BoilerFaultCodesYour boiler has shut down because its internal temperature got too hot and a safety switch has tripped to prevent damage.
Book a Gas Safe engineer within 24–48 hours. Your boiler may be unsafe or could break down completely if left.
Technical description: Safety temperature limiter has operated
What causes this fault?
This fault occurs when the water inside the boiler exceeds a safe temperature, causing a safety sensor to cut the power. It is usually caused by a pump failure that stops water from moving or a blockage in the heat exchanger that traps heat inside the unit.
This issue often surfaces when the heating is first turned on in autumn, as pump components can seize up after being inactive over the summer months.
DIY fix possible
Check that your boiler pressure is between 1 and 1.5 bar on the pressure gaugeEnsure all radiator valves are fully open to allow water to flowPress and hold the reset button for five seconds once the boiler has cooled down
Find a Gas Safe engineer
Search the official register for a qualified engineer in your area.
Gas Safe Register →Protect yourself from future repair bills
A boiler cover plan would cover faults like E9 — no call-out fees, no surprises.
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Worcester Bosch RD 532 Combi 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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