Medium
26 on Chaffoteaux Calydra 100

Your boiler has detected that a temperature sensor is not communicating correctly, which may prevent your hot water or heating from working reliably.

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

Thermistor cylinder bypassed

From this model's manual
Verified against the Chaffoteaux Calydra 100 installation & service manual.
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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