High
A7 on Worcester Bosch Greenstar R29 40 HE

Your boiler is struggling to accurately measure the temperature of the water it is heating, which means you will likely have no hot water until it is fixed.

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

Hot water NTC sensor defective. Check hot water NTC sensor and connecting lead.

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 →E9View →

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