Medium
30-80 (M, L, M, L, M, M) on Chaffoteaux Calydra 100

Your boiler has detected an internal sensor failure affecting the hot water supply, meaning it cannot accurately tell if the water is hot enough to use.

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

Thermistor sanitary bypassed.

Engineer required

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

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