Steam heat - radiator runs in the summer?

My home is heated by radiators that use steam heat, somewhat old-fashioned and becoming more obsolete from what I'm told. Anyway, at times during the summer random radiators will occasionally start heating up, and I can't figure out why. My boiler is used to heat our hot water, but it's not like this only happens when hot water is being used, which I would understand.

On top of it all, over the last year water stains have slowly started appearing on the ceiling directly under the radiator in my daughter's room, which I believe is the last radiator in the "circuit" and also the one that seems to randomly heat up the most often.

Any ideas as to what the problem is? I know little to nothing about how this system works, so I have no ideas about how to fix it. Any input would be greatly appreciated. Thanks!

 

First I would say you have a control problem. The boiler seems to be overheating & producing steam when it should not go over about 180º just for the domestic hot water. It's hard to tell where the water is coming from. Just look over the radiator very well. There should be some tell tale signs.

 

Unfortunately the summer has gotten away from me & I haven't addressed this yet. Yesterday when I got home, my wife told me the dripping noise in the living room ceiling seemed to be coming faster. The ceiling does actually look like it's caving. When it happened yesterday, my wife had been running hot water for a while, and the radiator above the spot on the ceiling was slightly hot. I pulled off the radiator cover & the carpeting around the pipe, but I don't really see any telltale signs of what's happening. Short of either ripping up the floor boards or the ceiling underneath, I don't know how I can see what's going on.

I think I've decided this problem is over my head, and we're looking to find a plumber to come take a look. But as a last ditch effort, I thought I'd revive my question and see what thoughts anyone has. Grady mentioned there might be a control problem & the water is overheating - how do I fix that, just change the temp control on the water heater?

Any advice would be much appreciated. Thanks as always---