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 just before the burner ignites. The most common reason is a failing or seized circulation pump, though it can also be triggered by a build-up of sludge or debris blocking the pathways within the heat exchanger.
This fault is frequently seen in autumn when the heating is turned back on for the first time, as pump components can seize up after being idle throughout the summer.
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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