Service Manual

35
3 Troubleshooting (continued)
Table 3F (continued from previous page) Troubleshooting Chart - Fault Messages Displayed on Water Heater Interface
FAULT DESCRIPTION CORRECTIVE ACTION
Low 24 VAC
120 VAC input to the main control board has
dropped below 80 VAC.
• Check 120 VAC supply to the transformer.
• Check wiring connections at the low voltage terminal
strip.
• Check the wire size/length to remote devices.
• Replace the transformer.
Watch Dog Error
The main control board has detected an
internal fault.
• Replace the main control board.
Write EEProm
The main control board has detected an
internal fault.
• Replace the main control board.
CRC Parameters
The main control board has detected an
internal fault.
• Replace the main control board.
No Error Stored
The main control board has detected an
internal fault.
• Replace the main control board.
Fatal Error
Parameters
The main control board has detected an
internal fault.
• Restore the default parameters.
• Replace the main control board.
• Replace the display board.
Service Manual