AO Smith Boiler HW 610 User Manual

MODELS HW 300, 399, 420, 520, 610, 670  
GAS-FIRED COMMERCIAL COPPER BOILERS FOR  
HYDRONIC HEATING AND HOT WATER SUPPLY  
UP-FLOW MODELS  
• INSTALLATION • OPERATION MAINTENANCE • LIMITED WARRANTY  
• INDOOR ONLY  
WARNING: If the information in this manual  
is not followed exactly, a fire or explosion  
may result causing property damage,  
personal injury or death.  
— Do not store or use gasoline or other  
flammable vapors and liquids in the  
vicinity of this or any other appliance.  
— WHAT TO DO IF YOU SMELL GAS  
• Do not try to light any appliance.  
• Do not touch any electrical switch; do  
not use any phone in your building.  
• Immediately call your gas supplier  
from a neighbor's phone. Follow the  
gas supplier's instructions.  
• If you cannot reach your gas supplier,  
call the fire department.  
— Installation and service must be  
500 Tennessee Waltz Parkway  
performed by a qualified installer,  
service agency or the gas supplier.  
Ashland City, TN 37015  
PLACE THESE INSTRUCTIONS ADJACENT TO BOILER AND  
NOTIFY OWNER TO KEEP FOR FUTURE REFERENCE  
PRINTED 0210  
317693-000  
SAFE INSTALLATION, USE AND SERVICE  
The proper installation, use and servicing of this water heater is extremely important to your safety and the safety of others.  
Many safety-related messages and instructions have been provided in this manual and on your own water heater to warn you and others  
of a potential injury hazard. Read and obey all safety messages and instructions throughout this manual. It is very important that the  
meaning of each safety message is understood by you and others who install, use, or service this water heater.  
This is the safety alert symbol. It is used to alert you to  
potential personal injury hazards. Obey all safety  
messages that follow this symbol to avoid possible  
injury or death.  
DANGER indicates an imminently  
hazardous situation which, if not avoided,  
will result in injury or death.  
DANGER  
WARNING indicates a potentially hazardous  
situation which, if not avoided, could result  
in injury or death.  
WARNING  
CAUTION indicates a potentially hazardous  
situation which, if not avoided, could result in  
minor or moderate injury.  
CAUTION  
CAUTION used without the safety alert  
symbol indicates a potentially hazardous  
CAUTION  
situation which, if not avoided, could result in  
property damage.  
All safety messages will generally tell you about the type of hazard, what can happen if you do not follow the safety message, and how  
to avoid the risk of injury.  
The California Safe Drinking Water and Toxic Enforcement Act requires the Governor of California to publish a list of substances known to  
the State of California to cause cancer, birth defects, or other reproductive harm, and requires businesses to warn of potential exposure  
to such substances.  
This product contains a chemical known to the State of California to cause cancer, birth defects, or other reproductive harm. This appliance  
can cause low level exposure to some of the substances listed in the Act.  
IMPORTANT DEFINITIONS  
Qualified Installer: A qualified installer must have ability equivalent to a licensed tradesman in the fields of plumbing,  
air supply, venting and gas supply, including a thorough understanding of the requirements of the National Fuel Gas  
Code or the Natural Gas and Propane Installation Code as it relates to the installation of gas fired boilers. The qualified  
installer must have a thorough understanding of this instruction manual.  
Service Agency: A service agency also must have ability equivalent to a licensed tradesman in the fields of plumbing,  
air supply, venting and gas supply, including a thorough understanding of the requirements of the National Fuel Gas  
Code as it relates to the installation of gas fired boilers. The service agency must also have a thorough  
understanding of this instruction manual, and be able to perform repairs strictly in accordance with the service guidelines  
provided by the manufacturer.  
Gas Supplier: The Natural Gas or Propane Utility or service who supplies gas for utilization by the gas burning  
applianceswithinthisapplication. Thegassuppliertypicallyhasresponsibilityfortheinspectionandcodeapprovalof  
gas piping up to and including the Natural Gas meter or Propane storage tank of a building. Many gas suppliers also  
offer service and inspection of appliances within the building.  
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GENERAL SAFETY  
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TABLE OF CONTENTS  
SAFE INSTALLATION, USE AND SERVICE.......................................................................................................................................................................... 2  
GENERAL SAFETY................................................................................................................................................................................................................ 3  
TABLE OF CONTENTS.......................................................................................................................................................................................................... 4  
DIMENSIONS AND CAPACITY DATA.................................................................................................................................................................................... 5  
INTRODUCTION.................................................................................................................................................................................................................... 7  
Grounding Instructions ................................................................................................................................................................................................... 7  
Correct Gas.................................................................................................................................................................................................................... 7  
Precautions .................................................................................................................................................................................................................... 7  
Liquid Petroleum Gas Models ........................................................................................................................................................................................ 7  
High Altitude Installations ............................................................................................................................................................................................... 7  
CONTROLS AND FUNCTION................................................................................................................................................................................................ 8  
High Limit ....................................................................................................................................................................................................................... 8  
Intermittent Ignition Control Module ............................................................................................................................................................................... 8  
Thermal Balancer........................................................................................................................................................................................................... 9  
Auto Reset High Limit Control........................................................................................................................................................................................ 9  
Safety Flow Switch......................................................................................................................................................................................................... 9  
Safety Relief Valves...................................................................................................................................................................................................... 10  
Tank Temperature Control.............................................................................................................................................................................................11  
Thermometers (not installed) ....................................................................................................................................................................................... 12  
DRAIN VALVE ...................................................................................................................................................................................................................... 12  
GENERAL ............................................................................................................................................................................................................................ 12  
Required Ability ............................................................................................................................................................................................................ 12  
Location........................................................................................................................................................................................................................ 12  
Air Requirements.......................................................................................................................................................................................................... 13  
Chemical Vapor Corrosion............................................................................................................................................................................................ 13  
Installation Clearances................................................................................................................................................................................................. 14  
Leveling........................................................................................................................................................................................................................ 14  
System Connections .................................................................................................................................................................................................... 14  
VENTING ............................................................................................................................................................................................................................. 14  
Venting the Boiler ......................................................................................................................................................................................................... 14  
Venting Maintenance.................................................................................................................................................................................................... 16  
Venting Sidewall........................................................................................................................................................................................................... 16  
Venting System ............................................................................................................................................................................................................ 16  
Venting Tables.............................................................................................................................................................................................................. 17  
SYSTEM INSTALLATIONS .................................................................................................................................................................................................. 18  
Installations .................................................................................................................................................................................................................. 18  
Conventional ........................................................................................................................................................................................................ 18  
Linear Temp.......................................................................................................................................................................................................... 18  
Water Supply Line................................................................................................................................................................................................ 19  
Expansion Tank.................................................................................................................................................................................................... 19  
Vent Valves........................................................................................................................................................................................................... 20  
Manifold Headers................................................................................................................................................................................................. 20  
Cooling Piping ...................................................................................................................................................................................................... 20  
Circulating Pump.................................................................................................................................................................................................. 20  
Gas Connections.......................................................................................................................................................................................................... 20  
Gas Supply Line Purging and Sizing............................................................................................................................................................................ 21  
Gas Pressure Regulators............................................................................................................................................................................................. 22  
WIRING ................................................................................................................................................................................................................................ 23  
WIRING DIAGRAMS....................................................................................................................................................................................................... 24-33  
PIPING ............................................................................................................................................................................................................................ 34-39  
OPERATION AND START-UP INSTRUCTIONS.................................................................................................................................................................. 39  
Important ...................................................................................................................................................................................................................... 39  
Filling the System......................................................................................................................................................................................................... 39  
Pilot Alignment and Main Burner.......................................................................................................................................................................................... 39  
Lighting Instructions ................................................................................................................................................................................................ 43-44  
Checking and Adjusting Input....................................................................................................................................................................................... 41  
Operating Sequence .................................................................................................................................................................................................... 42  
REMOVAL OF EXISTING BOILER FROM A COMMON VENTING SYSTEM ..................................................................................................................... 45  
GENERAL MAINTENANCE ................................................................................................................................................................................................. 45  
Cleaning and Flushing Instructions ...................................................................................................................................................................................... 46  
PRE TROUBLESHOOTING................................................................................................................................................................................................. 46  
TROUBLESHOOTING .................................................................................................................................................................................................... 47-54  
LIMITED WARRANTY.......................................................................................................................................................................................................... 55  
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