Service Manual

2
2
Ultra Low NOx Atmospheric Vent Water Heaters
with Direct Spark Ignition
Table of Contents
Serial Number Breakdown……………………………………………………………………………………………...3
How to Use This Manual ................................................................................................................................. 4
Tools Required for Service ............................................................................................................................. 5
Specifications .................................................................................................................................................. 6
Sequence of Operation ................................................................................................................................... 9
Troubleshooting ............................................................................................................................................ 13
Service Procedure I: Thermostat Circuit Testing and Replacement......................................................... 23
Service Procedure II: Combustion System Testing and Replacement ..................................................... 27
Service Procedure III: Burner Tube Inspection and Replacement ............................................................ 31
Service Procedure IV: Gas Valve Replacement.......................................................................................... 33
Service Procedure V: Blower Testing and Replacement ........................................................................... 34
Service Procedure VI: Flame Sensor Testing and Replacement............................................................... 36
Service Procedure VII: Spark Rod Gap Adjustment and Replacement..................................................... 38
Service Procedure VIII: Ignition Module/Control Board Replacement ...................................................... 40
Service Procedure IX: Blocked Vent Switch Inspection and Replacement .............................................. 41
Service Procedure X: Anode Inspection and Replacement....................................................................... 42
Service Procedure XI: Display Module Replacement................................................................................. 43
Service Procedure XII: Transformer Replacement..................................................................................... 44
Water Heater Installation Checklist .............................................................................................................. 45
Water Heater Service Report ........................................................................................................................ 46
Notes .............................................................................................................................................................. 47