BoilerFaultCodesWhat the manual says
Manufacturer manualInverter Error
What causes this fault?
This fault occurs when the main control board loses its connection with the inverter drive that powers the compressor. It is usually caused by an electrical failure within the inverter’s circuitry or a loose connection in the wiring harness that carries signals between the components. Without this communication, the system cannot safely regulate the speed of the motor, so it shuts down to prevent damage.
This fault can be more frequent during summer heatwaves or extreme winter cold, as the inverter components are sensitive to temperature extremes while working under high demand.
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 C7: no call-out fees, no surprise bills.
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