8A-46 High
Your boiler has detected that the water inside it is too cold and has switched itself off to prevent internal pipes from freezing and bursting.
Technical description: Freeze protection – the boiler won’t operate if flow temperature sensor reads a value that is less than 1°c
Typical repair cost: £0-120 (including labour)
DIY fix possible
Check that your home heating is turned on and the thermostat is set to a calling temperature.Gently warm the room where the boiler is located using an electric heater to raise the ambient temperature.Verify that your condensate pipe (the plastic pipe leading outside) isn't frozen, and thaw it with warm water if necessary.Reset the boiler once the area is warmer and flow has been restored.
Protect yourself from future repair bills
A boiler cover plan would cover faults like 8A-46 — no call-out fees, no surprises.
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Parts commonly replaced
- Flow temperature sensor (NTC)
- Trace heating cable (if installed)
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