BoilerFaultCodesYour boiler has detected a mechanical issue with the part that controls the flow of gas, preventing it from lighting safely.
Book a Gas Safe engineer within 24–48 hours. Your boiler may be unsafe or could break down completely if left.
Technical description: Gas valve stepping motor fault.
What causes this fault?
This fault occurs when the boiler's control board loses communication with the small motor that regulates gas flow into the burner. The most common reason is that the motor inside the gas valve has physically seized or suffered an electrical failure, meaning it can no longer open to let fuel through. Occasionally, a loose connection or moisture on the wiring harness can also prevent the signal from reaching the valve.
Engineer required
This fault requires a Gas Safe registered engineer. Do not attempt gas-related repairs yourself.
Find a Gas Safe engineer
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A boiler cover plan would cover faults like F15 — no call-out fees, no surprises.
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