BoilerFaultCodesYour boiler has stopped working because it cannot detect the necessary change in water pressure required to safely start the heating process.
Book a Gas Safe engineer within 24–48 hours. Your boiler may be unsafe or could break down completely if left.
Technical description: Pump / Water pressure sensor fault (No pressure change detected when pump starts)
What causes this fault?
This fault occurs when the boiler's computer fails to see a slight jump in water pressure when the internal pump tries to kick in. The most common reasons are either a buildup of debris blocking the pressure sensor or the pump itself failing to spin, meaning the system can't prove there is enough water flow to operate safely.
This issue often surfaces in autumn when the heating is turned on for the first time after summer, as the pump can seize up from several months of inactivity.
DIY fix possible
Check the central heating pressure gauge; if it is below 1.0 bar, top it up to 1.5 bar using the filling loop.Ensure all radiator valves are open and not blocked.Restart the boiler to see if the pump clears any temporary air locks.
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