High Lockout
E31 on Remeha Avanta Plus 35c

Your boiler has detected a problem with the sensor that measures hot water temperature, which often means your hot water may be cold or inconsistent.

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

DHW temperature sensor error (S3)

What causes this fault?

This fault occurs when the boiler's control board loses communication with the sensor responsible for monitoring your hot water temperature. The most common reason is that the internal components of the sensor have failed due to age, or the electrical connection has become loose or corroded. Because the boiler can no longer tell how hot the water is, it shuts down as a safety precaution 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

E3View →E32View →E37View →

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