Medium
F.86 on Vaillant Home System

Your boiler has detected an issue with the electrical connection to your underfloor heating system, preventing that part of your home from warming up properly.

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

Underfloor heating contact fault

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.83View →F.84View →F.85View →

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