BoilerFaultCodesTechnical description
Flow sensor fault / high limit intervention
What causes this fault?
This fault occurs when the boiler's internal temperature gets too high or the sensor tasked with monitoring that heat fails. The most common reasons are a lack of water flow through the system due to a pump failure, a blockage in the heat exchanger, or a faulty safety sensor providing an incorrect reading.
This issue often appears when the heating is first turned on after summer, as internal components like the pump can seize during long periods of inactivity.
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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