Your boiler has detected an issue with the air fan system and has safely shut down to prevent the appliance from starting incorrectly.

Fan shut down during safety time

What causes this fault?

This fault occurs when the boiler's control system loses communication with the fan or detects that it isn't spinning at the required speed during its startup safety checks. The most common reason is a mechanical failure within the fan motor or a fault in the electronic control board that prevents power from reaching the fan. Without a functioning fan to safely clear exhaust gases, the boiler is programmed to shut down immediately.