BoilerFaultCodesTechnical description
Circulation Fault (Primary Circuit)
What causes this fault?
This fault occurs when the water inside the boiler gets too hot too quickly because it isn't being pumped away effectively. The most common reasons are a seized internal pump, a physical blockage in the pipework, or air trapped within the system preventing proper flow. It can also be triggered if there isn't enough water pressure to allow the circulation to take place.
This fault is more frequent in autumn when heating systems are first turned on after being idle all summer, which can cause the internal pump to seize.
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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