State 520 - Manual (Page 43)

Troubleshooting
43 │
Page
‐FAULT ANALYSIS OF ERROR CODES‐
If there is a problem with the installation of the water heater, it will display a numerical error
code on the
3‐digit 7‐Seg. LED of the computer board or the remote controller (if installed) to
communicate the source of the problem.
Error
Code
Malfunction description Diagnosis
031 Incorrect dipswitch settings
Check the dipswitch
settings on PCB
101 Warning for the “991” error code
Call the
manufacturer’s
Technical Dept.
at 1‐877‐737‐2840
111 Ignition failure
Check gas supply
121 Loss of flame
311 Output thermistor failure
Call the
manufacturer’s
Technical Dept.
at 1‐877‐737‐2840
321 Inlet thermistor failure
331 Mixing thermistor failure
341
Exhaust thermistor failure (Direct Vent Indoor models
only)
391 Air‐fuel Ratio Rod Failure
441 Flow Sensor Failure (Only Easy‐Link system)
510 Abnormal Main Gas Valve
551 Abnormal Gas Solenoid Valve
611 Fan Motor Fault
621
Exhaust fan motor Fault (Direct Vent Indoor models
only)
631 Abnormal External Pump
651
Water Control Valve Fault (Flow Adjustment function)
(Only Easy‐Link system)
661 Water Control Valve Fault (Bypass valve function)
701 Computer board Fault
711 Gas Solenoid Valve drive circuit failure
721 False Flame Detection
741
Miscommunication between water heater and
remote controller
761
Miscommunication in Easy‐Link (520 (T‐H2) models
only)
941
Abnormal exhaust temperature (Direct Vent Indoor
models only) Lower the set
temperature
991 Imperfect combustion
Call the
manufacturer’s
Technical Dept.
at 1‐877‐737‐2840