Steam Pipe Leak in Ceiling

Fred

The riser will likely never leak. I would say 98% of one pipe steam leaks are on a horizontal pipe where water has pooled over a long period of time. It does happen but rare.

KC_Jones

Yes that isn't a proper coupling. Straight non tapered threads. Plumber should know this, though I am surprised by how many don't.

wildrage

KC_Jones said:

Yes that isn't a proper coupling. Straight non tapered threads. Plumber should know this, though I am surprised by how many don't.

So the picture I took was after the first repair, and it was still leaking from the nipple. He had to go back to the shop and pick up new fittings. He said it would be a good idea to replace the elbow and coupling while everything was opened up. I'll see what sort of coupling he comes back with.

jumper

KC_Jones said:

Yes that isn't a proper coupling. Straight non tapered threads. Plumber should know this, though I am surprised by how many don't.

With modern sealing gook do we still need tapered threads?

MilanD

If pipe is exposed and easily repairable, or on a vertical line, merchant coupling (straight one, like in the picture) is probably fine. On the horizontal, I prefer regular coupling. And on gas lines, never use merchant couplings. Cheap insurance.

KC_Jones

MilanD said:

If pipe is exposed and easily repairable, or on a vertical line, merchant coupling (straight one, like in the picture) is probably fine. On the horizontal, I prefer regular coupling. And on gas lines, never use merchant couplings. Cheap insurance.

The steam pressure relief valve is at 15 psi and a merchant is ok, but gas at almost zero pressure is not.

Not sure I agree with that logic. There is an old thread on this website discussing this very topic.

My opinion on small sizes they are never appropriate, there's a reason they are often referred to as thread protectors.

https://forum.heatinghelp.com/discussion/105950/merchant-coupling-usage

MilanD

That's why I say "probably". I have 100 year old merchant couplings on vertical steam lines. No issues. Myself, I'd never install a merchant coupling on anything, but there It is. Matter a fact, 3 of 4 gas lines on one of my rental buildings failed together at several merchant couplings all at once last year. Pipe dope dried up and there was no taper to the coupling. So, in my book I would not use it on gas. Cost is almost the same, so use regular couplings. Using regular coupling is cheap insurance. Took me 30 hours to get it all repaired. Had to run css lines to bridge all the pipe buried behind ducts and water lines... It was a major pita. Same issue on a 100 year old solid brass water line running in the yard I had repaired last year. It too sprung a leak at a merchant coupling.

jumper

Not a matter of cost of couplings, but making it easier to fit. And easier to undo for somebody in far future.

wildrage

Well the ceiling will be open for a while. I have time to change out the coupling if I want . While I have your attention, here's another issue. The radiator attached to this line has water hammer like a b*tch. The only water hammer in the whole house. I've tired everything over the past 2 years. It's pitched way higher than it needs to be towards the pipe. It's got a new vent. Now that the ceiling is open, I was looking at where the noise is coming from, and it appears to be at the radiator itself..atleast at the valve. What else can I do? Is it possible for the radiator to be pitched too much?

Fred

Are you 100% sure the valve is fully open? If it is partially open or if the disc inside of it has come loose from the stem, water can't drain out of the radiator but some steam may get in. That will cause hammer.

Jamie Hall

If there is a sag in that runout where the coupling is -- which wouldn't surprise me much -- that could be your hammer. Even a smallish sag will allow a surprising large puddle to form, particularly at startup, and the steam will happily pick up that puddle and push it along to the elbow just below the radiator. Where it will hammer like mad. When you get that coupling replaced (have you considered a union?) make sure that that pipe is not only pitched well, but straight. No sags allowed! You may need a couple of extra hangers to get it up there.

MilanD

I was about to write the same thing @Fred said. If pipe is pitched correctly (now that ceiling is open you can check 100%), only other explanation is closed or half closed valve, either by broken off disk or some gunk in there...

wildrage

I'm thinking its the valve. I was thinking that it was the coupling too, but I literally stuck my head in the ceiling while it was hammering, and it was clearly coming from above. Are there ways to rehab these, or do you basically have to replace the whole piece?

Fred

You can take the handle off, take the packing nut off (around the stem) and take the bonnet (larder cap with square nut cast into it_) off. That will expose the internal parts in the valve and you can see if the disc is loose or broken off. On a one pipe system, that valve should always be open so, if the disc is broken, just take it out and reassemble the valve. If it just needs a screw to reattach it to the valve stem, you can do that too.
Make sure the boiler is OFF when you do that so that it doesn't come on and shoot steam at you.

wildrage

Fred said:

You can take the handle off, take the packing nut off (around the stem) and take the bonnet (larder cap with square nut cast into it_) off. That will expose the internal parts in the valve and you can see if the disc is loose or broken off. On a one pipe system, that valve should always be open so, if the disc is broken, just take it out and reassemble the valve. If it just needs a screw to reattach it to the valve stem, you can do that too.
Make sure the boiler is OFF when you do that so that it doesn't come on and shoot steam at you.

Thanks, I'll check it out tomorrow. Oh, and by the way, when the plumber took the old coupling and elbow off, he commented that they were the 'shiny, made in china kind', and replaced it with a US made one. He found it humorous that elbows in this system have lasted 100 years, but this one didn't quite make it to 15.

Fred

Those Chinese fittings are CRAP. If you ever need to do any other repairs/changes, use American made, like Ward.

wildrage

One other question. Should I insulate these pipes? I guess that's a no brainer, right?

Fred

They are under the floor so you really don't need to as that heat is not lost. It is inside the living space and will rise through the floor.

wildrage

I tried sloping this radiator even more and replaced the vent. The vent was full of water. I also noticed that this radiator vents even after the cycle has ended. I thought the pressure may be up to high but i'm set at 1.25 with a 1 diff. This radiator is on 2nd floor, midway in the system. The first radiator to get hot is the master bedroom bathroom (directly above boiler), and that radiator works like a charm.

Oddly, when I tried to disable this radiator when I had a leak, turning the vent upside down did NOT work (it still got super hot), but closing the valve did.

I tried checking out the valve to see if it was stuck closed. Was able to get the packing nut off, but not the next one. I started stripping it so stopped. I suppose I could just replace the entire thing.

Any other ideas? Again:

1. Water hammer from radiator
   
2. Vents rather violently
   
3. Water in vent
   
4. Seems to vent even after furnace kicks off
   

Fred

The venting after the the heating cycle is air being sucked back into the radiator. If the vent was full of water, there is probably water in the radiator, causing the hammer. Turn the Pressuretrol down to .5 PSI with a differential of "1" but more importantly, when is the last time the pigtail (looped pipe that the Pressuretrol is mounted on) taken off and cleaned? They get clogged and allow pressure to build in the system. If the pressure gets high enough, it could prevent condensate from draining out of the radiator. I'd still check that valve also. The second way to check the valve is to turn the boiler off, take the coupling lose from the radiator and look inside the valve. If the disc is stuck closed or broken, try to take it out and reassemble the coupling.

MilanD

Slow down venting. I'm thinking replace that maid o mist with a Hoffman 40, or put on it the smallest orifice that comes in a packet with the maid o mist.

Given that we now know that run us basically of a tee and mostly flat, you may (gently gently) try to lift the whole radiator while still attached to the valve. Perhaps only a 1 or 2 quarter coin thickens and still keep the slight pitch towards the valve. Just a slight help with draining condensate back that loooong rad run out pipe.

wildrage

I've got crazy pitch going on now. All the way to the side of the level.

The pigtail was replaced last year. I have not dissasebled but can verify that when auto feeder stuck earlier this month, furnace shut down. Guage was reporting 5 psi. Low water cutoff is also working.

The plumber had the coupling off to get the pipe in the ceiling fixed, so should be easy enough to do. I'm thinking if I go that far, I might as well have a replacement valve ready. I see they sell them at home Depot.

I did replace the vent with something smaller. Not the smallest, but something on the small side. I think a made o mist #4.

Fred

Don't buy the valves from Home Depot. They are made in China and the internal openings are smaller than a good quality Americam made valve. They seem to be the same as a hot water valve, just labeled for Steam. Not right!

MilanD

Good for the pitch then. Slowing down venting is the only thing left to do plus checking the valve. As Fred said, don't buy Home Depot valves. Supplyhouse.com has ok valves. I used a few and they are fine.

EBEBRATT-Ed

@wildrage,

stay away from the merchant couplings on anything 2" and under they have straight threads. 2 1/2" and up they have tapered threads and are ok to use.

Whatever you do don't close the ceiling until you get the hammering and leaks resolved.

You understand that the HAMMERING is the most likely cause of the LEAK.

that pipe needs to be pitched correctly or you will continue to have problems. You only want to do this once and it's been done at least twice already.

wildrage

@Fred Yea, I noticed that they looked much more flimsy than what's on there now. I'm going too give that second nut on the valve another shot tomorrow. Any pointers on getting it off? Unfortunately, the nut looks pretty well worn from people beating on it over the past 100 years. So far I've only tried an adjustable wrench on it.

@EBEBRATT-Ed Oh yea - no way I'm closing that ceiling until this is resolved. It was so nice when I turned the radiator off because it was leaking - I never even knew when the heat was kicking on - no bangs. I'm sure the constant vibration and banging on the radiator is what caused that coupling to fail.

I made sure the plumber pitched it even a little more. He was able to push the pipe going up to the radiator up another 1/2 inch or so, which in turn increased the pitch to the riser. That being said, I'm pretty certain the problem is the valve or radiator itself. When I stand by it, it seems very obvious, and the other night i poked my head in the ceiling while it was banging - and it was definitely coming from above.

Thanks everyone for your input.

Fred

@wildrage , You need to put a pipe wrench on that nut. An adjustable wrench might break it loose since it has been off recently but a pipe wrench is a better option. When you reconnect it, rock the radiator just a little as you tighten the nut. That will help it seat. Make sure you don't cross thread anyting when you put it back together. You should be able to hand tighten the nut all the way up, if you have it on straight and then use your wrench for the final tightening.

wildrage

Fred said:

@wildrage , You need to put a pipe wrench on that nut. An adjustable wrench might break it loose since it has been off recently but a pipe wrench is a better option. When you reconnect it, rock the radiator just a little as you tighten the nut. That will help it seat. Make sure you don't cross thread anyting when you put it back together. You should be able to hand tighten the nut all the way up, if you have it on straight and then use your wrench for the final tightening.

I was talking about that nut to take the valve apart to check if the disc was still connected or not.

Fred

Oh, they can be tough! If you have a big, good quality adjustable wrench, like an 18", where the jaws will hold snugly, you can get enough torque to turn it off.

wildrage

Heat just kicked on. This is the only damn radiator that makes a peep..so annoying. And only for like... maybe 10 seconds. Maybe 5-10 violent hammers, and done. Just enough to wake me up at 3am

Jamie Hall

wildrage said:

Heat just kicked on. This is the only damn radiator that makes a peep..so annoying. And only for like... maybe 10 seconds. Maybe 5-10 violent hammers, and done. Just enough to wake me up at 3am

Somewhere along the pipe to that radiator there condensate is able to lie in the pipe. May not be the piece you are playing with -- although that seems most likely, but keep looking. What you describe is classic, though -- when the steam first comes on, you get a lot of condensate in the pipe itself as it starts to heat up from cold. That condensate gets pushed along by the steam rushing to get to the radiator and wham. Once the pipe is nice and hot, that puddle doesn't form any more and the banging goes away.

Can be the devil to track down...

Fred

@wildrage , can we get another picture of that radiator from the valve side? Maybe it's the angle of the shot you took but it sure looks like the valve and the radiator don't line up.

KC_Jones

There will almost always be water laying in that coupling, is it enough to bang at the elbow....I have no idea.

wildrage

Here's some more pictures of the offending radiator. Oddly the angle doesn't seem as much as it did yesterday. I have 4 very thick washers under the legs opposite the valve. While water could be pooling up in the pipe near the elbow, i'm 100% sure that it isn't the source of the noise. From next to the radiator, it sounds like someone is hitting it with an aluminum baseball bat. When I have my head in the ceiling during the hammering, hear right next to the pipe, it sounds much more dull, like it's coming from above.

KC_Jones

What size and brand of vent to you have on that radiator?

wildrage

I'll just add that if I remember correctly, the plumber had the valve completely off in order to reposition the pipe coming from the riser in order to fix the coupling. I believe it was both disconnected from the radiator and the pipe from the floor. It banged before, and banged after.

wildrage

KC_Jones said:

What size and brand of vent to you have on that radiator?

I just put a Maid O Mist #6 on it. It is about halfway down in the system. 2nd floor, 30 feet from boiler. Think I should go smaller?

Should be noted that this is a 3 story house. 2 radiators on first floor (formerly had gravity fed steam, now has a second forced air furnace to heat most of first floor, and a little bit of 2nd), 5 radiators on 2nd floor, and 4 radiators on 3rd floor.

KC_Jones

You said you turned the vent upside down and it still heated, did it also still bang?

Just trying to think of all the possibilities here. On occasion venting too quickly can cause issues.

My condolences on someone tearing out parts of your steam and putting in forced hot error.

wildrage

Here's a video of it happening 2 mins ago. I was feeling around, and it 'seems' like the banging is coming from the base of the radiator, about 4 inches from the valve. Valve is vibrating, but base of radiator much more.

https://youtu.be/a39NssGkBxI

wildrage

KC_Jones said:

You said you turned the vent upside down and it still heated, did it also still bang?

Just trying to think of all the possibilities here. On occasion venting too quickly can cause issues.

My condolences on someone tearing out parts of your steam and putting in forced hot error.

Yes, vent vented violently even when completely upside down, and radiator got as hot as ever.

I think it was torn out in the 50's. From what I can tell, all the bathrooms electric, and plumbing got their first upgrade when an owner bought it in 1949...which is good and bad.

Are their gravity fed systems still in service? I was under the impression that they never worked well. I agree about forced hot air. It's good because there are very few moving parts, but as soon as it turns off, it gets chilly again. There's nothing quite like a blazing hot cast iron radiator .