BoilerFaultCodesYour boiler has developed a problem with a motor that controls the gas flow, meaning it cannot ignite safely to provide heat or hot water.
Book a Gas Safe engineer within 24–48 hours. Your boiler may be unsafe or could break down completely if left.
Technical description: Stepper motor fault
What causes this fault?
This fault occurs when the small internal motor that regulates the flow of gas into the burner fails to move into the correct position. The most common reason is that the motor's internal components have worn out or become stuck, preventing the boiler from safely controlling the flame. In some cases, the control board may also be failing to send the correct electrical signals to this motor.
Engineer required
This fault requires a Gas Safe registered engineer. Do not attempt gas-related repairs yourself.
Find a Gas Safe engineer
Search the official register for a qualified engineer in your area.
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A boiler cover plan would cover faults like F15 — no call-out fees, no surprises.
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