BoilerFaultCodesYour boiler has detected that the temperature is very low and has automatically turned itself on to prevent the internal pipes from freezing.
This is a minor fault. Keep an eye on it and mention it at your next annual boiler service. Reset the boiler and see if it clears.
Technical description: Boiler is active for boiler frost protection.
What causes this fault?
This occurs when the sensors inside the boiler detect the water temperature has dropped below 5°C. To protect the internal components from freezing and potential cracking, the boiler automatically fires up to circulate warm water until it reaches a safe temperature. It is a protective measure rather than a failure of a part.
This code is almost exclusively seen during winter or periods of extreme cold when the ambient temperature around the boiler drops significantly.
DIY fix possible
No action is required as this is a normal automated safety feature.The code will disappear once the boiler reaches a safe internal temperature.Ensure your external condensate pipe is not frozen if the weather is extremely cold.
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A boiler cover plan would cover faults like FP — no call-out fees, no surprises.
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