Medium
F.83 on Vaillant ecoTEC Plus 826

Your boiler is struggling to detect consistent water temperatures, meaning it cannot properly manage its internal heating cycle.

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

Fault: Flow and/or return temperature sensor temperature change

Engineer required

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

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Related fault codes

F.73View →F.74View →

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