BoilerFaultCodesWhat the manual says
Manufacturer manualSafety switch-off: Flame simulation - Monitoring electrode reports an incorrect flame
What causes this fault?
This fault occurs when the boiler's internal sensors detect a flame after the burner should have switched off, or even before it has started. The most common reason is a faulty sensing electrode sending a false signal, but it can also be caused by a leaking gas valve or moisture on the control board electronics.
This fault can be more common during periods of high humidity or heavy rain, as moisture entering the flue or building up inside the casing can interfere with the sensitive electrical signals.
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.
Avoid the next call-out bill
A cover plan would handle faults like F.27: no call-out fees, no surprise bills.
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