BoilerFaultCodesYour boiler has safety-tripped because it has detected an overheating issue within the internal system.
Book a Gas Safe engineer within 24–48 hours. Your boiler may be unsafe or could break down completely if left.
Technical description: Burner & Fault Indicator Neon
What causes this fault?
This fault occurs when the internal water temperature exceeds a safe limit, causing the overheat thermostat to shut the system down to prevent damage. The most common reasons are a pump failure that stops water from moving or a blockage within the main heat exchanger that restricts flow. It can also be triggered by trapped air in the pipework or a faulty sensor providing an incorrect temperature reading.
This fault is more common in autumn when heating systems are first turned on after being idle all summer, as stagnant water can cause the pump to seize or stick.
DIY fix possible
Check that your home's radiator valves are fully open.Ensure there is enough water pressure in the system (typically between 1 and 1.5 bar).Turn the control knob to the 'Reset' position, hold for five seconds, and release.
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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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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