Technical description
Flame circuit error - possible control box fault..
What causes this fault?
This fault occurs when the boiler's internal computer is unable to correctly process the electrical signals required to monitor the flame. It is usually caused by a communication failure between the sensing hardware and the main control board, meaning the boiler shuts down because it cannot verify that it is burning gas safely. In many cases, this is due to moisture on the electronics or a component failure within the circuit board itself.
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.