Single Pipe Steam - Inconsistent Heating of Radiators, No/Low Pressure, Inconsistent Main Venting

JoeDi

Hi all, I have been working on my house's single pipe steam boiler system and had originally asked some questions regarding noises the boiler was making last year when i understood the system a lot less than I do now. Instead of continuing asking questions completely unrelated to the thread title I decided to make a new thread with a correct title. (here is a link to the old thread: https://forum.heatinghelp.com/discussion/168850/weil-mclain-steam-boiler-clogged-pigtail-kettling#latest)

After doing a lot of maintenance on the system its running much better than it was, multiple shut off valves were repacked at the stem, i replaced almost all of the air vents on the radiators with vari-vents. The only ones I left were the newer groton brand ones, the older flair brand ones and a couple that looked like they were from the 30s were replaced. I tried to be sensible with the vari-vent settings as well. none of them are full open, the upstairs are open about half and the downstairs about 1/8 open.

After removing the asbestos the prev owner left all the basement mains and returns uninsulated, I insulated all the exposed pipes in the basement with 1 in pipe covers. The vertical runs appear to still be fully insulated with asbestos wrap.

I also replaced the pigtail that was partly clogged but not completely clogged. At first since all my radiators were making noise like a tea kettle whistling i thought the pigtail was clogged, and I thought the the psi was getting over 5PSI and the vents were opening up from the pressure being too high. After fixing all the leaks and replacing the leaking air vents I installed a 5PSI gauge to replace the 30psi gauge i had that was never showing a reading. Once or twice I saw on system shut down the gauge read about half a PSI. I never once saw it move after that day. Frustrated by this I returned the gauge to amazon and bought the 3PSI version thinking it might give me a little bit more resolution however I have never seen the 3psi gauge needle move at all since installing it a week ago. I figured maybe I needed to wait till the weather turned cold again but it did and even though the system has been running a lot, i never ever see the needle move and I have never seen the pressuretrol kick in either, ever.

Now I understand that less pressure is better but I am wondering is it normal to get ZERO reading on the 3PSI gauage at all? I figure even if my system is working with mere ounces of pressure a 3psi gauge should still move sometimes, no? (PS I filled the pigtail with water when i replaced it, no one says to do that but they say the water is what protects the gauge, so i did that when i installed it, just to point that out incase it matters).

Now if the system worked properly it wouldnt really be an issue I guess, i would just assume the pressure is too low for the cheap amazon gauge but since steam is getting to the radiators and they are getting fully hot, there is no issue.

HOWEVER, I am getting inconsistent heating results like crazy. One of the things I did when working on the system was to re-install a radiator that was removed from the master bedroom. the master bedroom had originally 2 small radiators on each side of the room, the previous owners removed one of the radiators and had it capped off. this led to the room always being too cold so I cut the old spud out of the old radiator and installed a new shutoff valve and installed it and it was working great. Then a couple days later the new radiator is cold completely so I think its a bad air valve and replace it and then it started working but then did the same thing a couple of days later. when i remove the varivent there are a few drips of water that come out but nothing excessive. When this radiator works it works great and gets really hot btw. I should point out another one of the radiators on the 2nd floor on the 2nd loop of the system also randomly doesnt get hot although replacing the valve with a varivalve seemed to help that one. The other radiator in the master bedroom always gets hot, really hot, every time the system runs, that radiator is also on the 2nd loop. the radiator that i reinstalled I used 2 metal cups to raise the vent side and get the correct pitch on it.

So those are the symptoms..... What I have already done is replace both main vents in the basement. they were groton #1 main vents but they looked very old and one had paint on it. However, the same thing I observed before I replaced the vents is happening after I replaced the vents. Loop #1 gets hot way faster than loop #2, and many times the system will run long enough for loop #1 to get hot and the vent to get fully hot to the touch and close while #2 is not even luke warm yet, and then the system shuts down like this. I assume this is a big reason why I am having issues. Replacing both vents didnt help (although they leak less now when they are hot so that seems like a good thing).

Now my main vents were on like 2 inch nipple sticking out of the top of the drop at the hartford loop at the boiler. Weil mclain says they should be 6 inch nipples and 15 inches back, not directly over the top. So after reading these forums I did what was suggested to others in the past, I bought some 90s and a 10 inch pipe and got the vents 10 inches back and further up. its my understanding this helps prevent issues with condensate getting up into the vent. this did nothing though to help with my problem (although I hope it may prevent issues down the road)

I should mention this important detail now as well...... Originally the 2nd floor bathroom radiator (which is on the problem loop #2) would make a loud air sound from its groton valve when the system would shut off. I was told that loud sucking noise could indicate bad or not enough main venting as the system is having to suck air through that vent. I should mention that noise went away when I replaced the #1 main vent on loop #2, so I believe #2 main vent was in fact clogged with paint or bad or something even if it didnt solve all my issues replacing it. I have heard ONCE air noise coming from the main vents, i believe it was #2 on system shut down once. Other than that never once heard or felt air coming from the vents (only felt a little steam after they are fully hot). One thing I was considering was buying another #1 main vent and puttitg it on an antler manifold on loop #2. However I am not sure if the issue is maybe too much venting on some radiators maybe. Perhapss instead of looking at main venting i need to be trying to fine tune the vari-vents more?



THANKS! Any info clarification needed just ask!

Details of my system in my next post, this one is too long it says!

JoeDi

My system:
Weil Mclain EG-40 boiler, the piping and radiators are circa 1930s and the current boiler I think is from the 90s.

The boiler has 2 main loops, 2 inch pipe. Loop #1 is 2 inch pipe, 21ft long. Since this is a single pipe system it then reduces from 2in to 1 1/4 in for the condensate return, I did not measure the condensate return but I can do that if needed. Loop #1 handles the front of the house (front of the house has a lot more to block the wind than the back does so the back of the house is typically colder but not always as the back of the house gets more sun late in the day. The front of the house faces E-SE. Loop #1 has only 5 radiators on it and has not been modified since installation. It has 1 extra large radiator in the living room, a large tall radiator by the front entrance door and 2 medium size ones in a sun room and 1 medium in a 2nd floor bedroom (this radiator always wants to get HOT on the 2nd floor, even with varivent shut off completely it still gets hot usuaully)

Loop #2 is 2inch pipe, 30ft long. Also did not measure condensate return but I can if needed. This loop covers the back side of the house and does 3 out of the 4 2nd floor radiators. It has 2 medium radiators on the first floor. There is a pipe capped that used to be a tall radiator in the kitchen that was removed by previous owners. it also has 2 small radiators in the master bedroom (one of the radiaotors i recently reinstalled), 1 medium in a 2nd floor bedroom and a tall radiator in the bathroom on the 2nd floor. So 6 radiators on the 2nd loop, originally 7.


I'm sorry for the wall of text but it seems on these forums more details is always better than less so...... Here are pictures:

This shows how the #2 loop vent is not hot while the #1 loop vent is fully hot for a while:



How the main vents were originally installed:



Original gauge and ptrol setup:



My install of the new gauge w/ union (What happens if there is a leak in my piping here? could it cause the no reading on the gauage??):



New vents moved back:




PS. After cleaing the sight glass I noticed that now when the boiler runs there is a little bit of movement but no surging however every time the boiler runs the sight glass turns brown now. I was going to flush out the boiler as it seems loaded with rust gunk but I dont know if its going to be a problem that they have a 1/2 drain cock soldered on to an adapter, while I can replace the drain cock I dont see how I can get a larger drain on there. The other side of the boiler has a plug but its below the water line and the boiler I think is from the late 80s or early 90s so I dont know if that plug can evfer come out.

EBEBRATT-Ed

So your problem is loop 2. I would check the pitch on any radiators that do not heat and check the pitch on #2 main and branch piping start with that.

Its possible that your thermostat is shutting the boiler down before loop 2 gets a chance to heat.

Just for fun crank the thermostat up just for a trial to see if loop 2 ever heats and how much longer do you have to run the boiler for it to heat loop 2. But check all pitch first.

If loop 2 gets hot with an extra 10-15 min it's probably a venting issue.

Keep in mind you don't want the thermostat in the warmest room.

The fact that your not building pressure is probably not a concern. You don't want to build pressure in a house boiler, but you do need enough pressure to deliver the steam.

Check the other items above before worrying about the pressure.

JoeDi

EBEBRATT-Ed said:

So your problem is loop 2. I would check the pitch on any radiators that do not heat and check the pitch on #2 main and branch piping start with that.

Its possible that your thermostat is shutting the boiler down before loop 2 gets a chance to heat.

Just for fun crank the thermostat up just for a trial to see if loop 2 ever heats and how much longer do you have to run the boiler for it to heat loop 2. But check all pitch first.

If loop 2 gets hot with an extra 10-15 min it's probably a venting issue.

Keep in mind you don't want the thermostat in the warmest room.

The fact that your not building pressure is probably not a concern. You don't want to build pressure in a house boiler, but you do need enough pressure to deliver the steam.

Check the other items above before worrying about the pressure.

Sorry to be clear, Loop #2 does get fully hot and work perfect if the system runs long enough or cycles enough.

The issue is parts of the house get massively hot while others are cold, so while the system running longer does usually solve all issues, typically the system doesnt run that long.

I end up with a house that has 2 massively different heating characteristics based on how cold it is outside. If its very cold and everything runs a lot typically everything gets hot. However most days its not that cold in the NYC area so i end up with some really warm rooms and some cold ones.

I should clarify though that randomly that radiator that I replaced that randomly stays ice cold, typically yes it gets hot on days the system runs longer but there have been some cold days where it ran longer where this radiator never got warm as well. This specific radiator is pitched good, I confirmed it with a level when i installed it.

I've only found 1 radiator so far that seems to be "level" or pitched wrong but its on the first floor on loop #1 that doesnt have the issues, loop #1 works great. I have not been able to check the pitch of all the radiators yet though, or the mains.

Fred

A couple notes:
- If you are using Vari-Vents, on the radiators, they vent to aggressively, even at lower settings and I suspect your problem loop is being robbed of steam because the hot loop vents air faster, out of the main vents AND the vari-vents, at the radiators, making that loop the path of least resistance for the steam. Replace those Vari-Vents with Vent-Rites #1 or Hoffman #1A. They are both adjustable and are much more controllable.
- Check your thermostat. Depending on the type, thermostats come from the factory with a default setting for forced air, 5 cycles per hour. You need a setting of 1 or 2 cycles per hour for the boiler to run long enough to heat the entire system.
- Gorton #1 Main vent is a little shy of what you should have on a 20 foot main. I would use a Gorton #2 or a Barnes and Jones Bigmouth. The main vents should be sized for the size of each main. If the other main is substantially longer or shorter than the 21ft main, added venting will help balance the mains, then you can balance the radiator venting with different vents than the Vari-Vents.
- To you question about the gauge not moving, that is not unusual, especially if the boiler is properly sized for the connected radiation or if the boiler cycle is so short that it doesn't have time to build a couple ounces of pressure. With those Vari-vents, they may vent so quickly that the system doesn't see any pressure, especially if the cycles are shout.

ethicalpaul

I was thinking the same as Fred's first paragraph about all the steam going to the one main. And the rest of his response is good stuff too of course!

JoeDi

Fred said:

A couple notes:
- If you are using Vari-Vents, on the radiators, they vent to aggressively, even at lower settings and I suspect your problem loop is being robbed of steam because the hot loop vents air faster, out of the main vents AND the vari-vents, at the radiators, making that loop the path of least resistance for the steam. Replace those Vari-Vents with Vent-Rites #1 or Hoffman #1A. They are both adjustable and are much more controllable.
- Check your thermostat. Depending on the type, thermostats come from the factory with a default setting for forced air, 5 cycles per hour. You need a setting of 1 or 2 cycles per hour for the boiler to run long enough to heat the entire system.
- Gorton #1 Main vent is a little shy of what you should have on a 20 foot main. I would use a Gorton #2 or a Barnes and Jones Bigmouth. The main vents should be sized for the size of each main. If the other main is substantially longer or shorter than the 21ft main, added venting will help balance the mains, then you can balance the radiator venting with different vents than the Vari-Vents.
- To you question about the gauge not moving, that is not unusual, especially if the boiler is properly sized for the connected radiation or if the boiler cycle is so short that it doesn't have time to build a couple ounces of pressure. With those Vari-vents, they may vent so quickly that the system doesn't see any pressure, especially if the cycles are shout.

Fred, thanks so much this makes complete sense and I had a feeling this could be the case.

The main that works well is 21ft, the main that has the issues is 30ft. both have the #1 main vent.

I should mention that the tapping for the main vents is 1/2. In order for me to get the main vents on something larger would require enlarging the old steam pipe to thread in a larger nipple, something I prefer not to mess with.

That being said, since I am limited to 1/2, would going to a groton #2 make sense or would it be choked off too much by the 1/2 tapping?

I already paid $80 for the 2 #1 main vents, I think the #2s are over $100 each, could I do the antler manifold and add a 2nd #1 vent instead?

Since the main that has the issue is 10ft longer than the other one though, should I leave the #1 vent on the short main that works well and upgrade to a #2 (or add another #1) to the longer main that has the issue?

To back up a bit here though, which should I concentrate on first? The radiator vents or the mains? I already spent $25 each on like 8 vari-vents so if I can avoid replacing them that would probably be ideal. Some were purchased from amazon so i can easily return them but most were purchased from the local plumbing supply house that isnt going to take them back is my guess since they are used.

Fred

@JoeDi , If I were you, I'd leave the Gorton #1 on the short main and add a second one on the longer main. Ideally, I'd replace the Gorton #1 on the short main with a Gorton#2 and add a Gorton #2, along with athe Gorton #1 on the longer main. That will give you a spare Gorton #1 that you can save.
- The 1/2" tapping is fine and has more venting capacity then needed for a Gorton #2 or a 1/2" antler with a Gorton #1 and #2 on it.
- Unfortunately, the Vari-Vents (actually called Heat Timer Vari-valves) are problematic and you will never be able to balance your system with those on the radiators. Bite the bullet and replace them. As far as I'm concerned,those Vari-Valves should be taken off of the market. They vent way too fast for radiators. The old adage: Vent mains fast and radiators slowly.

JoeDi

Fred said:

@JoeDi , If I were you, I'd leave the Gorton #1 on the short main and add a second one on the longer main. Ideally, I'd replace the Gorton #1 on the short main with a Gorton#2 and add a Gorton #2, along with athe Gorton #1 on the longer main. That will give you a spare Gorton #1 that you can save.
- The 1/2" tapping is fine and has more venting capacity then needed for a Gorton #2 or a 1/2" antler with a Gorton #1 and #2 on it.
- Unfortunately, the Vari-Vents (actually called Heat Timer Vari-valves) are problematic and you will never be able to balance your system with those on the radiators. Bite the bullet and replace them. As far as I'm concerned,those Vari-Valves should be taken off of the market. They vent way too fast for radiators. The old adage: Vent mains fast and radiators slowly.

Fred, I've read enough of your replies on this forum that if you are telling me to scrap the vari-vents and start over, then I am going to listen to you. I will return as many as the varivents as i can and bite the bullet on the rest.

I am going to order the emerson vent-rite's you recommended, amazon has them for $36.... These are the correct ones? https://www.amazon.com/Emerson-Swan-Angle-Steam-Adjustable/dp/B072R1RR46/ref=sr_1_1?keywords=Vent-Rites+#1&qid=1581373946&sr=8-1


As far as the main vents. I found the big mouth vent for $89, but its 3/4 so I would also need to buy a reducing coupler.

The gortons #2's are more like $125. With that in mind, do you still recommend I go with the groton #2's?

One thing I could do is put my 2 x #1 on the short main and put a big mouth on the #2 longer problem main, but I am not sure how the big mouth compares to the gorton #2.




that reducing coupler wouldnt be a problem right? I can special order it in 1/2 it says but i can get this stuff tomorrow if i use the reducer.

ethicalpaul

If you want to try getting out cheap, pick up a Maid o mist #1 at supplyhouse.com, it’s the same size as a Gorton (not Groton) #1. Use the ad on this site to go there

And try a few MoM radiator vents also from supply house. Get #4 and #5 sizes and put the 4s on your hottest rooms, the 5s on your just right rooms and leave your monster vents on the cold rooms. Then see what happens. The price will seem insane compared to what you’ve seen but these vents work.

Fred

@JoeDi , Here is a link for Vent-Rite Vents at a much lower cost:
https://ordering.fwwebb.com/woitem/496*1
Also, I have BigMouths on my system and I love them although others have recently had issues with them leaking.
The Bigmouth has about three times the venting capacity of the Gorton #2 and, while that's not a problem on your mains, it is a little overkill for a 20ft and 30ft main, and then to add a Gorton #1 on the 30 ft. main to try and vent it faster than the 20 ft main just seems a bit much but I get it from a cost/value perspective. Here is another link to less costly Gorton #2's:
https://www.supplyhouse.com/Gorton-G2-Gorton-No-2-Straight-Air-Eliminator-3524000-p

gfrbrookline

Ditto what @Fred said.

Getting rid of the vari-vents will make a huge difference.

JoeDi

Fred said:

@JoeDi , Here is a link for Vent-Rite Vents at a much lower cost:
https://ordering.fwwebb.com/woitem/496*1
Also, I have BigMouths on my system and I love them although others have recently had issues with them leaking.
The Bigmouth has about three times the venting capacity of the Gorton #2 and, while that's not a problem on your mains, it is a little overkill for a 20ft and 30ft main, and then to add a Gorton #1 on the 30 ft. main to try and vent it faster than the 20 ft main just seems a bit much but I get it from a cost/value perspective. Here is another link to less costly Gorton #2's:
https://www.supplyhouse.com/Gorton-G2-Gorton-No-2-Straight-Air-Eliminator-3524000-p

Ok so I am thinking I will put a Gorton #2 on the larger main instead of the bigmouth (then i dont need to worry about reducing too).

Then I will have a Gorton #2 on the larger main and a #1 on the smaller and a spare #1, I could then add that spare #1 to either main on an antler manifold, I was going t order the extra black pipe parts i need to make the antler manifold just incase when i order from supply house.

ethicalpaul said:

If you want to try getting out cheap, pick up a Maid o mist #1 at supplyhouse.com, it’s the same size as a Gorton (not Groton) #1. Use the ad on this site to go there



And try a few MoM radiator vents also from supply house. Get #4 and #5 sizes and put the 4s on your hottest rooms, the 5s on your just right rooms and leave your monster vents on the cold rooms. Then see what happens. The price will seem insane compared to what you’ve seen but these vents work.

Well I am saving a lot of money doing this all myself and I value comfort more than most so I am willing to spend more to do it right at the same time I dont like throwing money away either.

I am going to order a few of the maid of mists with my Gorton #2 vent from supply house and try to use them to replace the vari-vents in some places, for $7 its worth a shot!

Fred said:

Unfortunately, the Vari-Vents (actually called Heat Timer Vari-valves) are problematic and you will never be able to balance your system with those on the radiators. Bite the bullet and replace them. As far as I'm concerned,those Vari-Valves should be taken off of the market. They vent way too fast for radiators. The old adage: Vent mains fast and radiators slowly.

is there a chart anywhere to compare HT vari-vent's settings with the vent-rite or Gortons? Like Half closed on a HT is like buying an X gorton?

Its funny because the local plumbing supply house basically forced me to buy them, saying they are the best and all their best steam guys use them......... maybe they have the best markup, idk.. lol

Fred said:

- Check your thermostat. Depending on the type, thermostats come from the factory with a default setting for forced air, 5 cycles per hour. You need a setting of 1 or 2 cycles per hour for the boiler to run long enough to heat the entire system.

- To you question about the gauge not moving, that is not unusual, especially if the boiler is properly sized for the connected radiation or if the boiler cycle is so short that it doesn't have time to build a couple ounces of pressure. With those Vari-vents, they may vent so quickly that the system doesn't see any pressure, especially if the cycles are shout.

Regarding the thermostat, I have an Ecobee 3, its set to single stage steam I think but I went into the settings and the only thing I really found was minimum run time for the heat. The default is 5 minutes which obviously wont do much but I assume these thermostats are supposed to learn how long to run the boiler to avoid overshoots. I could increase the minimum run time. One thing i should maybe do is a complete system wipe/reset since the system is so much different now (and will be even more so when I am done fixing it) than when I setup the thermostat originally.

Regarding the gauge not moving..... This is one thing i am not fully understanding yet and just bought the lost art of steam heat revisited so hopefully I will learn in there but I am trying to understand how important it is for the ptrol or vaporstat to turn the boiler on and off. I was watching a video and someone explained that the boiler shutting off at 2psi and back on at .5psi is what makes the vents work properly and fill the entire radiator with steam????? is that true?

I dont want to open a rabbit hole but i was going to ask next if i should be looking into a vaporstat if my system is truely operating on ounces of pressure?

thanks again.

Fred

- @JoeDi , The MOM's are good vents too. I just prefer the dial adjustment rather than changing orifices to balance the system and then losing those orifices, over time, when something changes and you want to readjust.
- I don't know how much adjustment you have on that Thermostat to adjust "Minimum run time" but 5 minutes is definitely for forced air. It often takes longer than that just to heat the mains, with good venting. I would say anything much less than 12 to 15 minutes will do nothing to get steam to most of the radiators, especially on cold starts.
- You really don't need a Vaporstat, although I have one on my boiler. It is just a "toy" for most one pipe systems. Steam Pressure Up to 2PSI is OK. Most of us like to stay at or below 1PSI but that is mostly because we are anal. When you get over 2 PSI, then you start to reach the upper limit that affects how quickly steam moves. The higher the pressure, the slow steam will move.
- Keep in mind the Pressuretrol or the Vaporstat only controls the set point where the Pressuretrol will shut the boiler down when the pressure gets above the Differential, usually set at "1" (the white wheel inside the Pressuretrol). The "Cut-In" setting (scale on front) only makes the circuit so that the boiler can fire again, if the thermostat isn't satisfied and the boiler was shut down because the pressure reached that "Cut-Out" pressure of the .5PSI Cut-In plus the "1" Differential or around 1.5 PSI. The Pressuretrol does not otherwise tell the boiler when to start or stop. Your Thermostat does that.
- Here is a document created by Jerry Gill that shows the venting. You can see the Heat Timer Vari-vents are 4 or 5 times faster than MOM's Vent-Rites or Hoffmans. Just too fast for radiators.
- Also, I suspect your supply house pushed those Vari-vents to move that inventory. No Steam Pro uses them as a normal course of business.
-

gfrbrookline

The ecobee and nest thermostats both have a rather bad reputation with steam heat. They are designed for modern forced air and don't seem to have the capability to program down to 1 or 2 cph. You will be better served with a higher end Honeywell like the VisionPro or Prestige.

JoeDi

Fred said:

-
- I don't know how much adjustment you have on that Thermostat to adjust "Minimum run time" but 5 minutes is definitely for forced air. It often takes longer than that just to heat the mains, with good venting. I would say anything much less than 12 to 15 minutes will do nothing to get steam to most of the radiators, especially on cold starts.

I will try to do some research on the Ecobee I have to make sure there is nothing I am missing.

Fred said:

-
- You really don't need a Vaporstat, although I have one on my boiler. It is just a "toy" for most one pipe systems. Steam Pressure Up to 2PSI is OK. Most of us like to stay at or below 1PSI but that is mostly because we are anal. When you get over 2 PSI, then you start to reach the upper limit that affects how quickly steam moves. The higher the pressure, the slow steam will move.
- Keep in mind the Pressuretrol or the Vaporstat only controls the set point where the Pressuretrol will shut the boiler down when the pressure gets above the Differential, usually set at "1" (the white wheel inside the Pressuretrol). The "Cut-In" setting (scale on front) only makes the circuit so that the boiler can fire again, if the thermostat isn't satisfied and the boiler was shut down because the pressure reached that "Cut-Out" pressure of the .5PSI Cut-In plus the "1" Differential or around 1.5 PSI. The Pressuretrol does not otherwise tell the boiler when to start or stop. Your Thermostat does that.

I really wish I could see what my system is running at, I am curious how are you measuring your steam pressure when using a vaporstat? Do people who operate their boilers with ounces of pressure also stare at a gauge stuck on Zero or do they use something different?

So you are saying the only purpose of the Pressuretrol (my wheel was set at 2, i changed it to 1, not that it matters on my system) is to prevent the system from building pressure if it runs a long time only. So the video I watched on YT where they said that the pressuretrol tripping the boiler on and off helped the vents operate and fill the entire radiator with steam was straight up wrong or perhaps applies in a different kind of system, maybe a 2 pipe system? I wish i could find the video to clarify what they said.

Fred

@JoeDi , If that's what that video said, it is wrong! The Pressuretrol does not help the vents operate or fill the radiators, on either a one pipe or two pipe. I suppose you could stretch that comment to suggest keeping the pressure within a normal operating range (2PSI or less) help prevent the vents from blowing open, under excessive pressure but the Pressuretrol's sole purpose in life is to keep the system pressure within acceptable operating ranges.
As for those of us who use Vaporstats or Pressuretrols and have 0-3 PSI gauges on our system, no we don't sit around watching the gauge (at least most of us don't, LOL). We make sure the Pressuretrol is calibrated correctly, we make sure the Pigtail is not clogged, we make sure the water level in the boiler is at a correct level and we look at the gauge every once and a while to make sure nothing abnormal is happening. If it shows no pressure on the gauge or only an ounce or two, fine. We look for a consistent pressure reading from cycle to cycle, If that happens to be ounces, fine, if it happens to be a pound, fine. It's the consistency that we are looking for.
If for some reason you normally run at a pound of pressure and now you see no pressure from cycle to cycle, that's an indication you need to look for a Main Vent that may not be closing or a hole in the boiler, above the water line and steam going up the chimney or any other reason for the change in what was normal operating pressure.

ethicalpaul

If you want to see low pressures, these gauges are available in lots of low pressure ranges.

https://rover.ebay.com/rover/0/0/0?mpre=https://www.ebay.com/ulk/itm/324015722178

SteamingatMohawk

This discussion is way too long for my feeble mind. Has anyone suggested looking at the Gill/Pajek report? Most of you guys know more about it than I do. When I got into this stuff it was a real eye opener. He talks about 20 and 30 foot mains, which are similar to my converted 2 family near Schenectady, NY. I tried Gorton #2s, but they made no difference. When I finally did the Gill/Pajek calculations, they showed my mains should be #1s, which were there when I bought the house 30 years ago. I saw a comment about overcapacity in venting above somewhere and when you look at the chart in the report, you can see that a fully shut Heat Timer is equal to a #5, so it is good to get something adjustable lower. I use Vent Rites where I need less than a #4, and a Heat Timer in the coldest room, but only there. The rest are orificed MoMs. I thought maybe his main venting was complicated by the two connecting without a water seal/loop to prevent one loop from starving the other, but in a couple of the pictures I think I see that the two mains come close, but both turn down at the tee with the Gorton#1s and go down to the bottom of the wet return, where they meet and go to the drain valve and back up to the Hartford Loop (I assume there is one). Hopefully, I got the terminology correct.

Fred

@SteamingatMohawk , I posted that Gill/Pajek report for this poster, about 5 or 6 posts above.

EBEBRATT-Ed

@JoeDi

The first thing your looking to do withe the thermostat operation and venting is when the boiler fires up and the steam lines are cold you want steam to get to the ends of both steam mains at about the same time. That is usually a venting issue.

Once that is acomplished, you can work on balancing the radiators to heat evenly

BobC

I have the Gill/Pajek chart, these are the vent rates for different air vents. Most systems want fast main venting and relarively low venting rats on the radiators, the idea is to get the mains filled with steam and then let the radiators all come up at about the same time. If the radiators are venting very fast they will tend to hod the steam.

The heatimer varivent
low setting 0.065cfm
mid " 0,340cfm
max " 0.516cfm

Ventrite #1
1 off
2 0.033cfm
3 0.025
4 0.030
5 0.045
6 0.056
7 0,070
8 0.083

Maid O Mist / Gorton
4 0.028
5 0.100
6 0.150
C 0.283
D 0.341

The heatimer is very hard to control at low vent rates which is where a lot of radiators want to be. The Maid O Mist / Gortons give you a low and then an assortment of higher rates. The VentRite is pretty much just for slow vent rates.

For main vents the gorton and maid o mist # 1 is 0.33 CFM
The gorton #2 is 1.1 CFM
The bigMouth is about 2CFM

That EcoBee might be a problem, you might want to buy a cheap thermostat that is rated for steam or gravity hot water to use while you sort things out. Once things are working better you can fight with the EcoBee.

Bob

nicholas bonham-carter

Do you ever see any pressure during the venting phase when steam is starting to rise, and push the air out of the mains? Generally the back pressure should be under two ounces.
The fact that you show no pressure, when steam has displaced the air could indicate a leak in the boiler, so is there excessive white vapor from the chimney? If so, do an overfill test by filling up to the header, and letting the boiler sit for a couple of hours. Any holes in the sections will result in water on the floor.
The other possibility could be an undersized boiler, but that is unlikely, considering the experiences of people posting here.
Since you have access to a FLIR camera, you could follow the steam through the pipes In a video, and maybe see a bottleneck.
Take out the main vents temporarily and fire the boiler to see if both venting points get steam about the same time, but have a helper to cut the power when both locations have steam coming out.
Remember that the aim is to have a lower back pressure of the total of main venting, than the aggregate total of the rad vents, so ensuring the mains are full of steam, before any risers and rads start to fill.
Test your gauge by blowing into it to see if it really works. Quality Wika gauges from gaugestore.com May be a better choice.—NBC

JoeDi

Hi guys here is an update!

I ordered a Gorton #2 from supply house along with some maid mist vents. I already ordered a couple vent-rites to use as well. My plan is to use the HT vari-valves on the rads that need a lot of venting, the maid o mists where I can and the vent-rites where I need to slow it down/adjustable. All this stuff should arrive today.

Yesterday while waiting for this stuff to arrive I attempted to do a full cleaning on the boiler the best I could. I followed some videos from YT and I drained the boiler completely, drained the hartford loop completely, pulled out the burners and cleaned them good along with the pilot/thermocouple assembly. I also removed the sight glass and the valves and cleaned all that and replaced the orings.

The problem is there is really no way to flush the gunk out of the boiler. The only drain is 1/2 drain cock and its plumbed into the boiler with some kind of a reducing tee so I can't increase the size of the drain larger than 1/2 without removing the entire Hartford loop from the looks of it.

The other issue is that the water feeds into the hartford loop so all i can really do is flush out the hartford loop. I also flushed out the bottom sight glass valve quite a bit and some gunk came from there. I assume the water feeds into the hartford loop to prevent thermal shock of filling a hot boiler with cold water, to allow mixing first. So I assume when flushing a boiler a professional would get water into the boiler a different way, I had thought maybe I could remove the ERV and flush it with water from there maybe? what would be the correct way?

The best i could do was fill the boiler multiple times and then drain it multiple times.

the stuff that came out was not black gunk like i have seen in YT videos, just a lot of rust along with some chunks of rust.

After cleaning though the sight glass is moving much better, i am seeing about 1/2 to 1inch of surging up and down in the glass, that is normal amount i assume? The glass turns dark red with rust though and then it settles ice clear after.

So I guess I am wondering is all this rust in my system ok?

THis is a picture of the problem with the drain:






You can see the reducing tee used that screws me, IDK why they wouldnt have used a regular tee and a bushing???? As a novice that seems obvious to me. Also it appears the drain cock has been soldered on? Not sure how much of that is actually brass and painted black

The burners looked good except for so much white gunk from the pilot which i assume is normal. a few clogged orifices on the burner that i had to clear from the white gunk but very little crap came out of the burners when i cleaned them. I think the pilot was turned up way too high, I turned it down as much as I could and then I got paranoid the adjustment screw might fall into the valve so i stopped. (i know that is possible on some gas regulators)

nicholas bonham-carter said:

Do you ever see any pressure during the venting phase when steam is starting to rise, and push the air out of the mains? Generally the back pressure should be under two ounces.

Never, other than when I first installed the 5PSI gauge, one day on shutdown I saw .5PSI. Since then, evfen with the 3PSI gauge it has never moved. I assume the fact I built up .5 PSI rules out a hole in the boiler though?

nicholas bonham-carter said:

Since you have access to a FLIR camera, you could follow the steam through the pipes In a video, and maybe see a bottleneck.

Take out the main vents temporarily and fire the boiler to see if both venting points get steam about the same time, but have a helper to cut the power when both locations have steam coming out.

Remember that the aim is to have a lower back pressure of the total of main venting, than the aggregate total of the rad vents, so ensuring the mains are full of steam, before any risers and rads start to fill.

Test your gauge by blowing into it to see if it really works. Quality Wika gauges from gaugestore.com May be a better choice.—NBC

Actually, maybe you are on to something. I read that the steam mains are typically perfectly clean because they are steam cleaned daily, but the dry returns could get clogged? When I use the thermal camera the steam seems to stop when it gets to the reducer on the end of the main where it goes from 2inch to 1 1/4. On the camera the steam seems to quickly fill the main's but it doesnt seem to go through the entire loop.

OR maybe this indicates what another guy said that i was venting the radiators just too fast now with the HT vari-valves?

what is weird is that on the thermal camera it appears the main gets hot, then the brances to the radiators and the radiators and then LAST the dry return gets hot and then the main vents get hot but this is long after the radiators are getting hot. on the thermal camera it actually looks kind of like the return is getting hot from the boiler direction, not from the incoming steam.....

I want to try the test you mentioned of removing the vents and then seeing how long it takes for steam to come out but can you tell me what to expect? Will it be massive amount of dangerous steam pouring out? How will I know how much longer the steam takes to get to the end of the 2 mains if I shut down when steam hits? Or am i supposed to let steam pour out of one and then wait till it comes out of hte other? the main vents and the shut off switch and the boiler are all in the same area, would it be safe for me to stand there near the open main vents and observe it close? ( i assume since these are condensate returns its not going to be much coming out of the open vents but want to be smart and safe!)

Thanks

mikeg2015

My $0.10

Vent mains faster

Chuck the Varivents. Use Maid o mist or Gorton 4 on smallest radiators and 5 or 6s on largest. Or use Ventrites. They have enough range to cover about a 2.5:1 radiator size ratio from largest to smallest EDR.

Skim boiler

No pressure reading is ok. Mine runs at less than 1oz. Needle never moves on a 20oz gauge.

mikeg2015

When I vented using 6, C and Ds it was erratic and I couldn’t control it. I tripled the main venting and slowed radiators down to the minimum. The slower I vented the more evenly the radiators heated, the more steam I consumed and the lower the pressures were.

It’s counterintuitive. But venting radiators too fast causes steam to race across the radiator and mix with air and heat unevenly using less steam.


You want a wide open path on the mains and radiators vents slow enough that only laterals heat up while the main is Heating. Then all radiators will heat up at nearly the same time. Due to friction in the main and gravity some early radiators will still tend to heat up a little sooner than later ones.

However if designed correctly, the parallel main should start in the N end of the house and travel clockwise and end at the west. The coldest part of the house with the least sun therefore gets those radiators heated first.

dabrakeman

The Ecobees basically give you temperature swing control, not cycles per hour. If you go into your settings -- installation settings -- differential settings you can set this to +/-1F which would probably be a good normal setting to use for steam in a properly sized boiler system. I have a vastly oversized boiler so I am using the +/-0.5F setting to reduce propensity of getting the really long cycles during colder weather that will eventually trip my pressuretrol. You can go online and download all your runtime and temperature data as well which can be interesting if not useful.