Technical description
Flashing lamp, alone or simultaneously with another lamp (no ignition signal from the full sequence ignition device).
What causes this fault?
This fault occurs when the boiler's control system attempts to light the burner but fails to detect a stable flame after several attempts. The most common reasons are a lack of gas reaching the unit, worn-out spark electrodes that can no longer create an ignition, or a faulty internal component failing to send the 'start' signal.
This fault is more common during the first cold snap of autumn when internal components that have been idle over summer seize up or fail upon restart.
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.