BoilerFaultCodesTechnical description
Circulation Fault (Primary Circuit)
What causes this fault?
This fault occurs when water is unable to circulate through your boiler's internal pipework fast enough, leading to a rapid rise in temperature. The most common reason is a failing pump that can no longer push the water, though a blockage caused by a build-up of sludge or a stuck internal valve can also restrict the flow. To prevent internal damage from overheating, the boiler safety system shuts the unit down completely.
This fault is more common in autumn and winter when the heating is first switched back on after several months of inactivity, as pumps can seize during long periods of disuse.
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.