Medium
10 on Chaffoteaux Calydra 23 Green

Your boiler's hot water sensor has failed, meaning it cannot accurately measure or deliver hot water to your taps.

Reviewed by the BoilerFaultCodes Editorial Team · Last reviewed

Book a service

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

What the manual says

Manufacturer manual

Domestic Hot Water thermistor faulty (short circuit)

From this model's manual
Verified against the Chaffoteaux Calydra 23 Green installation & service manual, page 17.
Plain-English guidance below. Severity, DIY steps, costs and parts are our interpretation to help you act, not text from the manual.

Engineer required

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

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