BoilerFaultCodesYour boiler has become 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: Overheat thermostat operated or faulty
What causes this fault?
This fault occurs when the internal temperature of the boiler rises above a safe limit, triggering a safety sensor to cut the power. The most common reasons are a failed pump that isn't moving water away from the heat exchanger quickly enough, or a buildup of limescale and sludge that restricts water flow.
This fault often appears during the first cold spell of autumn when the heating is turned back on after being idle all summer, which can cause internal pump components to seize.
DIY fix possible
Check that your radiator valves are open and not turned to the off position.Ensure your boiler pressure is between 1 and 1.5 bar on the pressure gauge.Press the 'Reset' button (usually a small 'R' or turn the selector knob to 'R' for 5 seconds) to see if the fault clears.
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A boiler cover plan would cover faults like 110 — no call-out fees, no surprises.
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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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