High Lockout
Neon 1 NOT lit on Glow-worm Space Saver Compleheat 30 40 50

Your boiler has lost power or has insufficient water pressure to operate, meaning it cannot provide heating or hot water.

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

Fault with main supply, PCB fuse or low water pressure switch.

What causes this fault?

This fault occurs when the boiler's control system fails to detect either electrical power or sufficient water pressure to safely ignite. The most common reasons are a blown internal fuse on the circuit board or a leak in the system that has caused the pressure to drop below the minimum required level.

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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