BoilerFaultCodesWhat the manual says
Manufacturer manualInverter High Temperature
What causes this fault?
This fault occurs when the power electronics that drive the heat pump compressor reach a safety temperature limit. It is usually caused by a failure of the internal cooling fan or a build-up of dust and debris blocking the heatsink, preventing the system from shedding heat effectively. When the electronics cannot stay cool, the unit shuts down to prevent permanent component failure.
This fault is more common during summer heatwaves, as high ambient temperatures make it harder for the unit's internal cooling system to keep the electronics within safe limits.
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.
Avoid the next call-out bill
A cover plan would handle faults like LC9: no call-out fees, no surprise bills.
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