High Lockout
é0 on Remeha Avanta Plus 35c

Your boiler has detected a problem with its internal temperature sensors, meaning it cannot accurately monitor the water temperature and has shut down as a safety precaution.

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

Flow or return sensor fault. Short circuit in the flow, return or boiler temperature sensor. Defective or not (properly) connected flow, return or boiler temperature sensor.

What causes this fault?

This fault occurs when the boiler's internal computer loses communication with the sensors that monitor water temperature. It is usually caused by an electrical failure within the sensor itself or a loose connection in the wiring, preventing the boiler from knowing if it is safe to continue heating.

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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