Cause of error code FLU

Blocked Vent Pressure Switch

Solution for error code FLU

- Check the flue vent to be sure it is not blocked or damaged.
- Check the switch wiring by applying a jumper in place of the switch. If the code clears with the jumper in place, REPLACE the flue switch and connect the wires to the new switch BEFORE running the boiler.

WARNING: Do not use jumper to remedy this error. Faulty switches MUST be replaced. Failure to do so could result in serious injury or death.