BoilerFaultCodesTechnical description
Heating mode frost protection error
What causes this fault?
This fault occurs when the boiler’s internal sensors detect that the water temperature has dropped to a level where there is a genuine risk of the heat exchanger freezing. It typically happens because the boiler is located in a very cold area, such as a garage or outbuilding, or because a faulty sensor is sending an incorrect freezing signal to the control board. When this happens, the boiler pauses operation as a safety measure to prevent the internal pipework from cracking.
This fault is almost exclusively seen during the winter months when external temperatures drop near or below freezing.
DIY fix possible
Check that the room thermostat is turned up to call for heatEnsure any radiator valves in the room with the thermostat are fully openWait 15-30 minutes for the boiler to automatically clear the status once it detects a safe temperature riseGently increase the property temperature to thaw the surrounding air