How to get hot water from the tap

For the first two and a half days I lived in Japan, I had no hot water. I didn't know if I needed to turn some switch somewhere (everything is, of course, marked in Japanese) or if some water heater needed to be turned on or fixed somewhere. So, cold showers it was.
When I went into work on Monday (the college owns the apartments), I was able to ask how to get hot water from the tap. For each room (kitchen and shower), there is a small control panel on the wall that looks not unlike a thermostat. I knew my apartment did not have a central heating or cooling system, but I though perhaps they were wired into the strange ac/fan type things that are in the wall. It seems this controller is for the hot tap water for that room. It can be used to adjust the temperature of the hot water and must be turned on for there to be any accessible hot water at all.

The exciting thing about this is, that when you push certain buttons, mine will talk to me in Japanese! (What it is telling me is another matter.) One of these buttons will make the hot water controller in the other room plays a little musical tune! I think perhaps it is a like warning that the hot water will now be used in another room. Because I am living alone and my shower opens off of my kitchen, this feature is somewhat useless. I like to push the button anyway, just because I think it sounds beautiful. ;-)