BoilerFaultCodesYour heat pump has stopped working because its internal computer board is having trouble communicating with the compressor system.
Book a Gas Safe engineer within 24–48 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 main control board loses its digital connection with the inverter, which is the component responsible for managing the heat pump's power. The most common reason is an internal electronic component failure or a loose connection in the wiring that prevents the system from safely starting the compressor.
Engineer required
This fault requires a Gas Safe registered engineer. Do not attempt gas-related repairs yourself.
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A boiler cover plan would cover faults like L43 — no call-out fees, no surprises.
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Could it be time for a new boiler?
If repair costs are adding up, a new energy-efficient boiler could be the smarter long-term choice.
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