BoilerFaultCodesYour boiler has switched itself off because it has become too hot internally and needs to cool 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: Boiler overheat tripped
What causes this fault?
This fault occurs when the water inside the boiler reaches an unsafe temperature, triggering a safety switch to prevent damage. It is usually caused by a circulation failure, such as a seized internal pump or a blockage in the system prevents heat from being carried away quickly enough.
This issue often surfaces when the heating is first turned on after summer, as pump components can seize up during long periods of inactivity.
DIY fix possible
Turn the boiler off and allow it to cool for at least 30 minutes.Check that your radiator valves are open and that the system pressure is between 1 and 1.5 bar.Turn the selector switch to the reset position for five seconds and then back to your desired setting.
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 Promax 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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