BoilerFaultCodesYour boiler has detected that there is not enough water circulating through the system or there is an air lock preventing flow.
Book a Gas Safe engineer within 24–48 hours. Your boiler may be unsafe or could break down completely if left.
Technical description: All Boilers
What causes this fault?
This fault occurs when the internal sensors detect that water isn't moving through the heat exchanger quickly enough to safely carry heat away. The most common reasons are a seized or failing circulation pump, a build-up of air bubbles creating a blockage, or debris in the system pipework restricting the flow.
This issue is frequently seen in autumn when heating is turned on for the first time after summer, as pumps can seize during long periods of inactivity.
DIY fix possible
Check the pressure gauge on the front of the boiler; it should be between 1 and 1.5 bar.If the pressure is low, use the filling loop underneath the boiler to top it up.Bleed your radiators to remove any trapped air that might be blocking water flow.
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