BoilerFaultCodesYour boiler has sensed a flame when there shouldn't be one, or the sensor that monitors the fire is sending a confusing signal to the control board.
Book a Gas Safe engineer within 24–48 hours. Your boiler may be unsafe or could break down completely if left.
Technical description: Flame detection fault
What causes this fault?
This fault occurs when the boiler's control board detects an electrical signal suggesting a flame is present even when the gas should be turned off. The most common reason is a faulty sensing electrode that has became damp or coated in carbon, though it can also be caused by a leaking gas valve or a glitch in the main circuit board.
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 F27 — no call-out fees, no surprises.
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