High
F.37 on Vaillant ecoTEC plus aquaPLUS

Your boiler has stopped working because the fan that helps remove exhaust gases is not 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.

What the manual says

Manufacturer manual

The rotary speed of the fan is too high or too low | Air pressure switch defect; fan defect; electronics defect

From this model's manual
Verified against the Vaillant Ecotec Plus Aquaplus installation & service manual, page 41.
Plain-English guidance below. Severity, DIY steps, costs and parts are our interpretation to help you act, not text from the manual.

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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