High Lockout
Display not illuminated on Potterton Envoy 30

Your boiler has no electrical power, meaning the controls and display are completely dead.

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

All power off.

What causes this fault?

This fault occurs when the electrical supply to the boiler's internal brain has been interrupted or a critical component has failed. The most common reason is a blown fuse on the main circuit board or a failure of the internal transformer which converts power for the display. In some cases, it can be caused by an external issue like a tripped circuit breaker or a blown fuse in the wall switch.

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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