Error Codes - A.O. Smith T-H2S-DV Troubleshooting Manual

5.3 TROUBLESHOOTING ‐ ERROR CODES
•
All units are self diagnostic for safety and convenience when trouble shooting.
•
If there is a problem with the installation or the unit, it will display a numerical error code on
the TM‐RE30 Remote Controller (if installed) or on the 3‐digit 7‐Seg LED at the center of the
computer board to communicate the source of the problem.
•
Consult the following chart for the cause of each error code.
7‐Seg LED
Figure 4
Table 3 – Error Codes
Error Symptom
031 Incorrect Dipswitch
Settings
101 Warning for 991
Error Code
111 Ignition Failure
121 Flame Loss
311 Output Thermistor
321 Inlet Thermistor
331 Mixing Thermistor
341 Exhaust Thermistor
SINGLE UNIT
• The 3‐digit 7‐Seg LED displays error code, or the TM‐RE30 (if installed) displays the 3‐digit error code.
EASY‐LINK SYSTEM
The 7‐Seg LED of the individual unit with the error in question displays the whole 3‐digit error code.
The TM‐RE30 (if installed) displays a 3‐digit number which signifies which unit has the error, and what
the error code is.
Error Symptom
391 Air‐fuel Ratio Rod Failure
441 Flow Sensor
510 Abnormal Main and
Solenoid Gas Valve
551 Solenoid Valves
611 Abnormal Fan Motor
621 Exhaust Fan Motor
(Indoor models only)
631 External Pump
651 Abnormal Flow
Adjustment Valve
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Troubleshooting Guide
Figure 5 – TM‐RE30 (Optional)
Error Symptom
661 Abnormal Water Bypass Valve
701 Proportional Valve /
Computer
711 Hi‐Limit switch /
Overheat Cutoff Fuse
721 False Flame Detection
741 Remote Controller
Communication Failure
761 Communication Failure
(Easy‐Link)
941 Abnormal Exhaust
Temperature
991 Abnormal combustion