BoilerFaultCodesYour boiler has become too hot and has automatically shut down for safety purposes.
Book a Gas Safe engineer within 24–48 hours. Your boiler may be unsafe or could break down completely if left.
Technical description: Overheat cut off device tripped or thermostat, overheat cut off device faulty
What causes this fault?
This fault occurs when the water inside your boiler reaches an unsafe temperature, triggering a safety switch to cut the power. It is often caused by a failing pump that can no longer move heat away from the boiler quickly enough or a buildup of limescale and sludge that restricts water flow. In some cases, the safety sensor itself may have developed a fault and is wrongly reporting that the unit is overheating.
This issue often surfaces when you first turn your heating back on in autumn, as circulation pumps can seize up after being idle throughout the summer.
DIY fix possible
Ensure all radiator valves are fully open to allow water flowLocate the reset button or switch on the boiler control panelPress the reset button once; if the light returns immediately, do not attempt further resets
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 Neon 2 lit (No) — no call-out fees, no surprises.
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