High Lockout
J47 on Ideal HP290

Your heat pump's internal power control system has encountered a fault, meaning the outdoor unit cannot communicate properly with the compressor to 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

Inverter Error

What causes this fault?

This fault occurs when the internal electronics that manage the compressor's power supply fail to regulate the electrical flow correctly. It is usually caused by a technical failure on the inverter circuit board or loose internal connections that prevent the system from getting the energy it needs to run.

This fault can be more frequent during summer or heatwaves, as high ambient temperatures place additional thermal stress on the electronic power components.

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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