BoilerFaultCodesYour boiler has sensed that it is getting too hot and has automatically 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: Safety temperature limiter in central heating (CH) flow has tripped the system pressure or safety temperature limiter needs checking
What causes this fault?
This fault occurs when the water inside the boiler reaches an unsafe temperature, triggering a safety switch to kill the power. The most common reasons are a pump failure that stops water from moving around the system or a build-up of debris causing a blockage in the heat exchanger.
This fault is more common in autumn when the heating is turned back on after a long break, as circulation pumps can often seize up from lack of use.
DIY fix possible
Check that your system pressure is between 1 and 1.5 bar on the front gaugeTop up the water pressure using the white internal or external filling loop if it is too lowEnsure all radiator valves are fully open and there are no blockagesPress the 'reset' button on the boiler control panel once pressure is corrected
Find a Gas Safe engineer
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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 CDi Classic 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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