1) Turn off power supply. 2) Check that all wire connections are secure and free of burns. The flow adjustment valve is located behind the…

ABNORMAL FAN MOTOR 1) Turn off power supply. 2) Check fan motor wiring for any breakages, burn marks on the PC board, or moisture. If…

ABNORMAL GAS VALVES Driving circuit fault for the main or solenoid gas valves. 1) If the hot water is shut off, but flames are still…

Part of an Easy?Link system (510 (T?D2) only), the master unit signaled for an additional heater to activate and it did not. 1) Verify that…

1) Check that the wire connections are secure and free of burns or cuts. 2) Check that the clear plastic tube connecting the proportional gas…

MIXING THERMISTOR 1) Check that the wire connections are secure and free of burns or cuts. The mixing thermistor is embedded in the water outlet…

1) Check that the wire connections are secure and free of burns or cuts. The inlet thermistor is embedded in the water inlet connection. 2)…

OUTPUT THERMISTOR 1) Check that the wire connections are secure and free of burns or cuts. The output thermistor is located on the heat exchanger…

FLAME LOSS This error code appears if the flames disappear while the unit is still supposed to be in operation. 1) Verify that the hi?limit…

IGNITION FAILURE Heater does not fire after three failed attempts at ignition. 1) Verify that the hi?limit switch is not tripped. Turn the power off…