Wrightwood's pics remind me of the time my parents house had a frozen pipe. This on the San Francisco peninsula, about 1990 or so, after a sustained hard freeze of about 4 days.
This was a 1" copper pipe, inside one of the two roof-mounted Solar Hot Water tanks we lovingly called "Coffins" We figured that since the plumbing was under the tank, in the coffin, and on a south-facing roof, it would never be a problem. At that point the coffins had been up on the roof for over 20 years.
They held 50 gallons each, and one of the feed lines had split linearly under one of the tanks, and 100 gallons of water came over the side of the roof, and onto the walk below. My brothers and I came over with 50 lbs of rocksalt, to melt the ice, and one brother who was starting out as a general contractor cut out the split piece, and sweated in a new one. We then covered all the pipes inside and outside the coffins with pipe insulation.
My brand-new girlfriend (at the time) had never met any of my family before that day; now she's watching us on the roof, trying to fix this thing. She has now been my wife for almost 15 years.
Peace