AO Smith Water Heater 305 User Manual

A. O.SMITH’S  
INNOVATION ON DEMAND  
A. O. Smith’s complete line of tankless gas water heaters  
A Variety of Sleek, Compact Indoor Models To Choose From  
ATI-305-N (Natural Gas), ATI-305-P (Propane)  
ATI-505-N (Natural Gas), ATI-505-P (Propane)  
ATI-705-N (Natural Gas), ATI-705-P (Propane)  
ATI-705A-N (Natural Gas), ATI-705A-P (Propane) Commercial  
305 and 505 Models  
705 Model  
Model Dimensions  
305 and 505  
inches (mm)  
705  
inches (mm)  
Dimension  
Description  
A
B
C
D
E
F
G
H
I
Width  
14 (355.6)  
9.6 (244.5)  
22.9 (582)  
25.5 (648.2)  
3.6 (91)  
18.5 (470)  
9.3 (230.5)  
23.6 (600)  
25.2 (640)  
4.5 (115)  
2.4 (61)  
Depth  
Height - Unit  
Height - with brackets  
Hot Water Outlet - from wall*  
Hot Water Outlet - from center  
Cold Water Inlet - from wall*  
Cold Water Inlet - from center  
Gas Connection - from wall*  
4.3 (110)  
2.8 (70)  
3.9 (99)  
1.1 (27)  
2.0 (52)  
4.3 (109)  
2.4 (61.2)  
J
Gas Connection - from center  
From base to gas connection  
3.5 (89)  
1.6 (40)  
4.3 (110)  
1.6 (40)  
K
From base to cold connection  
From base to hot connection  
2.0 (50)  
1.6 (41)  
2.0 (50)  
1.6 (41)  
All Models Available  
In Both Natural Gas  
And Propane Designs  
* This is the minimum dimension from the wall. The wall bracket is adjustable to allow an additional  
1.57 inches (40mm).  
A. O. Smith On-Demand Gas Water Heaters  
Residential and Commercial Product Features:  
Outlet Flow Data  
Innovative Technology  
Excellent Performance  
A variety of indoor installation options  
12-year limited warranty on heat  
exchanger, 5-year warranty on all parts  
Continuous hot water on demand (up to 9.8 GPM)  
Models available that meet requirements  
of ASME Boiler and Pressure Vessel Code  
Whole house water heating solution  
Direct electronic ignition – no pilot light  
On-board diagnostics and safety monitoring  
Energy Efficiency  
Interior sealed combustion  
(does not use interior combustion air)  
Up to 84% thermal efficiency, providing  
significant energy cost savings  
Model Specifications  
Model  
305  
505  
705  
Minimum Gas Consumption Btu/h  
Maximum Gas Consumption Btu/h  
15,000  
19,000  
237,000  
199,000 Natural Gas  
190,000 Propane Gas  
Hot water capacity (Min - Max)*  
Hot water capacity (45°F rise)  
0.6 - 5.3 GPM  
0.6 - 8.5 GPM  
0.6 - 9.8 GPM  
(2.3 - 20.1 L/min)  
(2.3 - 32.0 L/min)  
(2.3 - 37 L/min)  
7.4 GPM (28.0 L/min)  
Natural Gas  
7.1 GPM (26.9 L/min)  
Propane Gas  
5.3 GPM  
(20.1 L/min)  
8.8 GPM  
(33.5 L/min)  
Default Temperature Setting (no controller)  
Remote Controller Default Temperature Setting  
Maximum Temp Setting (Commercial**)  
Maximum Temp Setting (Residential)  
Minimum Temperature Setting  
Weight  
120º F (49º C)  
104º F (40º C)  
160º F (71º C)  
185º F (85º C)  
140º F (60º C)  
98º F (37º C)  
50 lb (23 kg)  
55 lb (25 kg)  
Efficiency Rating  
84%  
Noise level  
49 dB  
Electrical Consumption  
By-Pass Control  
Normal  
79 W  
2.8 W  
100 W  
99 W  
2 W  
Standby  
Anti-frost Protection  
116 W  
Fixed  
Electronic  
Minimum Gas Supply Pressure Natural Gas  
Propane  
5.0 inch W.C.  
8.0 inch W.C.  
10.5 inch W.C.  
13.5 inch W.C.  
Maximum Gas Supply Pressure Natural Gas  
Propane  
Type of Appliance  
Direct Vent, Temperature controlled continuous flow gas hot water system.  
With or without remote controls, mounted in kitchen, bathroom, etc.  
Natural Gas or Propane - Ensure unit matches gas type it's being installed on.  
Gas Supply: 3/4˝ MNPT, Cold Water Inlet: 3/4˝ MNPT, Hot Water Outlet: 3/4˝  
Direct Electronic Ignition  
Operation  
Approved Gas Type  
Connections  
Ignition System  
Electric Connections  
Water Temperature Control  
Water Supply Pressure  
Maximum Water Supply Pressure  
Remote Control Cable  
Appliance: AC 120 Volts, 60Hz. Remote Control: DC 12 Volts (Digital)  
Simulation Feedforward and Feedback.  
Minimum Water Pressure: 20 PSI (Recommended 30-80 PSI for maximum  
150 PSI  
Non-Polarized Two Core Cable (Minimum 22 AWG)  
* Minimum flow may vary slightly depending on the temperature setting and the inlet water temperature.  
** for commercial and hydronic applications requiring higher temperatures  
Specifications are subject to change without prior notice.  
The maximum inlet gas pressure must not exceed the value specified by the manufacturer. The minimum value listed is for the purpose of input adjustment.  
500 Tennessee Waltz Parkway  
Ashland City, TN 37015  
AMGSS00207 ©2007 A. O. Smith Corporation  
A. O. Smith reserves the right to make product changes or improvements at any time without notice.  
Printed in U.S.A  

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