High Lockout
Green LED On, Red LED Off on Vokera Compact HE

Your boiler has lost water pressure and has shut itself down as a safety precaution to prevent damage.

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

Low/zero pressure

What causes this fault?

This fault occurs when the water pressure inside your heating system drops below a safe operating level. The most common reasons are a slow leak from a radiator valve or pipework, or the air pressure inside the internal expansion vessel needing to be topped up by an engineer.

This issue is more frequent in autumn when the heating is turned back on after summer, as the change in temperature can cause weakened seals to leak or air pockets to move through the system.

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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