High
815 W/B on Worcester Bosch Junior 28i

Your boiler's internal temperature sensors are giving conflicting or incorrect readings, causing the system to stop working to prevent damage.

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

Low loss header temperature sensor faulty – check the sensor port or check the differential sensor for incorrect installation position or breakage

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

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