Wow, what a winter. We just get power back after five days in the dark, have a few days of relative peace before the holidays, and now 18 inches of new snow. I love living in Maine.
My question is this- I replaced a steam pipe going to a radiator on the second floor earlier this fall due to a remodel of the room on the first floor. The old pipe was 1 1/4 inch iron pipe and I replaced it with 1 inch copper and sweat fittings. Now, I can’t get steam to that radiator now matter how far I open the air vent. I have replaced an iron pipe on a different radiator with 1 inch copper on a much longer run and I have no problem with that one, what did I do wrong this time?
I can feel the new pipe is hot past the old junction, but the heat dies about a foot away from the original main pipe.
Replies
Did you insulate the pipe? Sounds like a very large pipe. Are you talking inside diameters? 1 1/4" serving one radiator in a residence sounds way big ... but I ain't a steam expert.
! inch is the outside diameter of the pipe. One inch is one of the smaller pipes. The two pipes leaving the boiler are 3 inch. Most of the system is insulated.
Go to this site http://www.heatinghelp.com/
Post your questions and you will get help and can also find books about steam heat that will explain how the various systems work. The venting is very important. If the vents don't let the air in the system out steam can't get in. Most systems were designed to work at less than an one psi. Low pressure steam moves faster (intuitvely it seems that cranking up the pressure is the answer but it usually is not).
Mr. Jackson seemed to have some good notes.
If you are missing insulation at a key point, that could be your weak point where condensation collects and plugs the pipe.
I'm assuming Mr. Jackson's take is right ... you have a single pipe type steam system with air vents on the radiator. If you alter the physical configuration in the least, you could end up w/ a place for condensate to collect. The pipe has to drain back to the boiler. I'm assuming you knew that ... but assumptions will always bite us.
Yup, everything pitches back to the boiler. I checked last night and the pipe is getting warm farther along than it had been. We had a cold night and the boiler was running more than it had, so maybe it just might take a while to get hot. Not a huge problem, as the room is directly above the woodstove, so not too chilly. Thanks to all for the tips and hints, and I am always thankful for this resource and people who are willing to help out. Have a safe holiday season.
Dan
Is the pipe rising all the way to the steam rad? You might have a "water plug" blocking the pipe where the steam has condensed.
I'll second that. I have one-pipe steam radiators and the system is about as simple as you could ask for. As long as the steam has a clear path to rise up through the piping to the radiator it works. If the air escape valve on the radiator fails in the closed position, the air in the radiator and it's supply pipe has no way of getting out of the steam's way, so the steam will not rise up the supply pipe. If the supply pipe has any spot where water can collect that will almost immediately result in a blocked steam flow too. By design, condensed steam from the radiator flows back down through the supply piping and returns to the boiler, to begin the cycle of life all over again ;)If you don't think you have a low spot in the pipe that's 'plugged' with water (like a drain trap), try just removing the radiator's air vent completely as a test. If steam doesn't find it's way out that hole by the time other radiators near it on the main line are getting warm, look for a blockage in it's supply piping somewhere.If your new copper supply pipe is drastically longer than the old iron pipe it replaced (because the radiator was relocated), remember that copper is a better conductor of heat than iron and the pipe will give away more of the steam's energy to the surroundings. If the run goes far enough and it's not insulated, consider that all the steam could get 'used up' and condense before it ever reaches the radiator.But I'm still guessing either a water blockage or air vent problem. Good luck! :)-John
Edited 12/22/2008 3:29 pm ET by JohnPJackson
Unless you've down-sized the radiator drastically, never reduce the pipe size in a steam system, especially in a riser. The steam will have a much harder time making it through the returning condensate, losing it's energy to the water. There's guidelines for the sizing on the Burnham site here: http://www.burnham.com/PDF/htghelper.pdf