BoilerFaultCodesTechnical description
Flame signal without flame present – air/gas ratio control valve may need replacing as might the ionisation cable
What causes this fault?
This fault occurs when the boiler's internal sensor detects an electrical signal signifying a flame at a time when the burner should be off. The most common reason is a faulty detection electrode sending a false signal or a gas valve that is leaking slightly, allowing a small amount of fuel to stay lit. Because the boiler cannot safely confirm the fire is out, it shuts down to prevent any risk of overheating or gas build-up.
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.
Find a Gas Safe engineer
Search the official register →