Your boiler's internal computer has encountered an error and is unable to communicate properly with the rest of the system.

Control box fault

What causes this fault?

This fault occurs when the boiler's main control board experiences an internal electronic failure or a loss of data. It is often caused by a component failure on the circuit board itself or a loose connection in the internal wiring preventing the computer from sending instructions to the burner. In some cases, an external power surge or moisture ingress can also damage the sensitive electronics inside.