no heat in 2nd floor steam radiator

John_76

We live in an 80-yr old house with one of those old asbestos-covered steam boilers down in the basement. We get heat in every room except one of the bedrooms on the 2nd floor - the radiator with the newest-looking (copper) pipes going to it from the basement. This is our 2nd winter. Last winter, it worked fine (i.e., the 2nd floor bedroom radiator). This year, we got heat once or twice, then nothing. A plumber came in and lifted the pipe in the basement so it had more pitch and, voila, it heated right up. He braced the basement pipe so it would retain that pitch. But then he left. When the heat kicked off, that radiator never did heat up again. We took the valve off (it's a one-way system) to see what would happen and the pipe leading up to the radiator gurgles and bangs. But still no heat. When the valve is on, nothing - no heat, no noise, nothing. Any ideas?

t. tekushan

cold radiator

I'm guessing that there are actually at least two horizontals in that run of pipe and that raising one puts the other against grade. The run that goes vertically from the basement is probably too long (maybe only by a couple of inches).

Picture this: upper horizontal (somewhere up there) is pitched properly, but basement horizontal is not. Now you lift the basement one and the water runs out of it. The system fires, and the radiator gets hot exactly once, as water may be held in the radiator (depending on pressure). System shuts down and the upper horizontal is now full of water. You're back where you started.

To complicate issues the copper pipe may not be insulated creating excessive condensate counterflow to the steam.

How do I come to this conclusion? I encountered this very same situation where piping had been replaced.

Most likely removing a few inches of the vertical riser will solve the problem.

Also, be sure that the pipe is insulated, and insulate as much as you can get to, even by sliding it up section by section up the riser from the basement.

Hope this helps.

John_77

wow, this makes sense. thank you! but now the question: how do I get rid of a couple inches of the vertical riser? call a plumber? I am only just learning about steam heating and know even less about pipe fitting. is it something a homeowner can do, or should I call in an expert? Thanks again.

t. tekushan

plumber

I wouldn't do it myself. Actually, I would, but if I were you I wouldn't. You'll have to call someone in anyway if it leaks. Also, sweating copper together in close quarters can be dangerous for the novice.

Now, you can remove some vertical length from below or above, but I can't tell you which since I don't know where the lateral lengths are. If the upper lateral is bound by a floor joist or anchor, you'd want to do it from the bottom. If it is near the radiator in question, it can be removed at floor level where the radiator inlet valve is.

If I were to investigate something like this in person, I'd likely loosen the coupling holding the valve to the radiator and see if the pipe and valve easily come up a couple of inches out of the floor when you pull on them. This would tell me that you could shorten it there with success. If not, you have to do it from the basement.

The good plumbers I know understand enough about steam to effectively take care of the problem. But if you are not confident of anyone you might come across in the phone book, you should really call in a heating or plumbing/heating contractor. You really only want to do this once!