High
F.71 on Vaillant ecoFIT Pure 835

Your boiler is struggling to accurately measure the temperature of the water flowing into your heating system, so it has stopped working to prevent potential damage.

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

Flow temperature sensor fixed value fault

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

F.72View →F.73View →

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