BoilerFaultCodesYour boiler is overheating because the water inside it is getting too hot too quickly, causing the system to shut down for safety.
Book a Gas Safe engineer within 24–48 hours. Your boiler may be unsafe or could break down completely if left.
Technical description: Temperature of safety sensor is rising too fast.
What causes this fault?
This fault occurs when the water inside the boiler heats up much faster than it can be moved away, leading to a sudden temperature spike that triggers a safety shutdown. The most common cause is a blockage or a failing pump preventing the water from circulating properly through your radiators. It can also be caused by a buildup of sludge or debris inside the heat exchanger, which restricts the flow of water.
This issue often surfaces in autumn when the heating is turned on for the first time after summer, as circulation pumps can seize or stick during long periods of inactivity.
DIY fix possible
Check that your radiator valves and TRVs are fully openEnsure the boiler pressure is between 1 and 1.5 bar on the gaugeGently bleed your radiators to remove any trapped air
Find a Gas Safe engineer
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A boiler cover plan would cover faults like 2P — no call-out fees, no surprises.
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Ideal Maximiser SE is discontinued — time for a new one?
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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