High Lockout
Fan speed on Potterton Envoy 30

Your boiler has stopped working because the internal fan, which safely clears exhaust gases, isn't spinning at the correct speed.

Reviewed by the BoilerFaultCodes Editorial Team · Last reviewed

Call an engineer soon

Book a Gas Safe engineer within 24 to 48 hours. Your boiler may be unsafe or could break down completely if left.

Technical description

Fan speed incorrect See chart

What causes this fault?

This fault occurs when the boiler's processor detects that the fan is not rotating fast enough to safely expel waste gases from the flue. The most common reasons are a build-up of dirt within the fan housing, worn-out bearings that cause the motor to seize, or a communication failure between the fan and the main control board.

Engineer required

This is a high severity fault. Stop using the boiler and call a Gas Safe registered engineer. Do not attempt gas-related repairs yourself.

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