Technical description
Flame failure has occured. Reset boiler by turning temperature control to Off, waiting 30 seconds and then on.
What causes this fault?
This fault occurs when the boiler's internal safety system cannot detect a flame after several attempts to ignite. The root cause is usually a lack of fuel reaching the burner, a worn-out ignition spark, or a sensor that has become too dirty to 'see' the flame even if it is actually lit.
This issue is more frequent during the first cold snap of winter when components that have sat idle all summer are suddenly forced to operate under high demand.
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.