BoilerFaultCodesTechnical description
The lockout light will be illuminated at the end of the 4 second ignition period and the fan will run on.
What causes this fault?
This fault occurs when the boiler's control system attempts to start the heating process but cannot detect a stable flame. The most common reasons are a lack of spark from a worn ignition lead or the gas valve failing to open and deliver fuel to the burner. Because the boiler cannot confirm the gas has lit safely, it shuts down to prevent any hazards.
This issue is frequently seen during the first cold snap of autumn when internal components like the gas valve can stick after being inactive over the summer months.
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.