BoilerFaultCodesTechnical description
Factory setting
What causes this fault?
This fault occurs when the boiler's internal memory has been wiped or corrupted, meaning the unit has forgotten its specific model and power settings. It is usually caused by a major electrical surge or a failure in the main control board that erases the vital 'Device Specific Number' needed for operation. Without this digital identity, the boiler shuts down as a safety precaution because it no longer knows how to manage its gas and water flow safely.
This fault is more common during winter or stormy weather, as power surges and lightning strikes are more frequent and can damage the boiler's sensitive electronic components.
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.