Technical description
If the reset neon lights, turn the boiler temperature control to '0' (off), wait 30 seconds, then repeat the lighting instructions.
What causes this fault?
This fault occurs when the boiler's internal safety sensors detect that the unit has become too hot or has failed to light correctly. The most common reasons are a temporary interruption in the gas supply, a build-up of internal heat due to a pump failure, or a worn-out component that can no longer detect the flame.
This issue often surfaces during the first cold spell of autumn when the boiler is pushed to work harder after sitting idle throughout the summer.
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.