High Lockout
FAN LOCKOUT on Potterton Promax 15/2 HE Plus

Your boiler has stopped working because the internal fan, which safely exhausts gases, is unable to start or spin 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

Lights: Flash Flash On. NOTE: The fan is supplied with 325 Vdc. Check continuity from N to O & from P to Q on 3-way PCB connector. Check continuity from R to S & from T to U & from V to W on smaller 6-way PCB connector.

What causes this fault?

This fault occurs when the boiler's control board cannot detect the fan spinning at the speed required to safely clear waste gases from the system. The most common physical causes are a buildup of dirt or debris in the fan blades, a complete motor failure, or a loose electrical connection 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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Related fault codes

FLASH OFF ONView →FLASH ON FLASHView →

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