BoilerFaultCodesTechnical description
The safety devices have been activated (lockout)
What causes this fault?
This fault occurs when the boiler's internal safety checks detect a major communication failure or a critical error within the electronic control system. It is usually triggered when the main circuit board can no longer safely manage the heating process, causing the unit to shut down instantly to prevent damage. The most common reasons are a malfunctioning main PCB or a fault in the wiring harness that connects the boiler's various sensors.
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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