BoilerFaultCodesTechnical description
No water flow
What causes this fault?
This fault occurs when the boiler's internal sensors detect that water isn't moving through the unit quickly enough to safely carry heat away. The most common reason is a failed circulation pump or a blockage in the central heating pipes, such as built-up sludge or a closed valve. Because the water stays still, it would overheat the heat exchanger, so the boiler shuts down as a safety precaution.
This issue is more frequent in autumn when the heating is turned back on after a long summer break, as internal pump parts can seize up from lack of use.
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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