BoilerFaultCodesTechnical description
The safety devices have been activated (lockout)
What causes this fault?
This fault occurs when the boiler's internal safety sensors detect that the system is getting dangerously hot or that water isn't moving through the unit correctly. The most common reasons are a failed pump that isn't circulating water or a faulty limit thermostat that is incorrectly reporting a high temperature.
This issue often surfaces when the heating is first turned on in autumn, as pumps can seize up after being inactive throughout the summer.
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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