Technical description
Pump pre run
What causes this fault?
This code appears when the boiler initiates a brief test cycle to ensure the internal pump is moving water through the heat exchanger before the burner ignites. It is a standard safety and performance check to prevent the unit from overheating during the start-up phase. Under normal conditions, this is a routine operation and does not indicate a breakdown.
DIY fix possible
No action is required as this is a normal operational status message, not a fault.Wait approximately 20-60 seconds for the boiler to move to the next stage of ignition.Check that your heating controls or thermostat are calling for heat.