Select a fault code

Pump detected running without adequate water.

Internal electronics fault detected on the control board.

Flow temperature exceeded safe limits.

Flow temperature sensor fault — reading outside normal range.

The burner has failed to ignite or the flame sensor has not detected a flame.

Flue gas thermostat or combustion air supply issue.

Boiler locked out after repeated ignition failures.

Combustion fan not operating correctly.

System pressure approaching minimum — not yet a lockout.

Annual service interval has been exceeded.