BoilerFaultCodesYour boiler is struggling to move water because there is air trapped in the system or the water pressure has dropped too low.
Book a Gas Safe engineer within 24–48 hours. Your boiler may be unsafe or could break down completely if left.
Technical description: Controlled characteristic pump has run dry
What causes this fault?
This fault occurs when the boiler detects that there is no water passing through the internal pump, causing it to spin without resistance. The most common reasons are a significant drop in system pressure or a large pocket of air becoming trapped inside the pump itself, which prevents it from being able to circulate heat. To protect the internal components from overheating or burning out, the boiler triggers a safety shutdown.
This issue is frequently seen in autumn when heating systems are turned back on after the summer, as air often settles in the pump or radiators during periods of inactivity.
DIY fix possible
Check the pressure gauge and top up the system to 1.5 bar using the filling linkGently bleed air from your radiators using a radiator keyPress the reset button on the boiler control panel
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A boiler cover plan would cover faults like A1 — 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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