2-pipe conundrum in SF

JUGHNE

Yes Fred, the equalizer uses the lower left inlet return port. The actual return pipe enters on the lower right inlet. I wonder about the absence of the pressure on the top of the return water that a HL would provide.

ElisabethInSF

It does indeed enter into the boiler back there where it drops down from the header. Here's another pic if that helps.

Fred

I think the pressure inside the return itself is equalized and should be ok.

ElisabethInSF

Hi Everyone! Thought I would post a video of the water dumping from the system this morning. This happened about 10-15 minutes after the boiler started. I also noticed that before the boiler started (it's been off since yesterday morning because it's freakishly summer-like in SF right now), the water line in the sight glass was at the very top. In fact I thought it was empty because the water line was not visible at all, being at the very top. But if you look in the video the line starts to become visible as the water discharges from that exterior pipe. It's jumping up and down about 1/2" - 1". I'm hoping the video will provide some clue to you all about why this might be happening.

KC_Jones

That pipe shouldn't be there...at all. There is zero reason to dump water like that period end of story. I suspect you have a slow return piping. The condensate is taking too long to get back to the boiler. When the water gets low your auto feeder feeds water which then actually over fills the system. When the boiler starts up and starts building pressure the water backs up in the return pipe and hits that trap and then dumps all the extra water that shouldn't have been there in the first place. I suspect some crudy return pipes that need a good flushing. Also that trap and piping either need removed or the valve turned off. Dumping water like that on a steam system is a HUGE no no and anyone that has even a tiny clue about steam should know better. That is definitely a knucklehead move that makes no sense at all. The water returning slowly could certainly contribute to banging in the system. Apologies if this has been asked and answered, but in the building are you on a lower level perhaps closest to the boiler? That would be a likely spot for the water to accumulate.

Fred

@KC_Jones , There are no wet returns on this system so it is unlikely that this is caused by slow returns. As it relates to this particular problem, we have advised the poster to make sure the Pressuretrol is working and that the pigtail is not clogged, causing high pressures. I also suggested that the boiler may need to be skimmed. It actually sounds to me like that particular issue is the result of one of those two things. The water is being pushed out into the return, some of it is dumping out the drain some knucklehead installed, all the while the auto water feed is adding more water to the boiler, over filling the boiler.
AFTER looking at this latest video, I'm convinced the issue is one of a few things:
- a clogged pigtail or the stand pipe it is mounted on
- a defective Pressuretrol. I also believe the pressure is way higher than that 0-15 PSI gauge shows.
- The Low Water Cut-off and its probe also need to be checked/cleaned and maybe replaced.
The water looks pretty clean (which I guess it should since the boiler is virtually being dumped and refilled with each heating cycle. Water bounce doesn't seem to indicate an unusual amount of bounce. the need for Skimming seems less likely a fix for this.

ElisabethInSF

Hi KC,

Yes, I am on the lower level closest to the boiler. And I also experience those most water hammer and issues with some rads not heating until the system runs for over an hour and a half.

Someone suggested shutting the valve to the pipe off and watching what happens for a couple of runs with the boiler. But doesn't it need to dump that water if it's over-filling in between cycles? I'd hate to find out that it needs to happen until the issue with slow return is corrected. I have a To-Do list that is getting longer and longer, but I'm going to add your suggestion about cleaning the returns to it.

Thanks so much for your reply!

JUGHNE

Pictures of the piping on the exterior of the building may reveal some piping issues creating a wet return.

Also did you find the read out of gallons used, if so note the present reading for an idea of water consumption.

ElisabethInSF

I do not see a reading of gallons used. And the programmable water feeder is in a really awkward position. I was able to shimmy back there and saw this on the front. Clearly an error. This was taken about 2 hours after the boiler had shut down for the day. I see also that the on/off switch on top is not set to "feed".

ElisabethInSF

And the water level is back to the top of the glass! It had dropped mid-heating cycle this morning to a little under the halfway mark. So cleary it's filling back up in between cycles.

Exterior piping pics coming soon. Trying to get some of my "real work" done today :-)

Fred

Add a Auto Water feeder to the list of things that needs to be done. If the feeder is set to Off so as to not feed the boiler, clearly supply water is leaking past that unit and into the boiler, otherwise it could not over fill like it does. Those feeders have an internal valve in them that do fail and leak. normally we'd tell people to shut the supply valve, on the water pipe that feeds into the Auto Water Feeder, off so as to stop any flow of supply water until that unit can be replaced. You can then watch the water level and add water manually using the bypass valve. In this case, with that water draining to the outside, I'm reluctant to suggest that until the pressure is checked and verified and the Low water Cut-off is proven to work.

KC_Jones

http://www.hydrolevel.com/pages/pdf_files/vxt120_opt.pdf?lbisphpreq=1
Looks like whoever installed it set something wrong. See the bottom of the second page on this. This is most likely an easy fix by correcting the dip switch settings.

Fred

Certainly looks like a possibility.

ElisabethInSF

OK, here are pics of the pipes leading to and from the boiler room and building.

Fred

It would help a lot if all of those exposed sections of pipe and fittings could be insulated as well, especially since they are outside.

ElisabethInSF

I don't see where the pipes enter into my under floorboard area. Is it possible that the only entry is through my kitchen rad? Here is a pic of the return area of that rad btw.

Or is it possible that the second pipe off the supply on that rad does not go up to neighbor's apartment as someone suggested, but heads into the wall, then down under my floors? I see no other area where those under floor pipes could enter from outside. Strange.

SteamCoffee

Holy moly! Boiler issues aside, I think the roots of the knuckle heading are starting to reveal themselves. It looks like the copper pipe was spliced in LONG after the original black pipe system was installed. The end of the supply main, just before it enters your kitchen, is simply a 180 degree turn into the return main, not hard to see how steam is getting on the wrong side of your radiators via a short circuit, failed traps or not. That intersection is a likely place for return condensate to backup in the return and further flood the supply main. I noticed the copper return is reduced before it enters the insulated part of the return. I am wondering where the returns from your other rads, and from your upstairs neighbors, actually tie into the system? Is this the same arraignment on the other side of the building? If not, the original configuration might provide some clues as well. Once the boiler is straightened out, the steam, air and condensate, have a LONG round trip to make. I wonder if the Frank Geritty style master vent at the top of the highest riser wouldn't be a partial solution? Your landlord should be thrilled you are interested, the boiler is headed for a short life... The good news is your getting the very best advice available!

JUGHNE

The short circuiting of the steam main and water return looks to be a major problem. Steam and condensate water are always supposed to separated by a trap of some sort or a vertical leg containing a solid standpipe of water that the steam and air cannot pass thru. A horizontal pipe containing water and steam produces water hammer which you are painfully aware of.

Is the whole building piped this way? Outside your kitchen window (referring to the last pictures posted) it looks like 3 pipes go vertically up to the next floor. 2 of them are tied together and have the sediment drip leg with the pipe cap.
Could you clarify their function.

The extra pipe going into your wall could be the steam for the next radiator. Steam can travel in any direction. But the condensate produced as it travels thru a pipe must be dealt with to drain back or into a drip pipe connected to the return.

The return water must drain somewhere back to the return, it can even go up and back down but has to end up going downhill at some point. If there is this up/down piping then that part would be a wet return and not pass air for venting.

Does your kitchen radiator drain out the wall or down into the floor?

This steam system is probably from the original 1926 construction. It had to have worked in the past or it would have been torn out. Now when the boiler was moved (you say 1950's) problems may have started. The first 25 years may have been good, seeing how it was left in place. But the next 65 years required a lot of patience, but the system is still there.

So does the other apartments mirror your outside piping? Steam is usually piped in threaded pipe, the copper could have be more recent and imply a more recent knuckling.

If the boiler was below you and perhaps the piping came thru your floor there may be evidence of holes at the radiators....could have a wood plug or a newer section of floor there.

Or do you think the piping was always on the outside of the building? The water and drains appear to be originally there.

ElisabethInSF

Just when I finally think I am getting a good action plan together someone asks about the piping! That seems to be the elephant in the room (the rest of the suggested fixes being mostly deferred maintenance).

Oh boy, where do I begin? Let me start by saying that every service person who has come to the building during the 10 years I've lived here have all made the exact same face while examining the pipes outside my kitchen window - something between bewilderment and anger. It really makes no sense, and begs the question that perhaps when the boiler was moved some things were not done properly, especially where my unit is concerned. Which does in a way explain why mine is the loudest and most problematic. My neighbors upstairs have no issues whatsoever with noise or performance.

I can't answer all your questions, but here's what I do know.

The return pipe on my kitchen rad goes down into the floor. The supply is coming from that outside pipe in my last pictures. So it seems that return line out there is strictly for the upstairs neighbor? I see no visible connection between my rad outside, or any other pipe exiting and connecting with that return pipe heading back to the boiler. But obviously there must be a connection to the return lines somewhere, right? I will have to explore further to determine where that might be. But right now it looks like a lot of my piping is not visible.

As for if the piping was always on the outside - I suspect those older covered pipes outside my window were original, and the copper (un-insulated) extensions and the long pipes running to and from the boiler room were added when the boiler was moved. Again I will see if I can figure out where I am connected to those lines.

I will also climb over to the neighbors side and see if the connections are the same over there. Will post pics later.

I am now wondering how much good all the other work folks have suggested (replacing steam traps, figuring out if water feeder is working and replacing if not, re-calibrating pressuretrols if needed etc) will remedy much in my unit if the piping turns out to be the real source of my problems. I will say that several maintenance outfits have suggested that the only solution is to re-pipe underneath my unit. This is where the landlords shut down and said they are not willing to incur that kind of expense. There is a chiropractic office below me, and that would likely mean having them shut down while the work is done through their ceiling, which would add to he overall cost. The folks in that office can hear the water hammer going on in the ceiling by the way (which I hear under my floorboards).

I can think of no reason why there is that loop between the supply and return outside my kitchen window! Nor can anyone who's looked at it. What possible function could it serve? Do you suppose it's something that could be eliminated?

Once again, I appreciate your thorough response! Everyone has been so generous with their thoughts on this. I'm half expecting to receive bills from you all in the mail any day :-)

Jamie Hall

Good grief! I have to admit I've never seen the like... at least it's on dry land, and not one of the houseboats one sees tied up on the Bay!

It's going to be a bit tricky, but a good bit of fun really. What needs to happen, I think, is that you maybe in company with a friend or two need to figure out really which pipes are connected to which, and to what radiators in the house and how they are hooked up to the boiler, and which way they slope -- and maybe even try to make a sketch of the whole thing... !

No bill, but honestly I wish I were close enough so that I could come and take a look at it in person!

nicholas bonham-carter

When the display on the water meter shows an error, it usually means the dipswitches have been misset:

http://www.supplyhouse.com/Hydrolevel-VXT-120V-Automatic-Water-Feeder-120V-10672000-p

ElisabethInSF

Honestly it might be cheaper to have a real pro from this board come out than to find a good steam outfit out here. They do exist, but I am not finding anyone great yet. A lot of the "better" outfits only handle commercial buildings these days. If someone set up shop here there would surely have a booming business, because I can tell you there are countless small and mid-sized buildings that still have steam heat, and most of them need attention!

So I figured something out. My return line connects to the one I've been pointing out on the exterior, just past the dogleg over the side of the building. It comes out of the back wall there and goes straight into the return. It does the same on the opposite side of the building. So it seems the lower units have returns in from the kitchen rads that go under the floor, then run underneath the tar and gravel roof area and connect to the return that you have seen that runs along the back of the building, sloping towards the boiler.

So basically my returns from all radiators are under my floor boards and stay under that roof until they connect in the back, about 15 feet from the boiler. Seems to be the same for downstairs neighbor across the hall from me. Their unit is the second most problematic by the way. Upstairs folks are living in clover!

Now what? Ha ha!

ElisabethInSF

Some pics of neighbors' piping outside kitchen window (opposite side of building). As well as where I see my return connection near the boiler.

ElisabethInSF

Can someone tell me how the return lines can be cleaned? I see in the book that there are instructions for how to clean boilers, but I don't see anything about cleaning returns.

SteamCoffee

Don't get discouraged! Now that we know more about your returns, we can analyze the SYSTEM! The budget is tight, so you need bang for the buck. It seems the biggest non-boiler issue is separating the supply side from the returns. Critically important is getting steam to the farthest radiators ASAP, the faster it gets there, the faster is can condense and head back to the boiler. Lower steam pressure travels fastest, this we know, that can't happen very well with the battle between steam (headed to rads) colliding with supply/return condensate in your piping. Removing the loop looks very easy and is a win-win, it appears to be a major choke point for return condensate AND prevents trap short circuting/self destruction. Less resistance, and better BALANCE, going to and from the rads=less noise, more BTUs at the rads, lower gas costs and a much happier boiler. Once that is done, the venting strategy can take place. Then traps, then boiler issues. There are smarter people than me that can chime in on how best to do it, a 2 pipe counter flow isn't common. You have a huge amount or air to move before you get steam to the rads, and you must be able to get condensate back to the boiler in a reasonable time as well. I am sure the key to a happier SYSTEM is the piping. It seems to be the major source of your boiler chaos and added garbage attempts to fix unstable water levels. The solution isn't a daunting as it appears, you are miles ahead of where you were when you first posted. Press on! PS the upper units seem to be getting better quality steam and less interference from condensate, a big clue as to what ails your system! PPS I am guessing you have the CLEANEST dry returns ever before seen....

Fred

If this system had wet returns, (returns below the boiler water line) it probably would have drain valves or plugs in the ends of those wet returns that would allow you to drain them and flush water through them. From everything you have shown and as best as I can see, you do not have any wet returns, they are all dry returns and there is no need to flush/clean those.

ElisabethInSF

Indeed they are dry returns (above boiler).

Someone had suggested that cleaning the returns might help if indeed they are having trouble getting air out of the system, though I imagine that the venting suggestion to swap out single small vent on return in boiler room for 2 Groton's with an antler would help that, as would new traps on all rads.

Fred

ElisabethInSF said:

Indeed they are dry returns (above boiler).

Someone had suggested that cleaning the returns might help if indeed they are having trouble getting air out of the system, though I imagine that the venting suggestion to swap out single small vent on return in boiler room for 2 Groton's with an antler would help that, as would new traps on all rads.

Agreed. I think the comment about cleaning out the returns was based on an assumption that there were wet returns and that could be the cause for water returning to the boiler slowly, causing the water feeder to add more water. Not the case here.

ElisabethInSF

Why on earth would someone have installed that loop? They must have been smoking dope! There is one on the other side of the building as well, though it's positioned differently. You can see that one in the pictures in my last post with photos. It does not look like a big job to take it away so the supply and return lines can be separated. But someone must have thought putting it there did something.

My plan is to add it to the To-Do list with a note that it needs assessing by professional first.

Fred

I can't figure that out either. Just like the drain outside of the boiler room. It just doesn't make sense. I suppose before the boiler was moved, there could have been a cross-over trap at the end of the main and whoever moved it skipped the trap and just looped it back. Who knows???

ElisabethInSF

Probably a combo of cheap owners and bad craftsmen!

I can't believe how much I have learned from all this! As frustrating as this system is it's kind of like a fun mystery too.

I may go down to the library and look at the building records that should show original construction and plans and later adjustments. Who knows if what I've been told is true. In fact, looking at the records available online at the city assessor's office has already shown that the building was erected in 1922, NOT 1926 as the previous owners told me. Just found that out today.

ttekushan_3

I lurked at the beginning of this thread and decided to catch up w/ heatinghelp today to see how things have developed on this one. My have they developed! Tons of great info. No doubt a great learning experience.

The last photos are very telling. Your returns are lowest and directly pressurized by that crazy u-turn in the steam supply into the return. You have no pressure drop from supply to return! And best yet, any surreptitiously places radiator vents will ensure that any flow in the returns will be back towards your radiators.

The only thing I can think of is that there was concern over condensate freezing in the return line. I'm sure it doesn't! Get rid of the direct interconnection and drip the main through a steam trap. If there's inadequate height for a float and thermostatic then a straight pattern balanced pressure type will have to do. If freezing is a concern, that's what a steam tracer is for. You just run maybe a 1/2" or 3/8" steam line from the main where the cross connection is now and run it under the insulation, and companioned to the return that goes to the boiler house. Come to think of it, forget the interconnecting trap and use the tracer line as the drip at the existing crossover. Place the tracer line's steam trap in the boiler house where it will join the return connections above the water line, i.e., into the vented return.

Then do all the other stuff as needed. :-)

ElisabethInSF

Hi Terry,

Thanks for chiming in! I can assure you that freezing in San Francisco is a non-issue. Sure it gets cold in winter, and the temp may get into the lower 30's in the middle of the night in January, but freezing is very rare. It's 72 degrees as I type this - though that is somewhat odd for this time of year.

I have already added comments about the crossover loop on my list of fixes, but will add your additional info.

Thanks so much!

JUGHNE

Terry, San Fran design temp is listed as 38 degrees. I was wondering about freezing but a lot of DWV P-traps appear on the outside, so if it touched freezing the steam would be on anyway.

You mentioned dripping the main, this looks to be a counter flow steam main so should be no drip condensate at the high end of the horizontal main, IMO. Now the riser going up to the next floor would have some condensate, depending on size etc.

Yes, the return loop on the horizontal main and "dry"? return is a mystery.

But, in the first video I noticed outside her kitchen window, a pipe cap on a drip nipple. These last pictures are more clear for the opposite side of apt bldg. There looks to be a drip loop from the second floor return. Perhaps such as you might see in a 2 pipe rad with air vents. The steam is kept out of that return by that maybe 6-7' water trap.

So, maybe this is a counter flow--2 pipe--vented radiator--water seal for second floor system going into dry return....or if all 2nd floor returns come out each side then each rad needs a trap or a water seal like this ?? (for what we can see of the second floor, anyway)...maybe this is why the 2nd floor seems to work....but how does the air vent out without rad vents....does the second floor all have rad vents??

For lower floor, could be the counter flow--2 pipe--radiator vented thru traps...no water loop seal.....into a dry return (that doesn't have a steam main directly connected to it)

The return coming out of the wall for the lower floor, (just above the dryer vent hood), has a wye swing check valve perhaps installed to hopefully prevent steam from going from the dry return (which should have no steam in it) back into your return line which should also have not steam in it.

That check valve would close with steam pressure and might open later draining some of your water back to the boiler. It could have steam pressure on either side engaged in a tug of war to open the valve or close. It would not usually be there if all was well.

Here is what happened, the plumber was told to install a return line and he thought it was a hot water recirc system and you tie the return into the supply.....right? ...Beth, that's a joke for piping people.

If you can go upstairs to the kitchen without rad, do they still have the mystery pipe connected like yours and just have the rad removed? That pipe may feed other heaters in their apartment......if you can shut the valve off to that pipe in your kitchen then you may find out what it feeds.....maybe the rad straight across the house?

JUGHNE

Looking at your video again, the larger valve in your kitchen would shut off both your kit rad and the wall pipe. You could shut that off and see where the steam does not go. Feel the top rad inlets only, you could be getting return steam from the neighbors on the bottom trap pipe.

Also, have we seen all the entry points to the building for steam supply and returns? The other half may have the same back wall return pipe that you do. But does the steam piping go in and out at any other points? There could be a tee hiding under the insulation with pipes going thru the back wall. Might see them bettor on the right hand half of the back wall.

SteamCoffee

The upstairs neighbor may be a good place for a vent or two! Btw look around at your surrounding neighbors exteriors, you may see a very similar set up. In my part of SF one developer built the all the housing, circa 1923. I am reconstructing my steam system by being a nosy..I still have the original building permit. Btw what part of town are you in?

ElisabethInSF

The entry points on the other side of the building appear to be identical to those on my side, both for lower and upper units. I did dig around a bit with a flashlight this eve and cannot see anything that doesn't mirror my side of the building. Thankfully we are all friendly here so no one was alarmed by my nocturnal rooftop explorations.

I visited the neighbor above me as well (a nice Scottish chap), and he let me have a look around his flat. Definitely no rad in the kitchen , and since there is counter and cupboards there now, there is no visible sign of a capped off pipe from the interior that I could detect, even from inside the cupboard. But from the outside you can see clearly that one enters exactly where his kitchen rad used to be.

As for venting on his rads, he as them on the same two that I have them on - living room and bedroom, which are the two furthest from the boiler - but no vent on the dining room rad (also same as me). The upstairs neighbor on the other side has vents on all rads except the one in the kitchen. I cannot speak for the lower unit on that side, as I've not been in there and know those folks the least. But they have the same entry pipe as I do below the kitchen window.

Not sure if any of this information is helpful.

SteamCoffee

I wonder then, how your upstairs neighbor gets steam the other rads? You said the only (known) entry point for steam is at you kitchen? That could explain the 2 pipes at the handle, it also appears you have another valve, sans handle, upsidown on that rad? It would be nice to know what is going on under your floorboards, i.e. Counter flow/parallel flow to the rads at the far end of your unit? I just noticed the check valves on your returns at the back of the building, yet another place to back up massive amounts of condensate. Probably a major contributor to your boiler water level? It cycles, steam goes out, water level drops, return condensate trapped by pressure against the check valve, water feed goes on, boiler fills, boiler cycles off, check valves opens, a deluge if condensate floods boiler.....ughhhh! All the venting on rads were the cheap $$ attempt to get steam to the rads in a choked off system.

ElisabethInSF

Hi Steam Coffee!

This gets a bit tricky to explain, especially because I am likely not using the correct terms, which forces everyone reading to interpret what they "think I mean." It could get murky pretty fast!!! But I will try to explain what it appears like to me.

From what I can see outside the building on both sides, and from what I know of the boiler having been moved from underneath me to that shed behind and away from the building, the supply for the downstairs units has one entry through the kitchen radiators. That second pipe that goes into the wall there may be where the steam entering drops down under the floor and heads out to the other rooms/rads. I can feel the swollen floor boards that go under the doorways from the kitchen all the way to the furthest rads, and of course hear a lot of hammer originating from the floors, so clearly that's where the mains are in my unit. The return also appears to run under the floor (parallel I assume), and joins the visible return line at the back of the tar and gravel roof area, that was added to accommodate the businesses below at the time the boiler was moved. The upstairs folks have two entry points into their unit. One that goes directly to the kitchen rad, and a lower one that is likely the main that jams along under their floors. Their returns become visible on the exterior of the kitchen area, drop down and travel on top of the tar and gravel roof area, before mine join past the dogleg over the edge and head to the boiler.

I will make another video that is more specific to this in a while here. The first video that gave the full tour was based on my not knowing anything. Now that you all have give in me some explanation I can zero in on more useful imagery.

I am in the Outer Richmond by the way. Where are you?

ElisabethInSF

I woke up too late this morning to do it before the heat turned on, but I'm going to shut off the kitchen valve later to see if it stops heat from traveling to the other rads this evening. If it does do that, then we know that the second kitchen pipe is where supply drops down into the under floor piping, and gets heat to the other rads.