BoilerFaultCodesYour boiler is stopping itself from working because the water temperature inside is getting too hot, similar to a car engine overheating.
Book a Gas Safe engineer within 24–48 hours. Your boiler may be unsafe or could break down completely if left.
Technical description: Condensing Temperature High
What causes this fault?
This fault occurs when the water temperature within the heat exchanger rises too quickly or exceeds safe limits, causing the boiler to shut down to prevent damage. The most common reason is a lack of water flow, often caused by a failing pump or a blockage in the system pipes that prevents heat from being carried away from the unit.
This fault is frequently seen at the start of autumn when heating systems are turned back on after a summer of inactivity, which can cause internal pump components to seize.
DIY fix possible
Check that all radiator valves are fully open to allow water to circulate.Ensure the external magnetic lime-scale filter (if fitted) is not blocked.Restart the boiler using the reset button to see if the fault clears.
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A boiler cover plan would cover faults like Pd — 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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