BoilerFaultCodesYour boiler is performing a routine check of its internal pump and may temporarily pause normal operation while it completes the test.
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 test – checking the basic pump
What causes this fault?
This occurs when the boiler performs a scheduled diagnostic check to ensure the internal pump is spinning freely and moving water correctly. It is a standard safety routine rather than a breakdown, though it can sometimes trigger if the pump is struggling to start due to internal wear or a buildup of debris. Under normal conditions, the code will disappear automatically once the test is successfully completed.
This is more frequent after long periods of inactivity, such as the first time the heating is turned on in autumn, as pumps can occasionally stiffen when not in use.
DIY fix possible
Wait for several minutes as the code usually disappears automatically once the test is finishedMonitor the boiler to ensure it returns to its normal temperature displayIf the code persists for over an hour, try a simple reset using the 'Reset' button
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