Banging is caused by wet steam, which is caused by dirty water in the boiler. When was the last time you cleaned the water?

Banging in a steam heating system is almost always caused by water hammers -- poorly sloped pipes allowing water to collect.

The steam moving towards the radiator pushes the water ahead of it and slams it into an elbow or far side of the radiator...

BANG.

Wet steam normally causes a rise in fuel bills and can, under severe circumstances, cause or greatly contribute to banging, but generally not.

Tom,

You don't say when your home was built, but I sincerely doubt that the joints are leaded. You'd be able to see if they were. The house I grew up in had steam heat added in the 1890s, and none of those pipes were leaded.

Chances are that the elbow is a maleable iron fitting, meaning that you could be able to break it away with a heavy hammer.

As for why you decided to take the radiator out...

What did you do to dianose the problem before you resorted to the tear out?

Given the nature of steam it's often quite difficult, if not impossible, to put a radiator too far away from the boiler for it to heat up.

You can normally solve the problem in any of a number of ways, but it sounds as if you're beyond that now.

And no, a rubber couping would not be sufficient.

Agreed. If the radiator had settled so that it or the supply pipe was water bound, that that was the reason that it banged and did not heat.

If you can't get a hammer near the fitting, an experienced torch man can also burn out a nipple with a torch, but it is potentially very dangerous.

Use a longer pipe on your wrench.

It sounds like you are screwed at this point.

Guys, Thank you for the replies so far. I appreciate the input.

I decided to take out a third floor radiator because it was on the far end of a two main system that had been added onto many times before, all of the add ons being "upstream" from a riser that goes straight up three floors. The main for this riser snakes around the entire basement feeding most of the house before going up at the very end and the radiator in question was at the very top.

After working out the kinks and banging in the remainder of the house, large 1890 victorian, the remaining issue was this radiator. Incidentally, changing the main vents and getting rid of a horribly done added on radiator in an addition that was fed through an unheated crawlspace solved most of the issues.

Had someone look at it, radiator, and went through the possibilities myself, changed the vent, sloped the radiator, took it off and drained it, made sure the valves were open and still no heat hence the conclusion that it was a location problem. My thought was that with all of the add on's and the fact that pipes were from a coal system, I was fighting an uphill battle. The two radiators immediately before this last one on the riser were also not performing well and are more important as they are in the master bedroom and dining room.

And yes, it was just a forlorn hope about the rubber coupling as my thought was that I would be creating a nice rocket launcher if i did that. I was hoping that there was a double secret coupling I did not know about.

I had previously had to remove or move pipes in the house previously and had no problem with the fittings, enough leverage and they came out --

I agree that I appear to be screwed -- with the added problem being that I do not have much room to get at the fitting.

Comments, criticism and suggestions are again greatly appreciated.
Tom

Can you cut it back some more and attach the cap to the next joint closer to the boiler, using a short nipple, too, if you need to?

Do you have enough room to get to it with a reciprocating saw?

Chance are even if you get the fitting loose you're going to have to chase the threads with a die to clean them up enough to get a cap screwed on, so you might as well just saw it off and chase all new threads on the stub.

Or, better yet, stub it off at the main in the basement.

OK, that said...

Glad to hear that you replaced the main vents. Most people don't even know they exist.

A secondary venting solution would have been to put two air vents on the poorly performing radiators while throttling back on the vents on the radiators closest to the thermostat. This would slightly less than double the speed at which steam would hit them and would give them a better chance to get a head of steam up.

But, that said, you're right, it could simply be the fact that the boiler was literally out of steam.

I grew up in a similar type house, HUGE Victorian with the old coal boiler converted to oil in the basement.

Finally, the last possible problem, one I've heard of before...

At some point in the past the mains could have flooded due to a bad feed water valve, and that could have flushed large amounts of crap down to the ends of the mains, effectively blocking them.

Brewbeer -- my problem is that while i can cut back and go to the next joint in line, whats to say that this one will come out. Also, the joint i was planning on, the one I can't get unstuck is a tee, with the master bedroom radiator on the tee. I will have to redo the tee if I cut back to the previous one and that runs through the floor currently -- ugh. There is an exposed coupling below that I can get at, it is just a coupling, two female ends connecting a run of pipe -- when you say break it off do you literally just whack it with a hammer or sledge until it breaks? I know that sounds kind of ignorant, but I have never been unable to get the pipe/joint turning before.

kframe --
You are inadvertantly commending yourself and the other fine folks here on the gardenweb as I have trouble shooted and fixed my steam system (and lots of other things in my old house) with your guys help over the past three years. The main vents were a particularly helpful tip.

I don't think its the mains getting clogged as the two radiators below the one to be removed on the riser work great until the one I'm removing gets consistently involved.

My half baked theory is that that the length of the main plus the riser then going into a room that is consistently cold causes the steam to condensate by the time it hits the third floor leading to the whole riser backing up and shutting down.

I tried to throttle down on the lower and closer radiators and opening the third floor all the way and all that happened was the whole house was cold. I have gone so far as to run the system with everything down low and the radiator that I am dealing with with the valve off and the the radiator still does not get warm, boiler shuts off before it gets hot.

If i cut into the floor, i likely can get a reciprocating saw in there -- what can I do with it other than ritual hari kari before my 8 months pregnant wife finds out she cannot turn on the heat.

"what can I do with it other than ritual hari kari before my 8 months pregnant wife finds out she cannot turn on the heat."

Wait awhile. She'll do it for you!

OK, I think I'm seeing the problem.

I THINK what I'm visualizing is, quite literally, a mess.

T-ing a steam radiator usually isn't the best idea. It's usually attempted on systems where part of the house was originally plumbed for steam heat, and then more was added on.

Unless I miss my guess, this simple diagram gives an idea as to what you're looking at.

{{gwi:1597298}}

If so, definitely not optimal. In the optimal situation each radiator would be supplied by its own supply riser.

I really doubt that it's a case of the steam hitting that 2nd to 3rd floor rise and losing all of its will to live; I think it's more a combination of the dynamics of your system and how it was put together.

I think your best bet right now is to call in a plumber and have him cap the line off.

Yes thats the idea, though add another floor and another radiator at the top of the diagram and most of the home's radiator's off the main that leads to the riser.

I also looked at the main that feed this riser. It ends just after the riser and the main vent is right there. Even with it, the main vent, doing its job and letting the air out of the main, there's got to be still a ton of air in the riser right-- can a radiator vent handle that?

Thanks again.

Hobbs,

I knew I missed something...

That tall straight line isn't supposed to be the main...

That's supposed to be the riser coming OFF the main.

Most steam mains in older heating systems will be between 3 and 6 inches in diameter.

Most risers are 1 and 1/2 or there abouts.

I didn't show a main in my diagram, but you can, and should, have multiple risers coming off one main, by the way I think about it is that you should only have one radiator connected to a single riser.

What you're describing, at least to me, is multiple radiators served by the SAME riser.

As for the main vents, well, they're designed to vent the mains, NOT the risers. Main vents technically CAN'T vent the risers.

Risers are vented by the air vents on the radiator.

Just an update and another note of thanks.

After i fitted my recip saw with a metal blade and was getting set to cut out the pipe in the fitting, I decided to give it one more try with a bigger pipe and wrench. After a few moments there was a giant screetch and the pipe started turning. I was able to cap it off as planned without much trouble and the house has been amazingly quiet since we turned on the heat. Whether or not it was based upon my theory or who knows???? Thanks all.

For those with steam heat -- cleaning the boiler water, replacing main vents and changing the radiator vents really does work fantastically. We have gone from constant loud banging in every room, sounded like we lived inside a bell, to almost complete silence. My wife told me I'm awesome at least three times as a result -- always a good thing.

"My wife told me I'm awesome at least three times as a result -- always a good thing."

But... you haven't thrice told us that we're awsome! :-D

Glad to hear that you've gotten everything squared away.