BoilerFaultCodesTechnical description
No water flow (rate of rise too high)
What causes this fault?
This fault occurs when the heat exchanger gets too hot too quickly because water isn't circulating through the boiler at the required speed. The most common reasons are a failed internal pump, a physical blockage in the pipework, or air trapped within the system preventing the flow of water.
This issue often appears when the heating is first turned on after summer, as internal pump components can seize up 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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