BoilerFaultCodesYour boiler is struggling to move water around the system correctly, which is likely caused by trapped air or a failing pump.
Book a Gas Safe engineer within 24–48 hours. Your boiler may be unsafe or could break down completely if left.
Technical description: Primary circulation fault (no blockage)
What causes this fault?
This fault occurs when the boiler detects that water isn't flowing through the internal heat exchanger at the required speed, causing a rapid rise in temperature. The most common reasons are air bubbles trapped within the pump or a mechanical failure of the pump motor which prevents it from pushing water around your radiators. It can also happen if the system pressure is too low or if an internal valve has become stuck.
This issue is more frequent in autumn when heating systems are turned back on after being idle all summer, which often causes pump components to seize or air pockets to shift.
DIY fix possible
Check that your radiator valves are fully openGently bleed your radiators to remove any trapped airEnsure the system pressure is between 1.0 and 1.5 bar on the gauge
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A boiler cover plan would cover faults like 193 — no call-out fees, no surprises.
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Parts for discontinued models can be hard to find and expensive. A new A-rated boiler could save you money on both repairs and energy bills.
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