High Lockout
e3 on Remeha Avanta Plus 35c

Your boiler has detected an electrical connection issue or an internal fault in its main control computer, causing it to stop working for safety.

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

Control unit or earth fault. Mains supply not correctly earthed. Control unit faulty.

What causes this fault?

This fault occurs when the boiler's main control board loses its vital electrical grounding connection or suffers an internal hardware failure. It is often triggered by loose wiring between components or a power surge that has damaged the delicate circuitry inside the control unit.

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.

Find a Gas Safe engineer
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Related fault codes

E4View →E11View →E31View →

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