BoilerFaultCodesTechnical description
frost protection active (Priority 4)
What causes this fault?
This occurs when the boiler's internal sensors detect that the water temperature has dropped below 5°C. To protect itself from damage, the boiler automatically fires the burner to circulate warm water until the internal temperature reaches a safe level. This is a normal safety function rather than a mechanical failure.
This code is almost exclusively seen during the winter months when external temperatures drop low enough to affect the pipework inside the boiler.
DIY fix possible
Ensure your thermostat is turned up to a normal room temperatureCheck that any radiator valves in cold rooms are openWait for the boiler to finish the cycle; it will clear automatically once the internal temperature rises
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