Technical description
Internal fault (PCB)
What causes this fault?
This fault occurs when the boiler's internal computer experiences a critical communication breakdown or a physical component failure on the circuitry. It is often caused by an electrical surge, moisture getting onto the board, or simply the natural degradation of the solder joints and microchips over time.
This fault is slightly more common during the winter months, as the increased workload on the boiler can push an aging or stressed circuit board to the point of total failure.
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.