Medium
09 on Chaffoteaux Calydra 24 Green

Your boiler's hot water sensor has failed, which means the system cannot accurately measure the water temperature for your taps.

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

Domestic Hot Water thermistor faulty (open circuit)

Engineer required

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

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