.
•
•
Cycling of appliance
In this case, the appliance continuously attempts to start, but there is an
error that prevents the heating cycle (9.3 "The appliance's heating cycle")
from completing successfully. Once the cause has been rectified, the
appliance will restart automatically.
Blocking errors
You can recognize this condition when the appliance does not start running,
despite the fact that the water is colder than the temperature set with the
These errors disappear automatically once the cause of the error has been
removed, after which the appliance resumes operation by itself.
Possible error conditions are explained in the following troubleshooting tables.
Note
Footnotes referred to in the tables can be found on the last page of each
table.
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11.2 Troubleshooting: general errors
Warning
Maintenance may only be performed by a qualified service and maintenance engineer.
General errors
Symptom
Gas smell
Cause
Solution
Warning
Remark
Warning
Contact your installation engineer or local gas company
immediately.
Gas leak
Close the main gas valve immediately.
Warning
Do not operate any switches.
Warning
No naked flames.
Warning
Ventilate the boiler room.
Water leakage
Leakage from a water Tighten the threaded connection
connection (threaded)
If the leak persists, consult your installation engineer
Leakage from another Trace the leak
nearby water appliance
or pipe segment
Leakage from the
appliance's tank
Consult the supplier and/or manufacturer
Condensation
Before drawing (too much) tap water, wait until the water in the
boiler has reached the set temperature.
Explosive ignition
Poor flame profile
Incorrect supply
Set the correct supply pressure and/or burner
If ignition is not improved, consult your installation engineer.
pressure and/or burner pressure. (3.11 "Checking the supply pressure and burner
pressure
pressure")
Contaminated burner
Contaminated orifice
Clean the burner(s) (12.4.2 "Clean the burner(s)")
Clean the orifice(s) (12.4.3 "Clean the orifice(s)")
Inadequate air supply Improve the air supply by providing better ventilation in the boiler
room.
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is
Warning
Insufficient hot water
Symptom
Cause
Solution
Remark
Insufficient hot water Water temperature
Set the control thermostat (7.5 "Control thermostat") to a higher
setting (T ) is too low value
set
Hot water supply is
used up
1. Reduce hot water consumption and give the appliance time to If this error persists, check whether the high-limit thermostat is
switching.
heat up.
2. If this error persists, check whether the high-limit thermostat is
switching.
If this is the case, check that the circulation and/or top to bottom
circulation pump are working.
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is
11.4 Troubleshooting: No hot water
No hot water
Symptom
Cause
Solution
Remark
No attempt to start
heating cycle
No supply voltage
present
1. Check if the isolator is ON.
See the BFM electrical diagram (14 "Electrical diagram")
If the error cannot be rectified, contact your installation engineer
2. Check whether there is power to the isolator
3. Check whether there is power to the electrical connector block
4. Check whether there is power to the burner control
5. Check fuse in the burner control
The measured voltage must be 230 VAC (-15%, +10%).
1. Blockage in the chimney flue or air supply
No attempt to start
heating cycle (blocking closing
error)
Pressure switch not
Once the error is rectified, the appliance will automatically start up
if there is a heat demand
If the error cannot be resolved or is persistent, contact your
installation engineer
-
-
Trace the blockage
Remove the blockage
-
-
Check the wiring of the pressure switch
Failure in the
thermostat circuit
1. Check whether the control thermostat is switched (closed)
2. Check leads and sensors of the control and high-limit
thermostats
Repetitive starting of
the heating cycle
(cycling of the
Too much resistance in 1. Check whether the chimney flue configuration (3.9 "Air supply If the error cannot be resolved or is persistent, contact your
the chimney flue (the
pressure switch opens
during heating)
installation engineer
and flue") has been installed in accordance with instructions
appliance)
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Symptom
Cause
Solution
Remark
Burner control reset
button (burner control cause the error to appear again:
lock out error)
There are three possible causes for this error. In order to determine the cause, you must
see the appliance's heating cycle (9.3 "The appliance's heating
cycle")
1. Reset the appliance by pressing the reset button 1x
2. Cause (a) occurs between step 4 and step 5 of the heating cycle
3. Cause (b) occurs in step 5 or 6
4. Cause (c) occurs in step 7
(a) Continuous failure 1. Check whether the thermostat is defective
If the error cannot be resolved or is persistent, contact your
installation engineer
in the safety circuit
2. Check whether the sensor of the thermostat is defective
3. Check the leads of the thermostat
(b) Failed start attempt No gas:
If the error cannot be resolved or is persistent, contact your
installation engineer
1. Check that the gas valve is open
2. Check whether the gas control is opening (clicking of the gas
control)
3. Check the leads of the gas control
No ignition:
1. Check whether the spark igniter is sparking in the pilot flame
cap
2. Check the leads of the glow igniter
3. Check whether the spark igniter is correctly mounted in the
bracket
No flame detection:
1. Check whether the flame probe is defective
2. Check that the flame probe leads are properly connected
(c) Failure in the safety 1. Check whether the control thermostat is working
If the error cannot be resolved or is persistent, contact your
installation engineer
circuit during heating
2. Check whether the high-limit thermostat is working
(the safety thermostat
has switched)
3. Check that the circulation pump (if present) is working
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Instruction manual BFM
62
s
12 Performing
maintenance
Caution
12.1 Introduction
Maintenance may only by carried out by an approved service and
maintenance engineer.
At each service, the appliance undergoes maintenance on both the water side
and the gas side. The maintenance must be carried out in the following order.
Note
Before ordering spare parts, it is important to write down the appliance type
and model, and the full serial number of the appliance. These details can be
found on the rating plate. Only by ordering with this information can you be sure
to receive the correct spare parts.
To test whether all components are still working properly, complete the following
steps:
12.2 Preparation for
maintenance
1. Set the ON/OFF switch on the control panel to position 0.
2. Set the control thermostat to the highest value (note the original setting) and
set the ON/OFF switch back again to position I.
3. If there is no heat demand, draw off some water to create a heat demand.
correctly.
5. Set the control thermostat back to the original setting and set the ON/OFF
switch back again to position I.
and burner pressure"), and adjust them if necessary.
7. Check that all components of the chimney flue system are properly attached.
8. Test the operation of the overflow valve of the protected cold supply set-up.
The water should spurt out.
9. Test the overflow operation of the T&P valve. The water should spurt out.
10. Test the overflow operation of the T&P valve. The water should spurt out with
a strong jet.
11. Check the drainpipes from the discharge points of all valves and remove any
scale deposits that may be present.
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12
Performing maintenance
s
12.3 Water-side mainte-
nance
12.3.1 Introduction
The following steps must be carried out on the water side:
12.3.2 Checking the anodes
Timely replacement of the anodes extends the service life of the appliance. The
appliance's anodes must be replaced as soon as they are 60% used or more
(take this into consideration when determining the maintenance frequency).
1. Remove the chimney flue components from the top box.
2. Remove the cover from the top box.
3. Disconnect the fan leads and withdraw the cable through the strain relief.
4. Undo the screws in the top box.
5. Remove the top box from the appliance.
6. Undo the screws of the lid in the top side of the appliance.
7. Remove the lid from the appliance.
8. Remove the sealing ring from the appliance.
9. Loosen the anodes using suitable tools.
10. Check the anodes, and if necessary, replace them.
necessary, replace them.
12. Place a new sealing ring on the rim of the tank and re-fit the lid.
13. Re-fit the top box.
14. Feed the fan cable through the strain relief and connect the leads to the fan.
See addendum A: BFM electrical diagram.
15. Re-fit the cover on the top box.
12.3.3 Descaling and cleaning the tank
Scale and lime buildup prevent effective conduction of the heat to the water.
Periodic cleaning and descaling prevents buildup of these deposits. This
increases the service life of the appliance, and also improves the heating
process.
Take the rate of scale formation into account when deciding on maintenance
frequency. Scale formation depends on the local water composition, the water
consumption and the water temperature setting. A water temperature setting of
maximum 60°C is recommended for prevention of excessive scale buildup.
To ensure the perfectly watertight sealing of a cleaning opening, the gasket (6),
O-ring (7), sealing rings (4), bolts (3) and possibly the lid (5) should be replaced
with new components after opening (see the figure). A special set is obtainable
from the supplier/manufacturer.
To simplify the task of descaling and cleaning the tank, the appliance is
equipped with two cleaning openings.
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2
1
5
7
6
3
4
IMD-0235 R2
1. Remove the cover plate (1) on the outer jacket (see the figure).
2. Carefully remove the insulation layer (2) and set it to one side. This will be
needed again later.
3. Undo the bolts.
4. Remove the lid, the gasket and the O-ring.
5. Inspect the tank and remove the loose scale deposits and contamination.
6. If the scale cannot be removed by hand, descale the appliance with a
descaling agent. Contact the supplier/manufacturer for advice on what
descaling agent to use.
1
3
6
5
4
2
IMD-0282 R1
7. Close the cleaning opening. To avoid damage to the tank, tighten the bolts
that fasten the lid with a torque no greater than 50 Nm. Use suitable tools for
this. For the best possible watertight seal of the cleaning opening, the bolts
in the lid should be torqued down in the sequence shown in the figure.
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12
Performing maintenance
s
12.4 Gas-side mainte-
nance
12.4.1 Introduction
The following steps must be carried out on the gas side:
12.4.2 Clean the burner(s)
1. Detach the burner(s)
2. Remove all contamination present on the burner(s).
3. Fit the burner(s)
12.4.3 Clean the orifice(s)
1. Detach the orifice(s)
2. Remove all contamination present in the orifice(s).
3. Fit the orifice(s)
12.4.4 Checking the flue baffles
Warning
The flue baffles can be hot.
1. Remove the flue baffles from the appliance.
2. Check the flue baffles for the presence of corrosion, removing this if
necessary.
3. Check the flue baffles for wear, and replace the flue baffles if necessary.
To finalise the maintenance, carry out the following steps:
12.5 Finalising mainte-
nance
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13 Warranty (certificate)
To register your warranty, you should complete and return the enclosed
warranty card after which a warranty certificate will be sent to you. This
certificate gives the owner of a appliance supplied by A.O. Smith Water
Products Company B.V. of Veldhoven, The Netherlands (hereinafter "A.O.
Smith") the right to the warranty set out below, defining the commitments of A.O.
Smith to the owner.
If within one year of the original installation date of a water heater supplied by
A.O. Smith, following verification, and at the sole discretion of A.O. Smith, a
section or part (with exclusion of the tank) proves to be defective or fails to
function correctly due to manufacturing and/or material defects, then A.O. Smith
shall repair or replace this section or part.
13.1 General warranty
13.2 Tank warranty
If within 3 years of the original installation date of a water heater supplied by
A.O. Smith, following inspection, and at the sole discretion of A.O. Smith, the
glass-lined steel tank proves to be leaking due to rust or corrosion occurring on
the water side, then A.O. Smith shall offer to replace the defective water heater
with an entirely new water heater of equivalent size and quality. The warranty
period given on the replacement water heater shall be equal to the remaining
warranty period of the original water heater that was supplied. Notwithstanding
that stated earlier in this article, in the event that unfiltered or softened water is
used, or allowed to stand in the water heater, the warranty shall be reduced to
one year from the original installation date.
The warranty set out in article 1 and 2 will apply solely under the following
conditions:
13.3 Conditions for Instal-
lation and use
a. The water heater is installed under strict adherence to A.O. Smith
installation instructions for the specific model, and the relevant
government and local authority installation and building codes, rules and
regulations in force at the time of installation.
b. The water heater remains installed at the original site of installation.
c. The appliance is exclusively used with drinking water, which at all times
can freely circulate (a separately installed heat exchanger is mandatory
for heating salt water or corrosive water).
d. The tank is safeguarded against harmful scaling and lime buildup by
means of periodic maintenance.
e. The water temperatures in the heater do not exceed the maximum
setting of the thermostats, which form a part of the water heater.
f. The water pressure and/or heat load do not exceed the maximum values
stated on the water heater rating plate.
g. The water heater is installed in a non-corrosive atmosphere or
environment.
h. The water heater is connected to a protected cold supply arrangement,
which is: approved by the relevant authority; with sufficient capacity for
this purpose; supplying a pressure no greater than the working pressure
stated on the water heater; and where applicable by a likewise approved
temperature and pressure relief valve, fitted in accordance with
installation instructions of A.O. Smith applying to the specific model of
water heater, and further in compliance with the government and local
authority installation and building codes, rules and regulations.
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13
Warranty (certificate)
gis
i. The appliance is at all times fitted with cathodic protection. If sacrificial
anodes are used for this, these must be replaced and renewed when,
and as soon as, they are 60% or more consumed. When electric anodes
are used, it is important to ensure that they continue to work properly.
The warranty set out in articles 1 and 2 will not apply in the event of:
a. damage to the water heater caused by an external factor;
13.4 Exclusions
b. misuse, neglect (including frost damage), modification, incorrect and/or
unauthorised use of the water heater and any attempt to repair leaks;
c. contaminants or other substances having been allowed to enter the tank;
d. the conductivity of the water being less than 125 µS/cm and/or the
hardness (alkaline-earth ions) of the water being less than 1.00
e. unfiltered, recirculated water flowing through or being stored in the water
heater;
f. any attempts at repair to a defective water heater other than by an
approved service engineer.
The obligations of A.O. Smith pursuant to the specified warranty do not extend
beyond free delivery from the Veldhoven warehouse of the replacement
sections, parts or water heater respectively. Shipping, labour, installation and
any other costs associated with the replacement will not be accepted by A.O.
Smith.
13.5 Scope of the
warranty
A claim on grounds of the specified warranty must be submitted to the dealer
from whom the water heater was purchased, or to another authorised dealer for
A.O. Smith Water Products Company products. Inspection of the water heater
as referred to in articles 1 and 2 shall take place in one of the laboratories of
A.O. Smith Water Products Company.
13.6 Claims
A.O. Smith grants no other warranty or guarantee over its water heaters nor the
(sections or parts of) water heaters supplied for replacement, other than the
warranty expressly set out in this Certificate.
13.7 Obligations of A.O.
Smith
Under the terms of the supplied warranty, A.O. Smith is not liable for damage to
persons or property caused by (sections or parts, or the glass-lined steel tank
of) a (replacement) water heater that it has supplied.
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Electrical diagram
is
14.2 BFM Electrical
Diagram.
1
2
PVC PVC
NO NC
230VAC
50 Hz
FAN
L
N
L
N
S
1
S
2
S
3
S
4
3
4
5
6
7
8
9
10
11
0305485 R2
1 = brown, 2 = blue, 3 = yellow/green, 4 = black, 5 = white, 6 = red, 7 = white/orange, 8 = white/purple,
9 = black/green, 10 = black/red, 11 = black/white
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COMPONENTS:
A
B
C
D
E
F
Mantle
Isolating transformer
DPS (Differential air pressure switch)
Filter
Reset button
Frost thermostat
Control thermostat
ON/OFF switch
Safety thermostat
High-limit thermostat
Burner control
Terminal block
Earth strip
G
H
K
L
M
N
P
R
Relay
OPTIONAL COMPONENTS
S
T
Clock
Potentiostat
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14
Electrical diagram
is
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Index
A
M
maintenance
B
C
connect
O
P
R
S
D
E
F
symbol
T
G
to shut down
H
I
U
W
water
L
Instruction manual BFM
73
Index
Instruction manual BFM
0306 723
4.0 UK
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