BoilerFaultCodesTechnical description
Check service mode switch is in minimum position
What causes this fault?
This fault occurs because the internal manual control wheel, often used by engineers during a service to test the system, has been left in a specific test position rather than the 'run' position. Because the boiler thinks it is still being manually tested for performance, it will not respond to your normal thermostat or hot water requests. It is essentially stuck in a maintenance mode that disables its automatic functions.
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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