2-pipe conundrum in SF

ElisabethInSF · February 2016

Update on 2/12/16. I shut off the valve at the kitchen radiator last night to see what would happen during the net heat run. This morning when the heat started up some different things happened. The main thing is that both pipes at the kitchen rad got hot, indicating the the section of pie that goes into the wall is indeed the supply for the rest of the apartment. The kitchen rad of course stayed cold, though the section of pipe leading to it eventually got somewhat warm. There were some odd scraping and hissing sounds at times as well, and the occasional banging that did not sound like the usual water hammer I experience.. But the main thing that was very different was that the dining room rad that normally doesn't heat at all or does so after the system has been sending steam for 1.5-2 hours, heated the most quickly and without all the racket it normally produces. But the living room and bedroom rads didn't heat at all, though the returns were warm. Eventually they started to feel hot on the supplies only, but then the system shut off, so I have no idea if they would have eventually heated all the way through. It's just not cold enough in SF right now for the heat to run for very long, unless I ask my neighbor to turn the temperature setting low so it keeps going. May ask him to do that this evening and leave that valve shut of just to see how it goes.

Here are a couple of videos I did.

Any thoughts?

Fred · February 2016

Is that another valve under the kitchen pipe that has its knob missing? If so, is that valve open? That's the one that feeds that rad.

ElisabethInSF · February 2016

Hi Fred,

It sure is. I just removed the handle off the top one and put it on there, and was able to turn to closed position.

The odd thing is that that valve was open this morning; I only closed off the top valve. Yet that rad did not heat except on the short length of supply pipe.

Are you sure the lower one is for the rad, not the whole supply going to the rest of the flat? The reason I ask is because with the top one shut this morning, steam was still passing through to the wall and at least making it to the dining room rad.

Do you think I should shut the bottom and leave the top open and see what happens? The heat will come in about an hour here, so I can see what happens.

I'm assuming that shutting valves willy nilly won't make anything explode! Or cause permanent damage!

Fred · February 2016

That bottom valve is definitely just for that radiator. If you shut the top one off and it still let steam through, either the valve isn't working (the internal disc is gone or broken) or that pipe doesn't feed the rest of your apartment. Closing those valves won't do any damage but rest assurred the bottom one is only attached to the pipe that feeds that radiator and the top valve is for both the pipe in the wall and that radiator.

ElisabethInSF · February 2016

Come to think of it, those valves might both need replacement. I mean if the top one is supposed to cut off supply, it certainly didn't do that this morning when I had it all the way closed. And the one underneath was open, but the rad didn't heat except on the pipe leading to it. Perhaps some some steam was getting past the valve but not enough to heat all the rads. The only one that got fully hot was the dining room one. The system shut off about 1.5 hours after it fired up.

JUGHNE · February 2016

If the wall pipe feeds some other rad on your floor, then the steam must go down and under the floor and back up to the next rad. That piping constitutes a water loop pipe trap under the floor and will eventually completely fill with water. There would usually be means to remove this water with a "drip" connection. I wonder if there could be another short circuit from that underfloor steam main to the return that exits out the back wall. The plot thickens.....if that pipe stays full of water the steam will try to push it out and give you severe water hammer.

If you have the top/newer valve off with the steam up you could hear steam travel if you opened the valve slightly. True it may not be sealing off 100%..

Or when the boiler was moved they might have tied the underfloor supplies together for your floor. Maybe the steam is backfeeding from your neighbor.

A simple stethoscope could be a wood dowel or such and you can hear the steam travel. More CSI work.

SteamCoffee · February 2016

Remember you have a steam main not isolated from the returns, you may be logically shutting off the steam supply, but steam will enter the system from the return... Shut the bottom and leave the top open, report back...remember, we don't know anything about your systems configuration under the floors....

Fred · February 2016

I'm thinking that pipe that goes in the wall, if it feeds other rads in her apartment, may go up and across the ceiling and then drop down, which would allow it to feed some upstairs rads as well. What she hears, under her floor may be returns and they may have steam in them from a failed (or missing) trap. Just a thought. A real PRO/sleuth needs to be on site for a day to map this system.

ElisabethInSF · February 2016

Ah, to find a real pro sleuth!!!

I shut off the bottom valve this morning but left the top one open. The top pipe coming in and going to the wall was hot with steam, as was the small section of pipe that feeds that rad (same as when I shut the top but left the bottom open yesterday), but the rad was cold. At this point all the returns/steam trap housing were piping hot on the more distant rads, though supplies were cold. Then I opened up that lower valve at the kitchen rad. A short while after that the returns became cooler and the supply pipes got warm and started filling the radiators. I suppose that might have happened anyway, and that opening that lower kitchen valve around the same time was incidental.

This is so odd. Overall the noise was less than usual. Except the under floor piping started hammering about midway through the cycle, probably about the time condensate started making its way back to the boiler. But the start up was pretty quiet, though it did take an hour and a half before my rads got sufficiently hot.

I went to the boiler room while the system was running for about an hour and the pressure was 3 psi. The sight glass showed water level only about an inch above the bottom of the glass. Evidence of discharged water was outside there on the ground, so it obviously was a bit overfilled when it started up.

I visited my upstairs neighbor on the other side of the building last night and took a picture of his kitchen rad. See it attached here. He looks to have the same thing going on - one pipe coming from outside (on right of pic), one entering the wall (left) and one to the rad. The only difference I can see is that his return is just like on the other rads,where mine has an extension and a much large pipe heading into the floor.

JUGHNE · February 2016

This is my latest best WAG. FRED rung the bell with the word "up".
The pipe into the wall goes up into the ceiling to your other rads. All of your other rads are fed from the wall at the upper inlet of the rads. So there could be a pipe going up between the top floor joists but where perpendicular to the joists the piping would be either notched up into the top floor joists (structural issue); drilled thru floor joists....PITA with rigid pipe; or drop the ceiling.....or provide soffits/ or crown molding that could hide a pipe below the ceiling.
The supply could be tied together from side to side apartments. The wall mystery pipe looks to be only 1" and could not provide much EDR. Feed from either side could help the piping size....improve pressure thru a backfeed loop. These returns may go out the back wall thru the check valve. The crazy loop tie would put steam into the returns. This would be why the floor gets overheated, the returns become a steam pipe.

The top floor may have the same supply piping but have returns that exit out from the top floor thur the deep (6-7') water seal on the outside of the building. This looks to come out under the top floorboards.

(can you see upstairs at the kitchen entry point where the lower return pipe exits....or is it under the floor??. the opposite top kitchen rad may drain into the floor into this lower return pipe.)

The top floor opposite you, (last pictures) show a pipe in the corner...do you know what that is??

The kitchen above you could have had the valve simply shut off and the rad removed. That piping should be obvious under the new counter. If they capped the pipes from the outside and the mystery wall pipe, then maybe all the steam comes from the other inlet IF the steams are tied together as mentioned above. It is hard to imagine cabinet installers/carpenters/general contractors going thru the effort to reconnect the inlet to the wall pipe.

From what I have seen with these projects is that they would just remove the rad or at best just cap each pipe off. ("we don't need these old pipes anymore....they don't do anything anymore....look, there is no water pressure in them")

aircooled81 · February 2016

Is anyone going to eliminate those cross connections between the returns and supplys?
There is a lot going on, but those pipes outside, that tee the return and supply really need resolution.
I can only picture steam migrating up the return pushing condensate out of its way. Those are a huge problem!
Wish i was standing next to the guy 50 years ago that piped those in. After he finished what he was smoking, im sure wed have a good laugh over that crazy idea!?
That also explains to me why the scabbed in that overflow at the boiler. Kinda hard to return condnesate right away when your supply is filling your return pipes. Im sure eventually enough condensate builds up to overcome the steam, but by then the make up water has already filled the boiler, so it just dumps the excess condensate.

ElisabethInSF · February 2016

Interesting thoughts JUGHNE! I never thought about the possibility of the supply going up into my ceiling then down to rads. If that is the case then the return lines are what make the noise because we hear nothing from the ceiling area, only under the floors and at the rads of course. The neighbors above me enjoy silent heat (they're the only ones in the building who have no complaints), so they are not hearing anything from any pipes that are in my ceiling/ their floors. The pipe that you see entering above my kitchen window/neighbor's floor level is going in at what appears to be just above my kitchen ceiling and under their floors. Is it possible that my supply runs in my ceiling and for them it's under the floors (of their apt)?

This really is a conundrum as I said in my first entry!

I don't know what that pipe in the corner of my opposite neighbor's place is, but it isn't visibly related to the radiator that we can see. However if you look in the attached pic you can see there is a low pipe that was capped off at some point coming out low on his kitchen wall. I have a similar one in my apt next to the kitchen rad return, as seen in the second picture. Is this evidence perhaps of how they made the adjustment when they moved the boiler? Does it provide any clue about what they were doing? Besides smoking dope that is!

We do have fairly large crown molding, so I suppose there could be pipes hidden there. Then again, this place was built in 1922 when many places installed crown molding for stylistic purposes.

ElisabethInSF · February 2016

aircooled81, that crossover loop is high on the list of things to evaluate with a professional! Everyone here has mentioned how wrong that seems. Your observation that it could contribute to the water discharge that happens at the beginning of every heat cycle makes a lot of sense. Somehow the boiler is over filling in between cycles that much we know, as the water line in the sight glass is so far up to the top as not to be visible in between boiler cycles. Then when the boiler starts, it dumps how ever much it needs to to make head room for steam to exit.

I know of two outfits that have serviced the heating system in this building in the past 20- years. Both have decent reputations locally. Hard to imagine how they overlooked the loop and thought "hey, lets just put in a pipe on the return in the boiler room that can dump the excess water." I keep thinking that maybe something will make sense about all this, like someone will point to something they observe that explains why it is constructed this way. But the more we look at it, the more it seems like the guys who did the adjustments had their clown shoes on when they did the work.

JUGHNE · February 2016

Does Greg's kitchen rad cond drain go into the floor?
The corner pipe comes out of the floor....has a rag laying on it...what is the fitting on the bottom at the floor. He also has a pipe stubbed in thru the wall from the outside?? looks like a copper cap on it??.

Your kit rad floor has a pipe/valve/cap stubbed up....could that have been an old gas pipe for a range?

What might show where steam pipes are is someone with the high dollar IR Flair camera. It can see pretty well thru walls. Firemen use this to find hot spots inside walls.....that way they don't have to axe the whole place open. There are pros who use this to see how a rad might be heating or to locate leaking hot water under floor piping. On day with the steam up it should locate hot pipes, (+200 degrees) thru the floor, walls, or ceiling.
(It is cheaper than using an axe)

I do agree with others that the outside return loop should be disconnected.....first major issue that will change things.
The check valves can be disabled by unscrewing the top of the wye fitting (can be a real bear, but is possible...I have done it) and removing the swing flapper and put the cap back on and then it is just an another section of pipe. (Is reversible but I doubt if needed).

People must smoke a lot of things out there.....

...and wear funny shoes also.

ElisabethInSF · February 2016

Yes, Greg's kitchen rad return goes down into the floor and looks just like the returns on all my rads except the kitchen one.

I suppose that pipe in my wall could be from an old gas stove, though the original stove was in here when I moved in (beautiful 1920's Wedgewood), but I was told that it was not "to code" so they took it away and installed a new one in the same spot. I don't recall that they capped off any gas lines or added a different one to connect to the new stove.

That IR camera idea sounds stellar, and would help solve a big part of what we are dancing around here - seeing what the heck is happening behind the walls. I need to find someone who has one!!

SWEI · February 2016

ElisabethInSF said:
the original stove was in here when I moved in (beautiful 1920's Wedgewood), but I was told that it was not "to code" so they took it away and installed a new one in the same spot.

In SF? More likely they sold it to the antique stove guy who restored it real pretty and sold to for $8k to some decorator job in Pacific Heights.

ElisabethInSF · February 2016

Lol, I had the exact same thought when it happened!

ElisabethInSF · February 2016

Update for those that are still looking at this thread...I had a heating professional out here this morning to do a consultation. He took a very thorough look at the entire system (no boiler blinders on him!), and he's going to put together a task list and estimate to get it all working as the Dead Men intended. There was certainly a lot of head-shaking and frowning as he walked around, let me tell you! I handed him the list I had compiled from all of your wonderful input and he agreed with it thoroughly. He also had a few thoughts on what they did wrong when they moved the boiler.

Interestingly, he wondered how I came to know so much about all this and when I told him he said "I know Dan! I've taken some of his classes/seminars." Small world :-)

And now for the next step - convincing the landlords that the work will be worth the investment...

Thanks again everyone, for your generosity, patience and stellar advice!

Fred · February 2016

That's great news! Hopefully your Landlord will listen.

ElisabethInSF · April 2016

Hi Everyone,

Thought I would close the loop (or should I say vent the return!!!) on this discussion from way back. After much back and forth via email, I was pretty much told by the outfit that assessed our system that it's too far gone, such a hack job, and so filled with problems that it would be better to convert to another type of heating system. The suggestion was to run separate gas lines to all the units, install condensing boilers (or combi-boilers) in each unit, abandon the old steam runs inside and outside the building, and install PEX tubing leaders to the radiators. They suggested that this would offer huge efficiency gains, with the added benefit of independent metering for each apartment, and it would be (virtually) silent. So I suppose that scenario would address the main complaints we have. But the cost is pretty high! And obviously there would be the removing of existing piping, asbestos, some interior and exterior carpentry and painting... I see a huge bill with all this. But it does seem like a valid proposal. Curious if anyone hear has any thoughts about this suggestion, or experience with this type of set-up. Any feedback is appreciated!

nicholas bonham-carter · April 2016

A hot water conversion can have problems, as the operating pressure is much higher than it was with steam. Since they would run new pex, maybe it would be a possibility.
The heat loss for each apartment would be so much smaller than the smallest boilers, that they would short cycle. One boiler could handle the whole building.--NBC

RJ_4 · April 2016

call ABCO mechanical contractors in SF I worked for them for 20 yrs before I retired there steam pros ask for Nick

jumper · April 2016

This long thread shows that steam can work no matter what.

Steamhead · April 2016

ElisabethInSF said:
Hi Everyone,

Thought I would close the loop (or should I say vent the return!!!) on this discussion from way back. After much back and forth via email, I was pretty much told by the outfit that assessed our system that it's too far gone, such a hack job, and so filled with problems that it would be better to convert to another type of heating system. The suggestion was to run separate gas lines to all the units, install condensing boilers (or combi-boilers) in each unit, abandon the old steam runs inside and outside the building, and install PEX tubing leaders to the radiators. They suggested that this would offer huge efficiency gains, with the added benefit of independent metering for each apartment, and it would be (virtually) silent. So I suppose that scenario would address the main complaints we have. But the cost is pretty high! And obviously there would be the removing of existing piping, asbestos, some interior and exterior carpentry and painting... I see a huge bill with all this. But it does seem like a valid proposal. Curious if anyone hear has any thoughts about this suggestion, or experience with this type of set-up. Any feedback is appreciated!

In other words, they think they will make more money that way. Find someone else.

ElisabethInSF · November 2018

Greetings Heating Help!!! Wow it's been years since I've considered my heating problems or visited this site. I learned so much from all of you, and spent a lot of time reading up on 2-pipe systems, and figuring out what the heck they did wrong over the years with our system, but alas I could not repair it myself. My neighbor and I did replace all the steam traps in all units. Believe it or not there were two traps that were just empty housing, no element inside! We added a larger, antlered vent on the end of the return, just before it drops down to the boiler, and we experimented with various pressure settings, low water cut-off etc. There was minimal improvement at best for me. So eventually I just accepted that I had the lemon unit in the building, and was doomed to hear the clanging and banging of the Ghost of Christmas Past every night, while my neighbors luxuriated in the quiet enjoyment of silent and even heat.

But then a few months ago pipe leaks started appearing in the business below my flat. The landlords sent plumbers to clamp them, but then they would spring somewhere else. The leaks were on my return line, which is above their false ceiling. I took the opportunity to go down there when they were working and see the return line. It was ancient, and corroded, and clearly had no slope at all. I suspected there was an awful lot of condensate sitting in there and that it was the biggest source of my problems. After many months of clamping the leaks, the plumber announced that it was time to replace the pipe. The landlords finally consented, and sent a team to remove and replace the entire return line last week, as well as a broken check valve that was also on that line just before the last leg of drop to the boiler.

The result? Crickets! Silent, even heat, and radiators that quickly receive steam with nary a bang, clang, slap or clap. The only thing I hear is the comforting sound of old oak floors creaking as the expand above the warming pipes. Success!!!

I just had to share with you all. And to say THANKS for all the sage input that helped me along the way.

Elisabeth