BoilerFaultCodesYour boiler is performing a routine check of the internal pump to ensure water is flowing correctly before it starts the main heating process.
This is a minor fault. Keep an eye on it and mention it at your next annual boiler service. Reset the boiler and see if it clears.
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.
Find a Gas Safe engineer
Search the official register for a qualified engineer in your area.
Gas Safe Register →Protect yourself from future repair bills
A boiler cover plan would cover faults like S.22 — no call-out fees, no surprises.
Affiliate links — we may earn a commission at no extra cost to you.
Glow-worm Ultracom 24cx 30cx is discontinued — time for a new one?
Parts for discontinued models can be hard to find and expensive. A new A-rated boiler could save you money on both repairs and energy bills.
Affiliate links — we may earn a commission at no extra cost to you.