BoilerFaultCodesYour boiler has got too hot and has shut itself down as a safety precaution 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 thermostat (overheat)
What causes this fault?
This fault occurs when the water inside the boiler exceeds a safe temperature, triggering a safety switch to cut power. The most common reasons are a pump failure preventing heat from moving away from the boiler, or a blockage such as 'sludge' in the pipework obstructing flow.
This fault often appears during the first few cold days of autumn when a heating system is turned back on after being idle all summer, which can cause the pump to seize.
DIY fix possible
Check that your radiator valves are open and not turned to offEnsure there is enough water pressure in the system (check the gauge reads between 1 and 1.5 bar)Press and hold the reset button for a few seconds to see if the boiler restarts
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 E02 — no call-out fees, no surprises.
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Ideal Mini HE 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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