New Thread - East v West Balancing

bvaughn76

I've done a test and my homework.

I removed the air vents from the East Main and Used them on the West side. I expected that the air would now "get out" of the East much slower, giving the West a chance. Not even close. From cold system, I fired the boiler and steam started entering the header. In the header are two take offs, one for east and one west.
The east (pic left - pipe coming at you) started getting hot, the west (pic right) stayed cold. Shortly thereafter the returns from the east were hot and the first elbow of the west run was still only warm to touch. I'm lost. The west side is way shorter than the east and had main line vents. Why was that still cold and the East flowing? Easily another 20min before the west side heated up.

At this point I noticed condensate dripping out of one of the vents on the West. I busted the vent when installing it, however I should not have water up that high for sure. I looked at the boiler and noticed the water level was high. So, I shut everything off and let it cool, while I fixed some of the leaks I had on the West side and replaced the air vent. I saw the water level after cooling was above the sight glass. I wondered if that had way too much water in the system and maybe my drains were full? I skimmed the boiler to get the water level back to the water level mark on the boiler.

With everything back together, fired the boiler back up. Water level looked good, but after the east side got hot again, water level was dropping on the glass and then the LWCO turned off the boiler. Autofill kicked in, boiler restarted, steamed a while, then LWCO again, no autofill, just condensed and refired. LWCO kicked in again and then autofil. I want to say it cut out one or two more times, and then stayed running. After a long wait, got steam on the West side. However now the glass is full of water. I warmed up the house and then turned the stat down while I did my homework.

After I did my homework and while I type this, I am letting it run again. Before the boiler started, the sight glass was totally full. I heard air flowing out of the radiators on the East main. Then the boiler cutout again. I am hearing the boiler short cycle again and again.

So, like I said, i did my homework. I calculated the lengths of all the mains and then the cubic feet. They are not long and they do not have much volume. The East side "T's" north and south. I have no idea how to add a vent to the north end without busting up some really old pipe.
West total is 0.75 cuft
East total is 1.18 cuft
I can't imagine needed more than a couple Maid O'Mist #1 vents on the end of the West or East, right? I had 4 on each end.

I also calculated my radiator EDR to figure the cu ft in each of those as well. I also calculated lengths of the feed from each main to the radiator. See the table. The results were not as obvious as I expected. I calculated the minutes to evacuate air from the radiators based on the vent size. Do I want all of these to match? Or do I want the West side to be faster than the East since I can't get steam on the west. I have no idea where to start here with the venting.

Also, on the main air vents.... My mains run tight against the joists. I do not have room to stub up 10" to the vents. Does anyone have a diagram that shows some good details on how to pipe the air vents?

Updated piping diagram



Radiator Table



Original Post with pictures: https://forum.heatinghelp.com/discussion/175368/single-pipe-steam-balance-issue-one-main-vs-the-other#latest

acwagner

Let's focus on why your LWCO is flooding your boiler.

Can you post more photos of your near boiler piping? From the posted photo is looks like you header slopes down, loops back, then up hill to the two take offs, and then to the equalizer?

What's your pressure gauge doing while it's running?

ethicalpaul

I'm with @acwagner -- forget the venting until you figure out why your boiler is flooding. Do you think it was flooding before? I don't remember reading about that. That could certainly keep steam out of part of your system, if it's flooded with water!

Gsmith

Where are the high points on your steam mains? Are they counterflow (high point at the far end), it sure looks like the one on the right might be.

But I see in your picture 3 vents on what look like drops from dry returns to the wet return near the boiler. ThT will work, and it looks like you have room for larger vents there, either Gordon #2 or big mouths look like they would fit.

Are you sure the problem main does not have a low point somewhere along it that could block the steam.

Alos check that the wet return of the problem main, where it drops below the boiler waterline is not blocked or plugged.

Are there any valves on the mains or wet returns?

gfrbrookline

Agreed on addressing the boiler flooding first. Curious that it happened after changing the vents. Are they closing? Do you hear a click or do you see steam escaping from the vent? This could be your issue if it didn't happen before.

Once that is corrected.....

As for the east side still heating faster what are you using for radiator vents? They may be too aggressive and acting like small main vents. You shouldn't need anything larger then a Gorton 5, or Hoffman 40. You need to have good quality slow radiator vents.

For the main venting, I did the math on my system and I should have been fine with a Gorton No. 2 on each of my dry returns. I couldn't get my pressure down until I installed 3 big mouths on both of the dry returns on the slow side and two and one Gorton No. 2's on the two dry returns on the fast side. I am now running at 7 oz. before the radiator vents close. Heat is very well balanced and the boiler run time is about 5 min less per cycle. Every system is different so you can't always go by the math.

Steamhead

I bet your return line is partly plugged- that's why the water level drops when the boiler is running, causing the feeder to feed, and when the system shuts off the water slowly comes back, flooding the boiler.

gfrbrookline

Your previous post showed the Maid O Mist main vents in the wrong place, they should not be inline with the main on a reducer so the vent is at roughly the same height as the main.

On your systems the main vents should be near the ends of your dry returns. You have two chrome main vents in picture 1, those are your main vents. Not the ideal location, should be set back 18" but it can work. It looks like you can put a nipple on there to raise them up, do this as high as possible and add more main venting as I said above.

Plug where you have the MoM's, it's the wrong place and is likely the cause of your overfilling issue.

bvaughn76

Thanks for all comments.

@acwagner said:
> Let's focus on why your LWCO is flooding your boiler.
>
> Can you post more photos of your near boiler piping? From the posted photo is looks like you header slopes down, loops back, then up hill to the two take offs, and then to the equalizer?
Picture is deceiving. High point is the elbow just above the boiler and low point is the equalizer.

>
> What's your pressure gauge doing while it's running?
I think my pressure gauge is the wrong size. When the system is off it reads 1psi and when it is doing this bouncing between 2 and 3. I need a gauge that only goes 0 to 5 or something.

@ethicalpaul I think I have made this short cycling worse as I have been messing around.

@Gary Smith I am fairly confident that my mains are not counter flow. The high points are at the boiler side and low ends at the drops for condensate returns. I have not removed insulation to check for low spots, but running my long level along the whole run, it is always pitched. I am concerned about the first drain shown in West 1. Piping from boiler pitches to that point before going over the main header. People said the return wouldnt be clogged. I think this proven that when it is off it is cold, but when steam finally makes it that return gets nice and hot.

@gfrbrookline I have my vents listed on my table. I definitely have some 6, C, and D on the east.

bvaughn76

So now my questions.

1) Should my air venting be at the end of my mains or at the end of my dry returns?
2) If at the end of my main, does anyone have good details on how to pipe these? The mains are super close to the joists and I have like no clearance to go up.
3) If my boiler water level was at the marked water line when cold and then dropped after steaming, I have to assume I am not getting condensate back to the boiler. The LWCO kicks in, water flows back, and I start over again. Occasionally the auto fill kicked in. Now my water levels are well above the sight glass. I should be able to produce enough steam and get enough condensate back without doing too low, right?
4) Where do I start first? Should I put No4 air vents in all the radiators and see what happens? Should I address the main venting?
5) If I am putting the vents at the end of the returns near the boiler, isnt that area wet? What vent do I use there, Gorton vents will never see steam there, right?

acwagner

For #3, yes, it should reach a steady state of steam production to water return. The water level shouldn't drop like you are experiencing.

So, either the water is being blown out the boiler into the system, or you have a slanted waterline. I noticed in your photo coming out of your boiler it is reduced to 2".

In the Lost Art, Chapter 4, he talks about having a reduced riser to the header which cause the boiler water to favor the riser side (page 49 on my version).

Does the waterline drop very quickly in the cycle, or is it progressive over the whole cycle?

And, when the water level drops, does it take a while to recover, or when the boiler shuts down it's back to normal in a few minutes?

If it recovers fast, it's probably a slanted water line. If it takes a while for the waterline to recover, it's probably out in the system and taking a while to get back.

Gsmith

If you don't have physical space at the end of the m ains, then put the main vents at the ends of the dry returns, where it looks like they are now. i'd replace those silver vents above the dry returns with Gorton#2's or Big mouth's.

Make sure the steam mains are insulated, and if your main vents are at the ends of the dry returns, insulate the dry returns as well, this helps to prevent the steam from condensing as it hits the cold piping when the boiler starts.

If you are getting low water shutoffs on each boiler start you probably have clogged wet returns. Flushing them out may correct this issue.

I happen to like Ventrite #1 vents for radiators, they are good quality and adjustable. Helps make balancing easier once the main venting is working w

Jamie Hall

Confusions. Are your "dry returns" really dry returns -- that is, fully separated from the steam mains by traps so that they can never see steam -- or are they actually continuations of the steam mains back to the boiler? This is not a trivial question.

If they are actually continuations of the steam mains, then you can put your vents anywhere along them after the last radiator runout that works. Often the easiest place for them is at or near the boiler, but anywhere will work.

If, on the other hand, they really are dry returns (unusual in one pipe systems, but not unheard of), then you either must have crossover traps at the ends of the steam mains themselves or the steam mains have to be vented at the ends. If you are using crossover traps, then the dry return must be vented, but the steam mains don't need to be.

As to what kind of vent. Yes, BigMouth vents do get you more venting for you buck than Gorton #2s. However. Gorton #2s have a float in them, and if there is any possibility of condensate coming anywhere near the vent, I'd use the Gortons.

On the boiler flooding -- or conversely, the water level in the boiler dropping. Again, a critical question: does the water level drop while the boiler is steaming? Or does it seem to happen after the boiler shuts down? I'm going to assume for the moment that it's as the boiler is steaming. You mention a concern about the ends of the returns near the boiler being wet. This leads me to wonder... are those returns near the boiler low enough that water could be backing into them as the pressure in the boiler rises? If so, that's where your water is going. To go back to the commentary on venting, whether those lines are real dry returns or continuations of the steam main, they must be high enough above the water line in the boiler to stay dry -- that is, 28 inches for every pound of steam pressure at the pressuretrol cutoff. If, on the other hand, they were once wet returns but the new boiler has a lower water level -- a common enough error -- then they must be low enough so that they are never allowed to become dry, and that must be true for their full length, not just at the boiler.

If, on the other hand, the water level in the boiler drops and recovers very slowly after the boiler stops firing, and you have wet returns, those returns could be clogged. The water level in the boiler should recover to nearly the starting level within two or three minutes after the burner shuts off. Anything longer suggests clogged wet returns, slowing the condensate. Not that it's impossible, but dry returns and vertical drips almost never clog, and a steam main clogging would be seen in other ways.

bvaughn76

@jaime hall, I do not have steam traps or anything at the end of the mains before the return lines. I may have my terminology wrong. At the end of my mains, there are the drops to the return lines. These are empty when the system is off, hence why I thought they are dry returns. I assume they are full of condensate when the system is running. So, let's clarify which type of return that is. Wet or dry?

So....should I bail on my improperly piped vents at the end of my mains and just put Gorton #2 near the boiler on all my returns? That is a $400 investment for 4 of those guys.

Jamie Hall

How low do those drops go? If they go down to near floor level, and then come back up to the returns, then they are water traps -- and condensate will stay in them between runs. They do a nice job of separating the steam mains from what in that case would be honest to goodness dry returns. What they don't do is allow air to go by -- so you do need the vents at the ends of the steam mains.

Now if they just go lower to another pipe which returns to the boiler, and have no traps on them, then they won't keep steam from going through (or air, for that matter) and you can leave the vents at the ends of the main or have them at the boiler or wherever suits.

You certainly can leave the vents you put in at the ends of the mains -- unless you have one of the more exotic vapour steam systems, which you don't, they are just as well placed there as anywhere.

The terminology can be confusing, I quite agree -- but I think it helps to have it right. A steam main is a pipe carrying steam from the boiler with one or more pipes going to radiators or what have you. A dry return is a pipe returning condensate and often air to the boiler (on any two pipe system, all the air vented from runouts and radiators is carried by a dry return), but is isolated from any steam mains by a trap or water seal so that steam can never get into it (well, hardly ever -- some vapour systems... but let's not worry about that). A wet return is a pipe below the water line of the boiler which carries only condensate.

Steam mains must be vented at their ends, either with vents or with crossover traps to dry returns. Dry returns, if they do carry air (and most do) must be vented, usually at the boiler. Wet returns don't need vents, of course.

Or you can skip all the terminology and just figure out how the water gets back to the boiler and how the air gets out of the system.

The Steam Whisperer

The two most obvious problems I see are that the boiler header is only 2 inch and is too low. Slantfin requires a minimum of 2 1/2 inches and the header centerline to be 18 inches above the boiler. Under sized and incorrectly configured near boiler piping will throw water out into the system, causing the boiler to overfill after the water feeder adds water and the water finally comes back.
Also, the radiator vents are much too large. There are two parts to the air vent balancing equation. First is large vents to vent the mains typically in one to 2 minutes, second is to vent the radiators slowly. With your 30 to 35 EDR radiators I'd only use about 0.03 CFM and the 72 EDR about .06 CFM, especially with tube type radiators. All the radiator vents on the east main are overpowering the main vents and stealing steam from the west main. In addition slow distribution through the mains will slow down the return rate of the water, causing the overfilled problem you are having. We use Ventrite adjustable vents and set the 30 to 35 edr rads at about 2 to 3 and the big radiator about 5 or 6.
Also, uninsulated steam mains will also throw off the balance.

gfrbrookline

Yes, remove the vents at the end of your mains, they are not helping your cause. Wrong spot and pitched the wrong way so they can't drain properly.

You mentioned $400, I only see 2 vents in the picture, are there 2 returns or 4?

Regardless of who's advice you take, Gorton vs. Bigmouth, they are both good vents and I have both on my system, I would put them up on a nipple as high as you can go to protect your new vents. You can use the MoM vents you have to tweak the balancing once you have slowed down your radiator. I also like the ventrites that @The Steam Whisperer (Formerly Boilerpro) recommends and have used them to balance my system. The only reason I switched to Gortons is the the tenants would not stop turning them up which defeated the purpose.

gfrbrookline

Just saw a 3rd vent in the picture, you probably have drip returns that also need to be vented so the 4 makes sense.

Yes it sounds like big money but if your system is anything like mine was before @New England SteamWorks helped me get on the right track with my main venting you will likely make it back in fuel savings over one or two seasons and have a more comfortable living space.

bvaughn76

@gfrbrookline I spoke with New England Steamworks the other week and they commented I am on the right track, but there is a lot thrown at me here and before I drop $800 in venting for the radiators and mains, I am going to have them come out.

I'll post a resolution once I solve this.

bvaughn76

So I can't let this sit. I noticed the radiator at the end of my west main was squirting water out of the air vent. Like streams of water. First I realized the pitch on the radiator was off. So addressed that. Then I was curious....just seems like there is a lot of water in the system. So after morning warmup. I turned off the boiler and let things settle. I broke the union on my condensate line right near the main steam line. There was a descent amount of water that poured out. I was then curious and went over to the boiler. All the air vents on the returns at the boiler are at different heights. I grabbed one I could reach and started wrenching it off. Sure enough when I got it loose water poured out. The water in the sight glass fills the glass. I then opened the pressure relief valve and water drained out of that till I let it go quick. Started taking off other air vents that were lower than the first and more water came out. The water level at the first one went down as I opened lower ones, so clearly water is communicating between the pipes and they are not clogged. So now the water level is at the height of the lowest air vent. I opened the skim port and the water level at the lowest air vent dropped. So I then drained water from the system until the sight glass showed water at the water line.

The first elbow to the east horizontal main is higher than the west. Also the first drain point on the west is potentially below where the water level was.

So I assume cold, my header and the vertical pipes to the east and west along with some of the west main is full of water.

Now i just need to figure out how to keep the LWCO from cutting out the boiler.

bvaughn76

I fired the boiler with all.the vents off and me listening and feeling the pipes.

Produces steam in like 5 minutes. The east pipe got hot like immediately and shortly thereafter the return from the North East was flowing water. I could hear it from the opening in the return. At that point I shut off the boiler.

The first elbow for the east main was too hot to touch. The west main was barely above room temp.

There are no main line vents on the North end of the east main, but clearly that is where the steam is going first. Do I need to trick it to go somewhere else? There are four rads on that section, three being quite large. Downsize the vents there?

KC_Jones

I think you need to abandon the vent situation for the moment and find out where and how all the water is getting into the mains.

IMHO you shouldn't hear water flowing anywhere, there really shouldn't be enough volume on a system like yours to hear that.

@Gordo recently posted this video showing the condensate return opened up and draining. You can see it's a small volume of condensate coming from the system. This is the only water that should be there.

https://www.youtube.com/watch?v=9Ime0nqP548

ethicalpaul

Or here you can see my return. This is just under 200 EDR worth of radiation

https://www.youtube.com/watch?v=97jhq7fSTuU&feature=share

bvaughn76

@KC_Jones, before I started to take things apart to realize that my water level was easily 6.5ft above the floor, yes, I heard lots of water movement. Which makes sense if the water level was that high. Why water kept creeping up is because the boiler would run out of water and the LWCO would kick in and the autofill would add water.

When I skimmed the water out again and got things back to normal, the flow i heard in the return was definitely like a dribble as he was showing it.

What I have been reading here is that if steam starts condensing it creates low pressure which draws steam towards it. So, if the air vents quickly out of one main and the radiators and system starts condensing, pressure will be lower and steam will favor that. True or false?

If true, I am trying to get steam to the end of my mains as fast as possible and as equally as possible. Right? Venting plays a part in that.

I think the water level issue played a roll in why the west was not heating up, at least when the system got to the state where the autofill over filled the system.

Why enough condensate wasnt coming back and making the LWCO kick in, that is a concern.

I feel like I want to do the following.
1) Get the slowest vents I can on the radiators on the North run of the east main.
2) Add risers to the air vents by the boiler so they are as high as possible. Then put new vents on there. Likely cheap high flowing ones from HD until I sort this out then can put on pricey big mouth or Gorton.
3) See if there is more balance and check the time delta between when the returns start getting hot.
4) See if the LWCO issue kicks in still with new vents near the boiler.
5) Fine tune from there.

coelcanth

bvaughn76 said:

the boiler would run out of water and the LWCO would kick in and the autofill would add water.

^^^
getting to the bottom of this issue should probably be Number One on your list.

something is causing your boiler to flood with water.

could be that the LWCO and autofill are working (mostly) as they should, but if so, you need to know why the waterline keeps dropping below the LWCO.

ideally, you would have valves that allow you to bypass the autofill and only add water to the boiler manually. that way you could monitor the waterline without automatic interference. i can't tell by your photos if this is possible..

at least you could get the waterline set at the correct level during the next boiler cooldown, and then wait for the next call for heat to watch exactly what is happening.

acwagner

I agree with @KC_Jones that you should focus on the boiler flooding. The balancing of your mains is a separate issue. Until you fix the boiler flooding your system won't function regardless of how well it is vented.

What's likely happening is the water from your boiler is being blown out into the system.

Check out this great video from @ethicalpaul:

https://forum.heatinghelp.com/discussion/169320/see-wet-steam-in-the-wild

This is likely why your LWCO is triggering. Your near boiler piping could be the culprit.

Have you tried lowering the boiler water level below the recommended level to see if it still runs and triggers the LWCO?

Jamie Hall

Venting oddities won't cause boiler flooding. Boiler will cause all sorts of mischief, and as has been said must be addressed before anything else.

Step 1. With the boiler cool, drain (or fill) to the midpoint of the sight glass and mark that level. Close all possible valves which can allow water into the boiler. Turn off the boiler. Come back in half an hour. Is the water level the same? If so, good. If not, one or more of those valves you closed is leaking past. Fix that.

If you passed Step 1, Step 2: open the valves which isolate the water feeder, keeping everything off. Go away for half an hour. Water level still the same? Good. Water level changed? Not good. Autofeeder is leaking. Fix it.

Step 3. Now look at your autofeeder. If it has an adjustable time delay (some do, some don't) set it as high as it will go. VXTs for instance go up to 10 minutes.

Now run the boiler and see what happens. The water level may drop, but it shouldn't drop enough to drip the water feeder, never mind the LWCO. If it does, you may have a piping problem (such as a return which was wet once upon a time which got dried out by a new boiler with a lower water line). Wait for the boiler to shutdown normally, and see how long it takes for the water level to recover. Shouldn't be more than 5 minutes, but could be that long.

bvaughn76

@Jamie Hall I let the boiler cool all the way. The water level is constantly at the water line marked on the boiler. It has stayed at the level all day. My feed is not leaking.

What has been happening is that after the boiler runs a bit the water level drops. The LWCO and autofill kick in. This cycle continues until the boiler is over full. The system is heating at this point.

This morning after warm up I started looking to see what my water level was because water was literally squirting out of the radiator air vent at the end of my west main. That is when I started dissasembling as described above and saw the water level was well above 6ft.

So, why does the level drop to the point the LWCO and autofill are kicking in?

Jamie Hall

I think that at this point we need photos of all your near boiler piping, as well as a pretty good description of the piping out in the building.

bvaughn76

Near Boiler Piping

bvaughn76

So, I ran the boiler with the vents removed to see what happened again.

When I heard water flowing (trying to get a video to load up hear), at the "T" closest to the autofill, the water level in the sight glass dropped and then the boiler turned off. I assume LWCO kicked in. Heard water flow and then at one point it flowed up out of the "T" where the vent would be.

The boiler fired again and same thing, after I hear condensate flowing down that near return pipe, the boiler cuts out.

It did this two more times, on the forth time, the autofill kicked in. Boiler cycled like this 6 more times. The autofill did not kick in again. At this time the two return pipes from the east were super hot. The west side main pipe was still cold to the touch.

Out of ideas.

Jamie Hall

Got to admit that at the moment I'm out of ideas, too. Though I have to admit that I don't think I've ever seen a header piped quite that way... and I really don't like the reducer on the riser. But that may be -- probably is -- a side issue.

You should not be hearing water running in the returns -- and certainly not coming out of the vent at the top of the returns. Since this is all one pipe steam, those returns aren't separated from the mains by any traps -- I presume -- and are just serving as drips for condensate return. This is also seen by the returns from the good side getting hot -- steam is getting to them. The fact that water rises in the other line, though, indicates that steam is not getting to it -- it is holding at or near atmospheric pressure, rather than seeing boiler pressure. I wonder if what may be happening to the water is that it is backing up those returns and getting into the problem steam main -- that would account for the water loss and the running water sounds when the boiler shuts off.

My only thought at the moment is that somewhere along that problem child main -- probably very close to the boiler since none of the radiators on that side heat -- there is a pretty complete blockage. At the moment, I'm somewhat at a loss -- as I said -- but I might ask, how far along that problem main does heat reach?

A risky -- and possibly dramatic suggestion. Does steam even get into that takeoff? You could (I told you it was risky) crack the union on the takeoff to see.

I'll sleep on it...

Fred

Does the equalizer get steam hot, from the Hartford loop up to the Header?

bvaughn76

@Jamie Hall if it runs long enough, steam has made it to the furthest boiler on the troubled main. We are talking 30min.

@Fred the equalizer is piping hot

I replaced the air vents on the near boiler returns. Also adding risers to get the vents higher than the drips at the end of the mains. Boiler still cylcing....I did not expect that to change by adding the vents compared to open pipe.

Any thoughts about a restriction in the Hartford loop.

Just sitting here listening to my vents on the "good" loop make lots of noise.

This is so frustrating as this system has never been this bad before when I feel like I have been making all the right updates.

gfrbrookline

@bvaughn76 do you have a pipe snake? If so try removing the vents and running it down the wet return to make sure they are not plugged.

gfrbrookline

One other potential issue I see is you don't have a ball valve on your autofeeder that lets you shut it down or portion it down.

Gsmith

I think most likely a plugged wet return. What is keeping the condensed steam from getting back to the boiler, causing low water then over feeding.

ethicalpaul

If it were a clogged wet return, then I feel the main would get hot before the problem manifested. This is because for a problem to appear in the wet return (let's say, water backing up into it) the main would have to have steam in it that would condense.

Without steam condensing in the main, a wet return problem can't really occur. Agree?

Is the main vent on the problem main accessible? Can you monitor it during heat startup to see if it is actually venting?

bvaughn76

@ethicalpaul there is no venting going on in the troubled main, like steam refuses to go that way to push the air out. I've even removed the vents at the end of the troubled (west) main and did not observe venting. It isn't until the system has ran for 45min where the troubled main gets hot. But now with trying to keep the water level low, the boiler short cycling is really bad.

So, the open pipe shown in this picture is where I removed the vent(likely destroyed with past condensate and have been there a while) on the return from the North branch of the East main. This main heats up fast and has condensate returning quickly. The only vent on this branch is at the end of the return and on the radiators.
I feel like what Dan described in the end of this document is why steam favors the east? https://heatinghelp.com/assets/documents/Balancing-Steam-Systems-Using-a-Vent-Capacity-Chart-1.pdf

When I start to hear condensate returning from that North East branch, is when the LWCO cuts out the boiler.

In the pictures below, I observed the water level drop on the sight glass, LWCO kicks, and then condensate flowed over the top of the open pipe. You can see the pipe is wet and shinny from water flowing down it.

So is condensate not able to return to boiler?
1) Returns have a clog in the hartman loop somewhere?
2) Is there a lot of water in the header flowing down the equalizer, stopping the water from entering from the hartman loop?

It seems like when the boiler stops, the water returns fairly quickly.

Someone also asked about the height of the header. It is 19" above the boiler or 28" above the water line.

acwagner

I bet you have sag in the troubled main somewhere that is holding water that is blocking the steam. I had something similar happen on my system. Super slow main that would never get fully hot. Ultimately, I found a sag in the main which was causing the problem.

If you have an open pipe at the end and steam is still not going down the main, then I would check for sags. You'll have to pull off the insulation to do this.

bvaughn76

@acwagner the first elbow on the trouble main isn't even getting hot

acwagner

The sag could be between your boiler and the first radiator on that line. That would prevent any air from escaping the whole main.