BoilerFaultCodesTechnical description
Internal control unit error
What causes this fault?
This fault occurs when the boiler's main control board experiences an internal electronic failure or loses the ability to communicate with other sensors. The most common reason is age-related component fatigue on the circuit board, though it can also be triggered by a loose connection in the internal wiring harness. Because the 'brain' of the boiler can no longer guarantee safe operation, it shuts the system down as a precaution.
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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