BoilerFaultCodesYour boiler has likely stopped working because there is an issue with water not circulating properly, often caused by trapped air or a blockage.
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 boiler detects that water is not moving through the system quickly enough to carry heat away from the burner. The most common reasons are a build-up of air bubbles creating a blockage, or a pump that has failed and can no longer push the water around your radiators.
This issue frequently appears in autumn when heating systems are turned back on after being idle all summer, which often causes internal pump parts to seize.
DIY fix possible
Check that your boiler pressure is between 1 and 1.5 bar on the gauge.Try bleeding your radiators to remove any trapped air from the system.Ensure all radiator valves and isolation valves under the boiler are fully open.Reset the boiler by pressing the 'Reset' button.
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A boiler cover plan would cover faults like 105 — 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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