BoilerFaultCodesTechnical description
Pre-Circulation Fault
What causes this fault?
This fault occurs when the boiler's internal sensors detect that water isn't moving through the unit quickly enough during its initial checks. This is usually caused by a large pocket of air trapped inside the pipework or a failing pump that no longer has the power to push water around the system. In some cases, a build-up of sludge or debris can also create a physical blockage that restricts the flow.
This issue is more frequent in autumn when the heating is turned back on after a long summer break, as pumps can seize and air can settle in the pipes during 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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