BoilerFaultCodesTechnical description
Status indicator during start-up/heat demand sequence
What causes this fault?
This code appears when the boiler is running a brief pre-check to ensure there is sufficient water pressure and flow before the main burner ignites. It is caused by the internal pump building up pressure to confirm the system is safe to operate. If this code stays on the screen for a long time, it could indicate that air is trapped in the system or the pump is struggling to move water effectively.
DIY fix possible
Check that your radiator valves are openEnsure the boiler pressure is between 1.0 and 1.5 barWait a few minutes to see if the code changes to a normal heating mode
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