Medium
d.41 on Vaillant ecoFIT Pure 412

Your boiler is struggling to accurately detect the temperature of the water returning to it, which may prevent your heating system from working correctly.

Reviewed by the BoilerFaultCodes Editorial Team · Last reviewed

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This fault should be looked at by a Gas Safe engineer within the next week or two. It may get worse if left.

Technical description

Heating return temperature

Engineer required

This fault requires a Gas Safe registered engineer. Do not attempt gas-related repairs yourself.

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Related fault codes

d.40View →d.41View →

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