Shutting of Hot Water Rads

[monkeyland]

I would like to shut off the heat to my 3rd floor which is an apartment I now want to keep vacant and don't want the expense of heating 800 square feet for nothing. First, can I successfully do this using the intake valve? What are the other considerations? Does the water in the supply pipes to these rads then remain cool or will the circulating pump send hot water thru them up to the intake valve but not beyond? If the supply pipes are in an unheated crawl space (the third floor is a finished attic with sloping ceilings and knee walls) do I then need to be concerned with freezing? Any advice to educate me would be helpful. I am new to hot water heating.

 

[cross thread]

FIT THERMOSTATIC VALVES THEY HAVE A FROST SETTING ,SO RADS ONLY COME ON WHEN NEEDED

 

[JohnD]

Canadian winters get very much colder than we are used to here, you might do better to take advice from someone local (this is a UK website and in recent years we have had relatively few frozen pipes).