BoilerFaultCodesWhat the manual says
Manufacturer manualFlame detected even though the appliance is switched off – check the electrode assembly is dry and the pcb and flue are clear.
What causes this fault?
This fault occurs when the boiler's control system detects an electrical current that signals a flame is present, even though the gas should be turned off. This is often caused by moisture on the internal sensors or a failing circuit board that is misinterpreting signals. Essentially, the boiler enters a safety mode because it cannot guarantee it is safe to ignite the gas.
This issue can occasionally follow heavy wind or rain, as moisture driven into the flue can dampen the internal electrodes and trigger a false reading.
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 F7: no call-out fees, no surprise bills.
Affiliate links. We may earn a commission at no extra cost to you.