Back in the 70s & 80s, when I had a hot water system installed on my roof, I could melt it off, by forcing the HX pumps to run, pumping hot water up to the roof..But, if it was too deep, the end result was a tank of lukewarm water at sunset.
A big problem here in the Boston area, is we get warmth from the Atlantic and polar vortex air from up north.
That causes black-ice on the roads and layers of ice and snow on the roofs.
A few layers of ice inside the snow, isn't a big deal, until roofs start collapsing, then you have to climb up there and shovel it by hand.. Too Dangerous!
Had I known the difficulty of panel cleaning, with layers of ice and snow, I would have never installed that hot water system.
After a few years of repairing that system, when the double-wall HX started leaking, I was very happy to rip out the whole system..
