I have a cold water header tank in my loft which feeds the hot water cylinder tank in my bathroom.
My concern is with regard to the cold water tank and pipes in the loft freezing up.
I have heard that, when the weather is freezing, that it is a good idea to open the loft hatch and allow warm air from the house to enter the loft.
I was wondering also if it is a good idea to minimise using the hot water taps. By not using them, you are not using any of the water from the hot water tank in the bathroom which obvioulsy means that it will not want feeding with water from the header tank in the loft.
In simple terms, I mean the water in the loft tank will be water which is not cold and fresh from outside - it will have been inside your house for a few days and will surley be warmer than that from outside and by not allowing fresh cold water to enter the tank, this might contribute to keeping things from freezing up.