BoilerFaultCodesYour boiler has detected a signal error between its control system and gas supply, 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: No demand to gas valve | Cause: Electronic board defective, Gas valve defective
What causes this fault?
This fault occurs when the boiler's internal computer detects a flame signal at a time when there shouldn't be one, or if the sensors are providing conflicting information. The most common reason is a communication failure between the electronic control board and the gas valve, causing the system to shut down as a safety precaution. In some cases, moisture or a failing component can trick the boiler into thinking gas is burning when the valve is actually closed.
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 F.27 — no call-out fees, no surprises.
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