Medium
E321 on Baxi Netaheat

Your boiler's hot water sensor has detected an electrical fault or an unusual temperature reading, meaning your taps may not get as hot as they should.

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.

Technical description

Hot water negative temperature coefficient (NTC) fault.

Engineer required

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

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Related fault codes

E10View →E110View →E133View →

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