High
A7 on Worcester Bosch 24 RSF

Your boiler's temperature sensor for hot water has stopped working correctly, meaning your taps might not get hot.

Reviewed by the BoilerFaultCodes Editorial Team · Last reviewed

Call an engineer soon

Book a Gas Safe engineer within 24 to 48 hours. Your boiler may be unsafe or could break down completely if left.

Technical description

The hot water negative thermistor coefficient (NTC) sensor is defective – the hot water sensor or connecting leads need checking.

Engineer required

This is a high severity fault. Stop using the boiler and call a Gas Safe registered engineer. Do not attempt gas-related repairs yourself.

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Related fault codes

A8View →B1View →

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