High Lockout
Pump Fault on Ideal Logic Max Heat

Your boiler is unable to circulate water around the system, meaning your heating and hot water will not work.

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

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What causes this fault?

This fault occurs when the boiler's internal pump is unable to move water through the heat exchanger, often due to a mechanical failure or a build-up of debris known as magnetite. It can also be caused by a communication failure where the main control board is unable to send power or signals to the pump motor.

This issue is more frequent in autumn when heating systems are turned back on after a summer of inactivity, which can cause internal pump components to seize.

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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