I should also mention the boiler is 30 years old or so, but as I said, it very seldom gives me trouble.

There are four old-looking wheels, four switches, and three pipes, from what I could see. NONE of the wheels has any indicators. The front pipe has two wheels. The next one - a skinny one in the back that connects to a horizontal one that runs maybe the whole length of the room - has one wheel and two small, rectangular metal switches that look like tiny levers. The third pipe, in the back, is thick and connects to another horizontal pipe, well over my head. That horizontal pipe has one wheel and two switches - one is an old one that is oval and looks like the head of a key. The other is rectangular and is on the newish hydronic expansion tank.

I also tried comparing the positions of those four switches to the ones on the other 15 or so boilers in the room. Trouble is, many of them seem to be in multiple positions. (I doubt anyone else here would have chosen to keep the heat off until now.) Some are in the same positions mine are.

I suppose I could send a photo to one of the contractors who came here and ask if one of the switches should be turned. Obviously, if they forgot to turn a valve back on during the fall inspection, I wouldn't want to pay them to come back and do three seconds of work.