Your boiler has switched itself off because it has become too hot, usually because water isn't moving through the system properly.
Book a Gas Safe engineer within 24–48 hours. Your boiler may be unsafe or could break down completely if left.
Technical description: Overheat - Normally associated with either poor or lack of primary water circulation. Wait for appliance to cool then re-set as described for code 01.
What causes this fault?
This fault occurs when the water inside the boiler exceeds a safe temperature limit, triggering a safety shutdown to prevent damage. The most common reason is that the internal pump has failed or is blocked, preventing the heat from being carried away to your radiators. It can also be caused by a build-up of limescale in the heat exchanger or air trapped within the system.
This fault is often seen at the start of autumn when the heating is turned back on after being off all summer, which can cause the internal pump to seize.
DIY fix possible
Turn the boiler off and wait at least 30 minutes for it to cool down.Check that your radiator valves are open and your system pressure is between 1 and 1.5 bar.Turn the control knob to the 'Reset' position, hold for a few seconds, then move it back to the 'ON' position.
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