BoilerFaultCodesTechnical description
Error during start-up procedure (requires 3 minute venting cycle after resolution)
What causes this fault?
This fault occurs when the boiler tries to light the burner but fails to detect a consistent flame. The most common reasons are a worn-out ignition spark that can no longer light the gas, or a dirty sensor that cannot tell the boiler the flame is safely lit. In some cases, it may also be caused by an insufficient gas supply or a faulty internal valve.
This fault is more frequent during the first cold snap of winter, as internal components that have been idle over summer may struggle to operate correctly when first under heavy load.
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.