High Lockout
Test 2 on Vokera Hydra

Your boiler is unable to move the water around the system, which means it cannot heat your home or provide 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

Pump failure

What causes this fault?

This fault occurs when the boiler's internal pump fails to circulate water, leading to a rapid build-up of heat that the system cannot shed. The most common reasons are a mechanical seizure of the pump motor after a period of inactivity or an electrical failure where the component no longer receives power from the control board.

This issue frequently appears during the first cold snap of autumn when a pump that has been idle all summer fails to spin back up.

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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