High Lockout
é0 on Remeha Avanta 18V

Your boiler has detected a problem with its internal temperature sensors, meaning it cannot accurately tell how hot the water is 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.

What causes this fault?

This fault occurs when the boiler's control board loses communication with the sensors that monitor water temperature. It is usually caused by a sensor element failing due to age or a loose electrical connection in the internal wiring. Because the boiler can no longer confirm it is operating at a safe temperature, it shuts down instantly to prevent overheating.

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

E1View →E2View →E7View →

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