High Lockout
E4 on Remeha Quinta Ace 25

Your boiler's electronic brain has encountered an internal software or hardware glitch and has stopped 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

Internal control box error

What causes this fault?

This fault occurs when the boiler's internal computer chips fail to communicate correctly with each other or experience a permanent memory error. It is usually caused by wear and tear on the electrical components over time or a sudden electrical surge that damages the delicate circuitry on the main control board.

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

E0View →E1View →E2View →E3View →

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