High Lockout
F.32 on Vaillant ecoMAX

Your boiler’s air fan is not spinning at the correct speed to safely push exhaust fumes out of the flue, causing the system to shut down for safety.

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 fault (speed out of range/tolerance)

What causes this fault?

This fault occurs when the boiler's control system detects that the fan is spinning too slowly or not at all, meaning it cannot safely clear exhaust gases. The most common reasons are a build-up of dirt within the fan casing, a mechanical failure where the motor has burnt out, or a communication issue between the fan and the main circuit 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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