Strictly speaking, to ‘crank’ a handle is to turn it, often with the connotation that you’re increasing whatever the handle governs, whether it’s water pressure, or — in this case — the heat of the water.
So the idea being given here is that the management of the building has some kind of handle that governs the temperature of the water, and they’ve cranked it a lot, so that the water is really hot. That’s all the phrase is saying, that they’ve turned up the temperature really high.
Of course, they probably don’t have an actual handle with ‘hot’ at one end and ‘cold’ at the other; someone with experience in plumbing could probably tell you what it really is.
As to ‘cranking something up’, it is generally used in the context of increasing the sound something is making, generally a speaker. Of course, speakers don’t have handles that you would literally crank; they generally have dials that you would turn.
But the meaning is the same; it just means ‘increase’. Hope that helps!