Your boiler is struggling to spark or light the gas correctly, which is a safety mechanism preventing it from trying to ignite for too long.

Maximum ignition time

What causes this fault?

This fault occurs when the boiler's internal safety system detects that the gas has failed to ignite within the safe time limit allowed. The most common reasons are that the spark electrode is too worn to create a flame, or the gas valve isn't opening correctly to let fuel into the burner. In some cases, it can also be caused by a blockage in the flue or a fault in the main control board failing to send the ignition signal.