Steam Pipe Leak in Ceiling

Fred

If the only problem is with that second floor radiator, that shares a riser with the third floor, just slow that third floor venting down and see if that keeps the banging at bay. Once that is done, you can replace/adjust the vents on the other radiators as time/money permits so that when you are done, all radiators are heating within three to five minutes of each other.

acwagner

@wildrage your calculation is right, but schedule 40 pipe is defined by internal diameter. Check it out:

https://www.engineeringtoolbox.com/ansi-steel-pipes-d_305.html

Based on your exterior pipe measurements, that radiator is fed by a 1" pipe, which is too small for that radiator. Your riser is probably 1 1/4" or 1 1/2".

You'll need to get a smaller radiator for that room. 1" pipe is too small for steam and the returning water. That's what's causing the hammer. It may also explain why the radiator heats up so slowly. A smaller radiator will make the hammer go away. Get a radiator at that is 20 EDR (4,800 BTU for steam) or smaller.

Whether a smaller radiator will heat the room enough is another question.

Fred

Also, make sure you always keep the system pressure as low as possible, Pressuretrol set at .5 PSI Cut-in and Differential set at "1" and the Pigtail (looped pipe the Pressuretrol is mounted on is cleaned at least every season so that, if the boiler is over sized and the boiler wants to run a longer cycle, the Pressuretrol will keep it at a low pressure. I think we've already talked about making sure you have plenty of Main vents on each main. That's critical to minimizing pressure build up and even steam distribution.

KC_Jones

You can't make a blanket statement that 1" is too small for steam. It may be too small by classic sizing standards, but to determine if it's too small you need to look at how the entire system was sized originally.

My personal system has 1" pipe for the entire second floor. My bedroom has a radiator of 40 EDR on a 1" pipe and it's quiet and heats fully without issue.

I'm not saying it isn't his problem, just cautioning to be careful making blanket statements like that. I believe @gerry gill has spoken of this before with respect to sizing the pipes.

acwagner

Good point and you're right, @KC_Jones

wildrage

@acwagner

You know what? I never thought about it. Every other radiator that is teed looks like this:



And the problem radiator looks like this:



I do have much larger radiators in the house, but they are not teed.

Hmm...where to find a nice selection of old radiators? I think there's a place in philly.....

Fred

I think he'll be fine if he slows the venting on that 3rd floor radiator that shares the riser with the noisy one. Let's keep in mind that house is 100+ years old and I'm sure they didn't live with hammering all those years. The Homeowner said when he bought the house he replaced all the radiator vents with huge ones because he thought that was the right thing to do. He just has to get things tuned back in, starting with the noisy one.

wildrage

Fred said:

I think he'll be fine if he slows the venting on that 3rd floor radiator that shares the riser with the noisy one. Let's keep in mind that house is 100+ years old and I'm sure they didn't live with hammering all those years. The Homeowner said when he bought the house he replaced all the radiator vents with huge ones because he thought that was the right thing to do. He just has to get things tuned back in, starting with the noisy one.

@Fred I don't know. This radiator doesn't match the other ones. Does it look newer to you? The bathrooms were renovated in the 50's. Do you think maybe they thought that particular one was drafty, and just stuck a bigger radiator in it? If you look at my reply above, all the other smaller radiators seem to match. The bathroom in question isn't much bigger than the others.

Fred

You never know but I can tell you I have the same combination or radiators in my house and I'm 99% certain they are all original. Most of the main rooms have the rocco column radiators and the bathrooms and a hall near the back of the house have those tube type like you have in your bathroom. I almost think they wanted to spend a little more for fancier rads in areas of the house that were more social/living areas and used a plainer radiator in utilitarian spaces/bathrooms.

wildrage

Fred said:

You never know but I can tell you I have the same combination or radiators in my house and I'm 99% certain they are all original. Most of the main rooms have the rocco column radiators and the bathrooms and a hall near the back of the house have those tube type like you have in your bathroom. I almost think they wanted to spend a little more for fancier rads in areas of the house that were more social/living areas and used a plainer radiator in utilitarian spaces/bathrooms.

I'll see if I can get it working as is, with proper venting. In the mean-time, I found a salvage place in philly that has thousands of radiators in stock...and there never seems to be a shortage of people ditching their steam systems and selling their radiators on CraigsList...so I'm not terribly worried about finding a new one if I have to.

Fred

Just remember, if you change out the radiator, you have to replace both the spud, in the new radiator AND the valve on your supply pipe. It is certainly do-able but it takes a lot more work that just switching radiators. The valve and spud need to match.

acwagner

Adjusting the venting will definitely be easier on the back. I think I can make that blanket statement

wildrage

@Fred , @acwagner LoL...I know. Especially in this house - it's massive. It's a PITA just to go down to the kitchen and get a glass of water. Bringing one up would definitely not be fun.

Yea, I have an idea of the process. Spud wrench to take out spud. May need to cut out with a hacksaw, which looks real fun.
Remove valve from supply pipe (it was removed to fix the pipe, so atleast it isn't steam welded on), reverse process to install, right?

EBEBRATT-Ed

Here's something else to consider.

I am sure no one will agree with me. But he drained 2-3 cups full of water out of that radiator according to his post. I don't like the bushing in the radiator.

Pull that bushing out and use an eccentric coupling (or bushing if you can find one). That 2-3 cups of water sitting their could be the problem and it's an easy fix.

You might have to put the rad up on some blocks to make it fit.

By the look in the picture if the stub going in the rad is 1" the bushing is probably a 2 x 1

wildrage

@EBEBRATT-Ed That's a good point. I thought at a minimum i'd try to clean it up as much as possible with a wire brush.

By the way, these are the vents I pulled off the radiators when I moved in 2 years ago. "Hoffman Siphon Air Valve #1" 1936. Still seems to work pretty well!

MilanD

I missed quite a lively discussion on here...

I am going to agree with Ed, I mean that bushing and gunk in the back of the rad is pooling water just in front of the the spud and behind the bushing. As soon as steam hits it, it collapses and - BANG!! Why this one is doing it and not other rads that are also bushed? I have no idea...

We all know hammer happens with either collapsing steam or steam picking up water and slamming it on the el. Unless water is pooling in the coupling under the floor, this is the only other place it can be pooling, and it looks like it is...

You may try to do as Ed suggests with an eccentric bushing or pipe/reducer, or try fill the void with some kind of material to raise the waterline in the radiator.

wildrage

@MilanD There's still no banging....have gone through 8 or 9 cycles since i changed out the vent yesterday. I get a clicking, which I believe is just expansion noise, but that's it. The radiator always gets partly hot, gets fully hot every 2 or 3 cycles depending on the call for heat.

I have no yet installed the smaller vent upstairs. I'm leaving for Florida tonight and hate making any changes to anything when the house will be empty for a few days. Will try the smaller vent on the 3rd floor later this week when I get back - hopefully that will cause the radiator in question (below it) to heat up faster.

MilanD

@wildrage - Looks like you may have gotten the balance right. Great!

Fred

There is a trough in virtually all steam radiators that holds some water. They are designed that way to collect any rust or gunk that builds up. It doesn't hurt to clean them when you have the opportunity but I doubt that is any issue at all. Venting is the issue, especially since this radiator shares the riser with the third floor. Slow the third floor vent down and the second floor will resolve itself.

wildrage

Thanks guys! I'm still going to leave the ceiling open just in case haha

EBEBRATT-Ed

It's probably a combination of things. Many time trying to fix a problem you (we all) look for one answer when actually theirs two problems.

I suspect some water pooling due to the bushing and that this becomes a non issue if the venting can be slowed down enough to make the condensate a non issue.

Time will tell. If you get enough heat with the venting slowed down...fine

RomanGK_26986764589

I really like that Hoffman No 1 vent! Looks like they're not sold anymore. I bet it's few decades old.