BoilerFaultCodesTechnical description
Stepper motor fault
What causes this fault?
This fault occurs when the boiler's control board sends a signal to move the gas valve, but it receives no response or detects that the motor is stuck. The most common reason is that the internal components of the gas valve have seized through age or electrical failure, meaning the boiler cannot safely regulate the flow of fuel to the burner.
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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