High Lockout
RED NEON on Potterton Powermax HE

Your boiler has shut down completely for safety reasons and will not provide heating or hot water until it is manually reset or repaired.

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

Safety LOCK-OUT condition

What causes this fault?

This fault occurs when the boiler's control system detects a failure in the ignition process or a safety breach, leading to an immediate shutdown. The most common reasons include the burner failing to light, a loss of flame signal during operation, or an internal component like the fan or gas valve not responding correctly. It is a protective measure designed to prevent the boiler from running in an unsafe condition.

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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