On the topic of heating water...
Here in temperate New England, The radiator blind needs to be up at least 3/4 to keep the calorimeter above 190 F. on a typical day. (I picked up a nice industrial calorimeter, and fitted it in place of the broken off original.)
In winter, the blind needs be drawn up tight to get any warmth from her at all. But, when working hard on a white winter's day, the steam leaking out the cap is a pleasant sight.
Needless to say, There is 50/50 glycol mix in the rad. year round. Whenever there is cooling system work done on any of the automobiles, the draining goes to the Fordson supply if not right into the top tank

Keeps the rust down too.
Cheers