BoilerFaultCodesYour boiler has shut down because it has detected it is getting too hot, usually caused by a circulation problem or a blockage.
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 Operated
What causes this fault?
This fault occurs when the internal safety sensors detect that the water inside the boiler has reached an unsafe temperature, triggering an automatic shutdown to prevent damage. The most common reasons are a pump failure that stops water from moving or a buildup of sludge and debris that creates a blockage in the heat exchanger.
This issue often surfaces when the heating is first turned on after summer, as the internal pump can seize up from months of inactivity.
DIY fix possible
Check that your radiator valves are openEnsure there is enough water pressure in the system (usually between 1 and 1.5 bar)Wait for the boiler to cool down and try pressing the reset button
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 E110 — no call-out fees, no surprises.
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Potterton Gold 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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