Technical description
Software error
What causes this fault?
This fault occurs when the boiler's internal computer brain fails to process data correctly or loses communication with its sensors. The most common reason is an electrical glitch or a component failure on the main circuit board, which causes the system to shut down for safety. In some cases, loose or damaged wiring between the components can also trigger this software conflict.
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.
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