2-pipe conundrum in SF

ElisabethInSF

Dear Heating Help Pros,

I am looking to get some advice on a problematic 2-pipe steam heat system in my apartment building. I will attach some videos to help you visualize (and hear) what is going on, and will do my best to provide information that is helpful.

Some background. I live in a 4-unit apartment building in San Francisco that was constructed in 1926. All apartments are the exact same size and layout, so locations of all radiators is the same in each unit, with the exception of the unit above me, which had one one rad removed when they remolded the kitchen (they now have 3 rads and all other units have 4). There are 2 apts downstairs, and 2 upstairs. When the heating was installed back in 1926 the boiler was located under the building at street level. That area was later converted for commercial/storefront use, and the boiler was moved to an exterior shed behind the building. I will include a video tour of the boiler room and the pipes leading to and from the building.

For whatever reason my apartment is the steam heat lemon of the building. While the other three apartments enjoy relatively quiet rads that heat evenly and quickly, my rads and pipes make a tremendous amount of hammer noise, as well as various other odd sounds, and they take much longer to heat, and in some cases don’t heat all the way (top warm, bottom cold). After years of complaining to the landlords I’ve been told “tough luck” the system is old, deal with it. The only solution offered was to disconnect me from the system and install (gasp!) electric wall units. Clearly they have no interest in maintaining the integrity of this older building, and want to spend as little as possible. However, they have told me that I am welcome to find a solution on my own and that they might pay for the work, as long as it does not involve ripping up floors or ceilings and installing new pipes. So I’m hoping that’s the case. I grew up in a house with steam heat, and think it’s the best thing since sliced bread. So I want to do whatever I can to remedy the situation.

Our heat runs on a timer, and there is also a thermostat in my upstairs neighbor’s apartment. It’s set to run during a 3 hour window in the morning and 2 hours in the evening. It will go on and off during that time depending on the thermostat temperature reading (usually 72 degrees). When I first moved in 10 years ago we had no thermostat (we installed it ourselves), and the boiler ran at full power during timed cycles. The apartments were baking hot, it was loud in every unit, and heat damage started to appear on the walls and floors near the rads. The boiler was running at very high pressure, and it was generally a very poor set up. Thankfully my neighbor was able to chase some wires and figure out how we could install a thermostat. The boiler has also had some work in recent years - an automatic water feeder was added, new insulation was put on pipes, and the angle of the exterior piping was adjusted for optimum flow. It has made the system more efficient, cost-effective, and silent for the other three units. My apartment continues to clang and bang however.

Here’s a description of what I experience. When the system starts up for the first 20 minutes I hear minor tapping and creaking sounds under the floor boards that sound like the wood warming and expanding. Nothing major there. Then there's some gentle clunking for about 10 minutes. At this point the only rad that feels warm is the one in the kitchen (closest to the boiler). All others are ice cold, but I do hear hissing from the two that have external air vents on them. About 30 minutes after start-up I hear a loud click-slap, click slap at the point where the main pipe enters my apartment, and the first riser to my kitchen rad connect. That lasts about 10 seconds. From there the different rads will make all kinds of banging, clacking, rattling, slapping and water gurgling noises, even though they are not warm yet. Something to note: the two rads that are furthest from the boiler have exterior air vents installed on them.

I have lived here for ten years and at no time has any service been done on the radiators themselves. No replacement of valves, steam traps or cleaning/flushing has been done. They service the boiler once a year, and act like that’s all that need be done ever. I have suggested to the landlords that perhaps there are bad steam traps and they should all be replaced, but they balked at this suggestion. Two days later they had a guy out to measure for installing electric wall heater units!!! They are convinced that nothing need be done at the radiator level, and that any problem has to do with incorrectly pitched pipes under the floor boards due to age and building settling (read: expensive work to remedy). While this may be the case (the amount of water hammer I hear from those pipes has certainly given rise to the suspicion), I’m having a hard time imagining how that would cause radiators not to heat, or cause metal rattling sounds inside the rads, or any of the other problems I’m experiencing. I also hear what sounds like water being pushed along the pipes, and liquid gurgling inside the dining room and living room rads.

The interesting thing is that with all the noise and lack of heat for the first hour or so of the system running, eventually my rads figure it out and do get warm. But again, it’s with tremendous noise, and it happens much later than in any other apartment.

I have included some videos below. The long one is a video tour of the system, then there are several of the different noises I hear. I’m happy to take more pictures or answer any questions.

I appreciate any wisdom you can throw my way. Thanks so much!!!

Links here. I hope they work:

System tour:


30-min post start-up:


Mid cycle dining room Rad


Mid cycle living room rad:


Mid cycle bedroom rad:


Under Floor boards hammer:

Abracadabra

There's so much to discuss here I'm not sure I'll be able to cover even a small amount. There appears to me to be quite a bit of knuckleheading that has been performed on this system. Just from a quick overview of your videos.

• The pipes that lead from the boiler to the main building that go outside appear to me to have a sag in the middle. They are not supported along that outside run. This will trap water in the main and cause hammering.
  
• The steam vents that have been installed on the radiators appear to be a kludge fix for failed traps or an attempt to get more venting done at the radiator? Not sure. 2-pipe steam you don't need vents at the radiator.
  
• I noticed a small radiator vent on the return? in the boiler room? That vent, if it's for the entire system, is a joke. You need a lot more main venting.
  
• I believe I also saw uninsulated copper lines outside. That's a no-no in more than one way.
  
• The trap that discharges outside is a kludge. If it's discharging a gallon or so of water each cycle, that boiler will have a very short life.
  
• Anything over 1.5lbs/sq.in. on the pressure gauge is a waste. 4 is ridiculous.
  
• I don't see a relief valve.
  
• I see where you showed two pressuretrols. The one control is grey and I think you say something like "it's close to the bottom". The other has a clear plexiglass front cover. That looks like a manual reset pressuretrol. If the boiler is reaching 4psi, we need to see what the little white dial inside the grey control is set at. You need to take the cover off the grey control.
  
• At about 5:20 in your first video you indicate a pipe with a sag. If that's a main or dry return, that sag will cause condensate to be trapped and cause hammering. In addition, with the amount of sag that's visible, the pipe may actually be completely full of water, thereby blocking any venting which should be occurring back at the boiler where the return drops down.
  

Like I said, I see so many issues, you really need to have someone on site to discuss with the owner.

Jamie Hall

@Abracadabra has pointed out most of the easily visible problems; there are, undoubtedly, others.

The good news is that there is nothing there which is not fixable, and not at all that much expense, either -- even correcting sagging pipes isn't all that hard to do.

The bad news is that you really need someone who knows what they are doing. Last I looked there weren't any Wallies in the San Francisco area... however, there are good plumbers, and there is you, and you are interested -- so there's hope. Most steam system repairs are pretty much a combination of persistence and common sense.

I would suggest, then, that you get yourself a copy of a couple of the books in the bookstore -- "We Got Steam Heat" and "The Lost Are of Steam Heat". Between the two of them, and some poking around, you should be able to figure out how the system was supposed to operate, and then how to get it back there.

And we welcome questions!

Fred

As Abra has said, most likely those rads with vents on them have traps that are failed closed. The other rads may have traps that are failed open, allowing steam into the returns and causing hammer when that steam hits the return water. There is definitely a huge sag in that one return pipe (maybe the other pipes as well but the one is most obvious). That sag needs to be corrected as it allows water to pool there and if any traps are failed open, that just compounds the hammering.
Your radiators should have a little pitch to them so that water can run drain out through the traps (if the traps aren't failed closed). You can shim the far side of the rads maybe a 1/4".
The mains need a lot more venting on them. That little vent above the boiler is virtually nothing and a lack of main venting means the steam has to push all the air out through those radiators, which simply isn't going to work with that much mains. It will take forever. The drain pipe that is just outside the boiler room is so wrong. I can't imagine what problem that were trying to fix with that solution. It will just cause the boiler to require more fresh water with every heat cycle and rot the boiler out. Much needs to be corrected!

vibert_c

@ElisabethInSF
Welcome !
This is best presentation I have seen in 18 months on this forum. Congratulations.

Alan (California Radiant) Forbes

I'm in Berkeley, but don't know steam that well, especially 2-pipe steam.

Here is my list of contractors that work on steam systems. These aren't recommendations, just contractors that I've become acquainted with when I see them at my supply house.

L. J. Kruse (Berkeley) (510)644-0260
Cornelli Company (415)252-1800
D & R Plumbing (415)626-1644
REM Boiler - Rich (650)758-1825
Superior Mechanical Services, Livermore (925)456-7200
C. R. Reichel (415)431-7100

Best of luck!

ElisabethInSF

My goodness, thanks for all the detailed responses. While it's disheartening to hear that it's a morasse of problems, I'm glad no one said to just accept the landlords offer of electric wall units and call it a day. I love my steam heat!

So to tackle one of your primary comments. I traced the pipes from the boiler room into that spaghetti mess and found that the sagging pipe is a water pipe, not part of the steam heat system. The supply and return pipes do not sag at all (though my wide angle lens made it look that way no doubt). So that part is good news.

Additionally the feed and return pipes are indeed insulated, with the exception of the last foot or so where it enters my apartment. I imagine adding insulation there would not be too difficult.

Obviously removing all the exterior air vents on the rads and putting in new steam traps in all units is not cheap but doable. The landlords are ok with something on that level. Their only push-back was on getting beneath the floors in my unit, or going through the ceilings of the offices below me. Hopefully that won't be necessary.

I do have an additional question based on your responses. If the system is a knucklehead cluster, improperly vented on the returns, and loaded with knucklehead fixes then why are my three neighbors not experiencing the problems I am? Everyone else says it works fine and is only loud when it runs for hours and hours in winter. But it's still quieter in all the others apartments than in my place.

Oh, and lastly, what's a "Wallie"?

Thanks again for your responses.. I am determined to get to the bottom of this!

ElisabethInSF

Forgot to mention that I got a copy of Lost Art of Steam Heat. That's how I learned what little I know, and found this website!

BobC

Failed traps coud be an issue can you measure the difference on each side of the trap (one side should be steam hot and the other 20 degrees or more less hot -a foot away from the trap)

There might be something different in the piping between your unit and the others, try to compare them and don't trust your eyes - use a level if possible. All of the piping should slope back towards the boiler (or a drip) so any water can drain back. If steam comes across sitting water it can hammer,

A "wallie" is one of the members of this board, there is a lot of expertise in the collective group.

Bob

Sailah

Elisabeth,

Those look like Hoffman 8C traps? How many radiator traps do you have?

If you send me your address I'll send you new internals for your traps. They are dead simple to change, you just need a few tools and some knowhow.

That should eliminate at least that variable.

Peter

Sailah

Ok after further review I am now thinking they are Hoffman 17C 1/2" traps...

nicholas bonham-carter

Wow what a response!
I think if your control system did not use a timer, it would be better. As it is the system is playing catchup every three hours. If the thermostat were a steam rated, and set Honeywell, set for a lower constant temperature, the boiler would run shorter periods of time more frequently.
I am sure we will see from more pictures that the pressure has been much too high, to compensate for the lack of venting. The air has to be allowed to escape with very little resistance, so the steam can enter.
These systems were originally designed to be Quiet, Confortable, and Fuel Efficient. Later repairs by untrained personell have made them noisy gas hogs!
Soon you will join Vaporvac, Radiator Ranger, and other ladies her whose knowledge rivals that of the pros, and can give confidence to others suffering the same problem!--NBC

JUGHNE

Elisabeth, so review the trap replacement procedure in Dan's book. They all need to be changed at once, all16 of them for the entire building. You have one rad not heating because of steam in the return getting the trap hot enough to close. So good of Sailah to offer parts.

You have some traps that you can hardly see. I encountered this in a schoolhouse and cut the sides of cabinets open for access. The simplest approach was a 1/2" drive impact wrench, lot of extensions, and the correct 6 point socket. All can be rented or borrowed. That gets the cap off, once inside then a smaller socket for the element is needed. But read the part about bad traps killing the good (new) traps.

As the steam main pipe and the return pipe approach the building and wrap around it, are they both sloped to drain back to the boiler. That is, are they parallel to each other for the most part. Not opposing slopes?
If so you may have a 2 pipe counterflow system, which may not be described in the books. (maybe someone has mentioned this already?)

Sailah

As @JUGHNE mentioned, if you have a leaking trap that bleeds down to the condensate return line it can cause problems in terms of testing or masking of good traps. I'm not totally convinced it would close off a working trap although I suppose that is possible. I might have to test that idea next week.

While I would agree with replacing all the trap internals at the same time is the prudent decision, I don't believe it's necessary at this point to determine if we can get you closer to a warm house.

The 3 traps outside your kitchen look easy enough to tackle with a simple wrench I can send you. The kitchen radiator will certainly involve an adult beverage or 2 and some mild cursing.

The closest hex size for a Hoffman C cover is 1 7/16" and you'll need a socket that size ($13 amazon prime). If you know a mechanic with a really heavy duty impact driver with a 1/2" anvil that's what I would try first. Or you'll need about 3' worth of 1/2" socket extensions, a 1/2" ratchet and possibly a breaker bar or cheater pipe.

Start with replacing the easy ones first, if that gets you heat, then you know what the next steps are with your landlord.

JUGHNE

After looking at video again, I think using the extension on the kitchen could be done from above. To get the old element out might require a little more caution....was that a 3/4" size on the inside?
I used a 18 volt battery impact, very handy, the socket if I recall right was a 6 point 1 1/2". If you got one cap off and took it to the rental store for sizing then you know......(boiler off for this of course).

Sailah

Yes the Hoffman seat is a 3/4" hex. So you'd need that too but any socket set would have that.

The cover hex is 1 7/16" I just measured one. 1 1/2" is kinda sloppy fit.

In my experience and working with steam trap surveyors, anything short of a Snap On/Milwaukee "Fuel"-type 18V impact used for lug nuts is woefully inadequate for cover removal.

We put all our covers on with a 1/2" air impact and Maria zips them on pretty tight.

I've found that rigging too many extensions together acts like a torque stick with an impact wrench and it doesn't work well.

JUGHNE

The Milwaukee standard 18 is what worked for me. 3'extensions are probably rentable. Warning to not use the impact to install the element. And start everything back together by hand.....ratchet on element.....maybe impact on cap. But both have fine brass threads.....easy to cross &^%$*.

Don't forget the 1/2 X 3/4 drive adaptor for the socket. There are only 3 kitchen rads?

ElisabethInSF

Hi Everyone! I am learning so much from your responses.

Based on your comments my plan of attack is as follows. Please let me know if you think this is a sound plan.

1. Adjust the pressuretrol to a lower setting.

2. Replace steam trap innards. My upstairs neighbor replaced all of his once and has all the needed tools. And he offered to help for a 6-pack! I think that's a fair deal :-)

3. Shim the boilers slightly so they lean towards the returns.

4. Get someone out hear to check the exterior piping to make sure the angle back to the boiler is corrected.

I went down to the boiler room this morning (about 3 hours into the cycle) and noticed the pressure was at 3 psi. I'm attaching two pictures of the pressuretrols so you can see where they are set. One is on the lowest setting, the other is set between 5 and
12. That seems high. Do you think adjusting it to a lower setting is a move in the right direction?

On visual inspection I can see that the supply and return pipes are pretty level during some shorts sections leading to and from the boiler. They are pitched downward for long sections, but overall I can see that they are not consistently pitching down toward the boiler though. This is not good! I am assuming that adjustments can be made there to help achieve a proper flow along the mains. I suspect when the boiler was moved to this exterior shed back in the 1950's it was not done properly. Many of the "fixes" since then were not addressing this root problem, but were more like putting a bandaid on a cancer.

I am really enjoying this project! Thank again for all your sage advice!!!

Fred

I'm also guessing that second pipe at the valve in your kitchen, probably goes into the wall and up to the radiator in the upstairs kitchen to feed that radiator. Steam will take the path of least resistance and that pipe may be that path, at least until that radiator is filled. especially if that upstairs radiator trap is failed open or yours if failed closed???

ElisabethInSF

Hi Fred,

I think you are right. But my upstairs neighbors removed their radiator when they remolded their kitchen, so the pipe is a ghost at this point.

Fred

ElisabethInSF said:

Hi Fred,

I think you are right. But my upstairs neighbors removed their radiator when they remolded their kitchen, so the pipe is a ghost at this point.

That's a good thing. At least that won't be an issue at this point.

BobC

The pressuretrol that is set hgh is probably just a safety backup unit that will act if the low pressure unit fails. Take the cover of the low pressure pressuretrol and make sure that dial is set to 1, no need to run over 2PSI in a steam system (and hopefully less).

Keep in mind your pressure gauge might not be accurate at the low end of the scale and do you know if the pigtail under the pressuretrol has been cleaned recently? They should be cleaned because they get gunked up over time.

Bob

Abracadabra

Abracadabra said:

• I see where you showed two pressuretrols. The one control is grey and I think you say something like "it's close to the bottom". The other has a clear plexiglass front cover. That looks like a manual reset pressuretrol. If the boiler is reaching 4psi, we need to see what the little white dial inside the grey control is set at. You need to take the cover off the grey control.
  

ElisabethInSF

Took off the cover and it's set to 1. That is assuming that when the "1' is facing toward the box cover that means that's the setting. It's not entirely clear which way the dial should be turned to select your setting, and the dial just glides around, but doesn't have an arrow indicating selected setting, not does it make a clear-cut click as it moves between the numbers. Lame. See pics.

Interestingly, when I went down to do this I noticed an odd sound coming from that pipe (King Kludge) that runs off the return and discharges water outside when the system starts up. I never noticed this before (though I haven't exactly hung around near the boiler room for **** and giggles much). I've attached a video to give you an idea of the sound. The system was on for a while recently, but is in between firings (it's a balmy 65 degrees in SF, so it's not running much tonight). It had already expelled it's usual water when it fired up about an hour ago. Now this odd sound.

Kludge Pipe sound:

DanHolohan

This thread is gorgeous. Thanks to all of you.

Fred

Yes, the Pressuretrol is set correctly at a Cut-in of .5 PSI (front scale) and a Differential of "1", (inside wheel) for a Cut-out of 1.5 PSI. That sound, from that pipe sounds like air being pushed out of that pipe. As has been said, that pipe should not be there, at all but being that it is pushing out some return water, you would expect it to push air out as well.

ElisabethInSF

How does it happen that the pressure gets up to 4 psi at times if it's set to 1?

BobC

Either your gauge is funky or the pigtail under the low pressure pressurestat is plugged up. Do you know if the boiler ever shuts down on pressure? If a pressuretrol trips the boiler shuts down and then restarts in a minute or so when the steam pressure collapses.

Bob

nicholas bonham-carter

I wonder if that outside pipe was someone's idea of a vent for the system. When the pressure rises, it overcomes the trap and pushes out some trapped condensate.
I think you may be on your way to a new vocation!
Reading this article pus the costs of some deferred maintenance into perspective as far as rental income to cost!--NBC

http://www.theatlantic.com/business/archive/2016/02/super-bowl-san-francisco/460074/?google_editors_picks=true

ElisabethInSF

So I will add another task onto the to-do list here - opening up the pigtail to see if it's clogged.

I do think that funky exterior pipe is a venting attempt. As everyone has pointed out, the return lines do not have enough venting along them, so maybe they added this for that purpose. It's probably pushing out all the resting water (and air) from the returns when the boiler starts up. It seems like more and more water recently, which is not good. Used to be a small amount, now it's several gallons in the first 15 minutes of the system running. There is a steam trap on that pipe, inside the boiler room, just off the main return. That trap must close once the hotter condensate starts running back to the boiler when the heat is on, which explains why no water comes out except at start-up.

Can anyone offer some pointers on adding more ventilation on the returns? I'm sure it's covered in the book, but if anyone has any watchwords and advice I would sure appreciate it.

I think I'm as obsessed with steam heat right now as everyone else in this town is about the Super Bowl!

nicholas bonham-carter

The system pressure should be kept even lower than the winner's football!--NBC

Fred

Venting on a two pipe system can vary depending on the type of system that is there and where any cross over traps might be, between the mains and the returns. You note one in the boiler room. Are there any others? Lots of guys here, @Jamie Hall , @Steamhead , and others are great sources that may be able to guide you on the amount and type of venting you need once they understand how this system is set up. In the mean time, I'd suggest you or someone inspect that pigtail, under the Pressuretrol and make sure it is cleaned out. Keeping the pressure down will help the system immensely and maybe even reduce some of the banging. When removing the Pressuretrol, use a wrench to turn that hex fitting that is screwed onto the pigtail. Don't take the screws out of the bottom of the Pressuretrol or try to turn the Pressuretrol by hand. Twisting the Pressuretrol case will ruin it. If the Pigtail is open, we can provide you the instructions to recalibrate the Pressuretrol but let's clean the pigtail first.

JUGHNE

Could you post some still shots of each side of the boiler, showing all 4 sides including the top? Also if you can go outside your kitchen and show the piping where it goes thru your wall and the next floor above.

ElisabethInSF

Here are pics of the boiler from different angles. I will go outside shortly and take some pics of the pipes outside my kitchen and up above at the neighbor's.

One strange phenomenon happened this morning. No water discharged out of the funky pipe as the boiler started up. I went inside the boiler room to check on the water level through the glass, and it as halfway up the tube. The other day, and on days when it does discharge, it is almost at the very top of the glass. Could this explain the mysterious water dumping? Hmmm.

As I was taking these pics I noticed a pipe I had not seen before. It was slightly hidden underneath the water feeder. It runs directly out from the boiler bottom, and outside, where it sits next to kludge pipe we've been discussing. It has a shut-off type handle on it. I've never seen any water emerging from this little guy. I've included a picture of it in case it means something to you all.

Fred

That pipe from the bottom of the boiler that goes to the outside is just to drain the boiler to flush it out or when any other maintenence is done where the boiler has to be emptied. That is ok. The other outside pipe where water drains with every (most) heat cycles is just wrong. It looks like it is at about the Normal Water level of the boiler and may have been an attempt by someone to address a boiler that was over-filling, maybe because it needs to be skimmed or it may have been someones attempt to add a "Skim Port" which won't work that way. I see it has a trap on it too so I don't know what they were thinking when they installed that. I do, however, see that there is a shut-off valve on that pipe, just before the trap. It is possible to shut that off and that pipe will no longer drain water. While we don't know why that was installed, it is possible that it was intended to be closed and that someone forgot to close it. As the Landlord about it. I would shut it off and watch the boiler run for a cycle ot two and see if the water in the boiler remains where it should be or if the boiler shuts down on low water and the water feeder adds water. If it does, watch the boiler when it is idle and see if the water level has risen. Also, watch the boiler sight glass and see how much the water bounces. If it bounces more that more than 3/4", or if the water drops very low and then fills back up immediately after the heating cycle,the boiler may need a skim. If so, once it is skimmed, that valve can be left in the off position. Anytime piping or other work has been done on a system, that can add oils to the boiler water and cause the water level to become unstable. The boiler should always be skimmed a week or two after piping work has been done.
Venting is still a big issue. I would start by adding 2 Gorton #2 vents, on an antler, right where that small vent is now.

Alan (California Radiant) Forbes

That lower pipe is a drain, to be used when you want to empty out the boiler or for flushing purposes. The valve is in the off position and should be left that way under normal operation.

JUGHNE

My guess is that you have a 2 pipe system that is a counterflow.
The only one I've seen is not far from me, (though I have not seen a lot of steam systems), I have never seen one described in any book. Maybe they are fairly common?
Simply put; to describe the one I am familiar with:
the steam main and returns have their lowest point at the boiler. (like yours). Both pipes then slope up and away to the radiators. (like yours). There can be no dip, sags or jump ups and back down (maybe not like yours). There are only traps at the radiators.....no air vents on rads.....main venting is at the return where it drops down to the boiler.....(yours way too small to vent all air from steam main, thru rads, and thru return pipes).

There was no connection between the supply and returns other than thru the radiators. The rad traps separated the steam from the return water.

It sounds like you have delayed return of water to the boiler. While the boiler is steaming it automatically adds water because of the delay of returning condensate. When done steaming the water flows back flooding the boiler. The knuckle pipe looks to be just above the top of the sight glass and might drain that excess water when off (maybe unnoticed). Water may not all drain back because of sags or trapped by vacuum in piping. When steam comes again then that pressure may push the hung up water thru and that is what you see coming out.
If that is just an ordinary rad trap on the knuckle it should be open until it feels the temp of steam, as the intent of a rad trap is to pass air and water and close for steam.

It is surprising that you have a drop header using both risers out of the boiler.....whoever did that had some awareness of the value of that set up. You have no Hartford Loop as counter flows don't have. Your equalizer is connected on the lower left of the boiler and your return is on the lower right side. They also added a check valve (on the top of the right hand riser, brass gizmo that has the open pipe headed to the floor).....hoping, I believe, that that would open and break a vacuum formed in the boiler when steaming stops. That should let air into the steam main and let the water drain back easier to the boiler thru the returns.

It looks like there is a digital water meter read out....the black box on the wall to the right of the boiler. If there are numbers showing, make a note of the reading and look again in a couple of days. This may show how much water is added to the boiler by auto fill.

Your rad traps might close if a bad open trap lets steam in the return pipe. One of your rads does that....cold rad with hot return pipe below the trap. That rad could be full of water and then open to drain at some random time.

IIWM I would: 1. Clean the pigtail under the switches, and be sure the pinhole in the bottom of the switches is clear. Those unscrew with a wrench.....as warned do not remove the 4 screws on the bottom.
2. Add a pigtail with a tee fitting where the existing gauge is and add a 0-5 PSI gauge next to it on the tee.
3. Change all the trap elements on the same day , especially if they are priced right by Sailah,
4. Add the Gorton air vents as mentioned above.
5. Clean the "drip legs" on the outside of the building, the 4-6" nipple with the cap on the bottom. They could be full of sludge and impede the flow of return condensate.
6. Correct any dips in the main and return piping that you can see.
7. Keep the pressure as low as you can possibly adjust it to.

jumper

JUGHNE said:

My guess is that you have a 2 pipe system that is a counterflow.
The only one I've seen is not far from me, (though I have not seen a lot of steam systems), I have never seen one described in any book. Maybe they are fairly common?
Simply put; to describe the one I am familiar with:
the steam main and returns have their lowest point at the boiler. (like yours). Both pipes then slope up and away to the radiators. (like yours). There can be no dip, sags or jump ups and back down (maybe not like yours). There are only traps at the radiators.....no air vents on rads.....main venting is at the return where it drops down to the boiler.....(yours way too small to vent all air from steam main, thru rads, and thru return pipes).

There was no connection between the supply and returns other than thru the radiators. The rad traps separated the steam from the return water.

Steam is wonderful in that it can work many ways. For example one pipe with both down feed and counterflow up feed. Counterflow works well when done correctly.

ElisabethInSF

Wow JUGHNE! I was compiling a To-DO list from everyone's responses, but you just made the task a lot easier, and contributed a few things new things as well that make sense to me. This is truly awesome!!!

I'm glad you mentioned that a counter flow set-up would not need the Hartford Loop. I was a little panicky when I inspected down in the boiler room and did not see one; the importance of it having been drilled in my head by everything I've read so far.

I am going to post some pics of the outside piping where it heads into my apartment this evening. These last images should help close the loop in terms of feedback from the Wallies :-) Then it's all on me to get crackin'. Well actually I have to crack the landlord first.

A huge thank you!!!

JUGHNE

The typical counter flow would not have a return line such as you have to connect into the Hartford Loop. I think you could have a HL being how the return is there. However with the dry return that is there at that height I can't see the danger with loss of water from a pipe leak.
As i think out loud, without the equalizer pressure pushing on the return line, will this back up the return water, losing the boiler water into the returns???.....someone else should have some input on this???

Fred

@JUGHNE , I think there may?? be an equalizer there. If you look at her pictures, you can see an insulated pipe that appears to drop down at the end of the header, after the Main Riser and looking at the very last set of pictures @ElisabethInSF posted, it looks like that drops down and enters the boiler, below the water line at the back of the boiler, by the Pressure Relief valve. Elizabeth, can you get a better picture of that pipe? Maybe from the other side or looking down on that end of the header?