BoilerFaultCodesTechnical description
Flame detected after gas. Gas valve switched off. Cables and connections to gas valve. Condensate trap. Flue (for blockages). Otherwise replace control board.
What causes this fault?
This fault occurs when the boiler's internal sensors continue to detect a flame or electrical current even after the gas valve has been instructed to close. The most common reason is a faulty gas valve that is failing to shut off properly or a 'ghost' signal caused by a malfunctioning control board or dampness around the electrodes. Because the system thinks a fire is still burning when it shouldn't be, it shuts down immediately to ensure your safety.
This fault can occasionally be triggered during periods of heavy rain or high humidity if moisture causes a short circuit in the electrical connections or blockages in the flue.
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.