Medium
20 on Baxi 624 Combi

Your boiler's internal temperature sensor for the heating system has developed a fault, meaning the unit cannot safely monitor how hot the water is getting.

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

Central heating NTC fault

From this model's manual
Verified against the Baxi 624 Combi 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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