BoilerFaultCodesTechnical description
Pre-circulation error
What causes this fault?
This fault occurs when the boiler's internal sensors detect that water isn't moving through the unit quickly enough before it attempts to fire up. The most common reason is a seized or failing circulation pump, though it can also be caused by air trapped in the heat exchanger or a blockage in the system pipework. Because the heat cannot be carried away from the burner, the boiler shuts down to prevent internal damage from overheating.
This error is frequently seen at the start of autumn when heating systems are turned on for the first time after summer, as pump components can seize during long 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.