BoilerFaultCodesYour boiler has detected that there is not enough water circulating through the system or that the water is heating up too quickly.
This fault should be looked at by a Gas Safe engineer within the next week or two. It may get worse if left.
Technical description: This code can appear if the unit adjusts itself to the small amount of water in the installation.
What causes this fault?
This fault occurs when the boiler senses that the water inside the unit is heating up much faster than expected, which usually points to a lack of flow. This is most commonly caused by low system pressure, a blockage in the pipes, or a failing pump that isn't pushing the water around your radiators effectively. The boiler shuts down as a safety measure to prevent the heat exchanger from overheating.
This issue is frequently seen in autumn when heating systems are turned back on after being idle all summer, which can cause internal pump components to seize.
DIY fix possible
Check the pressure gauge on the front of the boilerIf the pressure is below 1 bar, use the filling loop to top it up to 1.5 barEnsure all radiator valves are fully open to allow water to flow freelyPress the reset button to clear the fault code
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A boiler cover plan would cover faults like 2F — no call-out fees, no surprises.
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