BoilerFaultCodesYour boiler has stopped working because it cannot detect water moving through the system to heat your radiators.
Book a Gas Safe engineer within 24–48 hours. Your boiler may be unsafe or could break down completely if left.
Technical description: Central heating flow switch is open
What causes this fault?
This fault occurs when the boiler's internal sensors cannot confirm that water is physically moving through your heating pipes. The most common reason is a failed pump that isn't pushing water around, or a blockage caused by a build-up of debris or air pockets within the system.
This issue often appears in autumn when the heating is turned on for the first time after summer, as the internal pump can seize up during long periods of inactivity.
DIY fix possible
Check that your boiler pressure gauge is between 1.0 and 1.5 barEnsure all radiator valves and isolation valves under the boiler are fully openGently bleed your radiators to remove any trapped air pocketsReset the boiler using the reset button
Find a Gas Safe engineer
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A boiler cover plan would cover faults like 141 — no call-out fees, no surprises.
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Could it be time for a new boiler?
If repair costs are adding up, a new energy-efficient boiler could be the smarter long-term choice.
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