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Single pipe steam boiler - Need assistance with multiple issues

Hi friends,

I have an Independence boiler Model Number IN4N Dated 11/97
I have a number of issues I will be addressing and I greatly appreciate any help with one or all of these issues.

In the first year of home ownership (approx 3 years ago), I had the boiler serviced by a licensed plumber. They drained/flushed the boiler and changed out the faulty pressure gauge, drain and sight glass.

Unfortunately, they were unable to help with the surging I can see in in the sight glass.
There is dirty/rusty water in the boiler, which I drain off about once/week. Every plumber I have had in the house has advised against introducing a cleaner into the boiler.

A few weeks ago, when I turned the boiler on for the first time this season to test the system, I noticed water pouring out of one of the radiator valves, I immediately ended the test and discovered that there was a crack on the valve where the threading begins. After changing out the valve myself, I no longer have that problem, but the water pouring out became an issue of concern. In my opinion, the system had not been on long enough to produce that level of water through condensation. This began hours worth of research where I discovered the term wet steam. I believe I have wet steam because of the volume of water I saw coming out of the valve, coupled with the fact that there is surging, short cycling and water getting inside the radiator vent valves causing them to malfunction and not vent the cold air out of them to allow the hot air in.

-Wet steam
How to deal with/eliminate wet steam issue and why is it happening?

-Short cycling
Why is this happening and how to remedy?

-Water in vent valves
Radiators stay cold if the vent valves have filled with water. How to fix this issue?
This is a constant problem that causes many issues.

Why is the boiler surging and how to fix the problem?
Is some surging acceptable?
Considering that there is rust throughout the entire system, how can I eliminate the rust that causes the dirty water and surging?

-Sight glass
What is the proper water level for my boiler? The boiler didn't have a mark for water level.
I looked this up online and according to the manufacturer it is 28.63". This is 3/4 of the way up the sight glass. This is very high in the boiler. Does this seem correct?
-Automatic water feeder
The auto feeder only adds water to just above the level of the low water cut-off. This is inches below the 28.63" manufacturers recommendation for operating water level.
Is the auto water feeder supposed to introduce just enough water to satisfy the low water cut-off or is it supposed to fill to proper operating height in the sight glass/boiler?

-Cut in setting. It is set to .1 KG/2PSI
Is it set correctly? I have never adjusted this setting.

I have done extensive research on how to vent my mains quickly with the proper calculations, but as an amateur, I am unsure if I am doing it correctly and exactly what formulas I should be using.
My mains are 2.5" black pipe and there are 2 runs with some common piping coming out of the boiler.
The long run measures 48.5' in total (Including common piping)
The short run measures 37.5' in total (Including common piping)

I have 2 old main vents at the end of the runs. One seems to be a Hoffman 4A on the long run and the short run has a larger vent that seems to be antiquated. I am only able to remove the vent from the longer run and in fact I ran a test to see how quickly the mains heat up with that vent removed. It took approximately 17.5 minutes to heat the long main.
In a separate test, the short main was hot in about 15.5 minutes.
-Main vents
Which brand and model vents should I install on the long main and the short main?
Also, any advice on how I can successfully unscrew the stuck vent on the short main without breaking and or damaging the threads?
I understand that the main vent should be installed 6-12" above the main. Based on my pictures, please advise on best height and way to achieve this considering the joists are obstructing to some degree.

I have noticed that my largest radiators won't get completely hot on the bottom half, even if the boiler has been on for hours.
Does this mean that there is sludge inside?
What else is causing this issue?
What can I do to remedy this? How do I get this stuff out?

How long should a system like mine take for the radiators to be fully hot and how long should the system operate. I understand that this is very subjective, but my system can easily run for 1.5 to 3+ hours and not all the radiators are completely hot. This seems to be a problem. Why is it taking so long to heat?

I have gone down the rabbit hole for hours on this site and many of dan Holohan's (and others) articles and videos. Even though I am far more knowledgeable now than I was before, I am still an amateur, who is not incredibly handy. That being said, I can follow instructions, and appreciate any and all help/references you can provide.

Thank you guys so much for all the shared knowledge.



  • Jamie Hall
    Jamie Hall Member Posts: 23,650
    Mercy. Well, let's see here.

    Surging. A small amount of surging -- an inch or two on the sight glass -- is acceptable. Much more than that really isn't. It may be that there is still enough oil in the system to be a problem, which can only be cured with skimming the boiler. Which would not be hard, if the skim port on the boiler were accessible, which it doesn't appear to be. I think we can come back to that...

    There is no need at all to drain and flush the boiler unless it is really badly sludged up. While there would be no great harm to draining it completely and refilling it, it's not likely to help much, and regular draining isn't either needed or recommended.

    The tape on your boiler looks as though it is set about right for the normal water level with the boiler off. You may need to add water manually from time to time to keep it there -- but be aware that if there are no leaks or other problems, anything more than a gallon or so a week (some would say per month!) is too much, and you need to figure out where the water is going.

    Your low water cut off and automatic level control are set where they are to protect the boiler, and add just enough water to allow the boiler to keep operating safely. What is the make and model of your automatic water feeder? It may be possible to adjust it to add more water at a time.

    The cute little silver bullet shaped vent in your photo is a radiator vent, not a main vent, and regardless of whether it is working or not it is much too small. I'd get rid of it and put a Gorton #2 on there instead. Due to the wall being right there, you may need to get clever with a union and a close nipple to get it on there.

    The other, bigger vent may or may not be working. It is big enough, but it is also old and may have failed. Try another Gorton #2 instead. With the joist right there, you may have to get clever with a union as well as a close nipple to get it on there.

    And... what is the copper pipe that comes into the side of the pipe for that vent?

    12 inches above the mains would be nice for the vents. It's not absolutely necessary,

    I notice that there doesn't appear to be any insulation on what I can see of the mains. This is a major problem, and certainly contributes to both the wet steam situation and to the time it takes for the steam to reach the ends of the mains. That is easy to fix.

    Assuming that you have the usual pressuretrol with only one scale, the cutin should be set to 0.7 psi.

    The radiators only getting hot on the top half to two thirds is more or less normal if the run cycles are short. They don't accumulate much if any sludge, so there's no point in even thinking about trying to clean them.

    The overall wet steam problem... some or a lot of it, depending on how the steam mains are sloped, may be related to the lack of insulation. Some of it may be the running pressure, depending on whether the mains drip to wet returns or not. if they do not drip to wet returns, however, a good bit of it may be due to the near boiler piping arrangement, which will be hard to do anything about.

    That's all for right now... from me, anyway.

    Br. Jamie, osb
    Building superintendent/caretaker, 7200 sq. ft. historic house museum with dependencies in New England
  • clammy
    clammy Member Posts: 3,114
    For starter you near boiler piping is horrid . Both of the riser should have been used in piping the header . From your pics none of your pipes are insulated which always is not a good thing . It looks from your pics that there# a second dry return tiring above a existing dry return not right . That separate dry return should tie in to the wet return separately and have its own vent . As for really cleaning the boiler The drain valve should be removed and or the plug in the return tee on the boiler inlet as per the instruction manual and the boiler wanded out till all mud and rust are remove and water is clear and then skimmed . I would image from the pics 99% of your issues are near boiler piping related aside from needing new main vents and most likely radiator vents . As for insulating your system piping use only 1 inch wall thickness fiberglass pipe insulation ,this will help put the heat where it’s needed in your radiators not your basement and stop steam from condensing in your mains and grooving the bottoms of your pipes which over time will cause leaks at the threads . Also for starters have you done a edr on your radiators to see If you boiler is sized correctly ? Where u located and have you tried to contact anyone listed on this website ,some times you have to have some one who knows steam not just any plumber and also some one who is not afraid to tell the truth weather or not they get the repair or repipe ,replacement job or not ,it’s known as being a professional and tellin* it like it is . It’s not that hard all the tools to do it right the first time are right in the instructions manual w piping diagrams not that hard what’s hard is to get guys to follow them and improve upon them, truthfully not difficult at all . As for main vents try gorton no 1 Peace and good luck clammy
    R.A. Calmbacher L.L.C. HVAC
    NJ Master HVAC Lic.
    Mahwah, NJ
    Specializing in steam and hydronic heating
  • MJBaldwin
    MJBaldwin Member Posts: 5
    Thank you Jamie for the quick and in depth response.
    The surging is minor, under an inch.
    After a heat cycle, if I drain a couple seconds of water, it will always be brown and then run mostly clear.
    Is it beneficial at all to drain off any water to get this out? If yes, how often should I do this?
    I always refill water if I do drain any off.
    I put the tape on the boiler with the 28.63 on it. That's what the boiler manual states is the correct level.
    The water level in the sight glass remains consistent after heating cycle. I'm not seeing much if any loss of water.
    VXT-24 Programmable Water Feeder
    The copper pipe is feeding one of those segmented short wall radiators (sorry, I don't know what they're called) in my kitchen
    My next project will be to source and install insulation on the mains.
    The pressuretrol only has one scale and the lowest setting is 0.5 PSI
    I'm unsure what is considered a short heating cycle vs a long cycle, but I'm guessing I have long heating cycles where the larger radiators remain cold on the bottom 50%.
    I believe the mains do drip to wet returns. It sounds like what I have, but I've never heard of that before. I'll attach a picture.

  • MJBaldwin
    MJBaldwin Member Posts: 5
    Thank you Clammy for the insight and advice.
    I'm hoping that once I insulate and change out the main vents, that will solve some of my problems and then I can replace radiator vents so I don't ruin any more of them with water.
    I have not done an EDR on my radiators to see If the boiler is sized correctly. I'll research how to do that.
    I live in Nassau County, NY.
    I did look up the recommended plumbers in my area and plan on contacting them once I resolve some of the easier issues.
    Can you advise on questions to ask them and how many hours they would need to spend in my home?
    Can you tell me if I am looking at spending hundreds or thousands to address my issues?
    I understand this is subjective. Just want to make sure I hire the right people and avoid the issues I've had with previous plumbers. Like you said, I just want honesty and someone with real steam boiler expertise. I have no problem paying an expert who will actually fix my problems.
  • cross_skier
    cross_skier Member Posts: 201
    Main vents are super important and will have an immediate impact.  You may be so amazed that you will add a bunch of them.  Steam simply can't go through main plugged with air.  I purchased a property that had main vents like yours and the previous owner was paying over $3k/year for heat in a 2700 sq ft house.  Vent the hell out of the mains and risers.  The radiators should be vented slowly.

    Insulating the mains will allow radiators at the ends of the mains to heat.
  • Jamie Hall
    Jamie Hall Member Posts: 23,650
    I'd run that pressure control down to about 0.7 psi -- it's the adjusting screw on the top.

    That amount of surging isn't an issue, and I'd not bother to drain any water off at all. Looks you're pretty good on that.

    Bigger main vents and insulation are going to make a noticeable difference -- well worth it.
    Br. Jamie, osb
    Building superintendent/caretaker, 7200 sq. ft. historic house museum with dependencies in New England
  • mattmia2
    mattmia2 Member Posts: 9,959
    Where are the vents located on the radiators? They should be maybe 1/3 to 1/2 way down on the side or so, if they are too high the steam will move across the top of the radiator and close the vent while trapping air in the bottom of the radiator. This may not be a problem if you get adequate heat, but the radiator won't produce as much heat as it could, which isn't a problem as long as it is enough heat.
  • mattmia2
    mattmia2 Member Posts: 9,959
    The near boiler piping certainly could be better but it doesn't look awful. It very possibly could need skimming since it doesn't seem like it even has the port to do that installed. The manual says the second riser is optional in that size, the combination of oil that was never removed from the boiler and the marginal header arrangement may be enough to throw significant water up in to the system.

    I'm sure the lack of functioning main vents isn't helping but I'm not exactly sure how that ends up putting water in the mains.

    Turning the pressure to the bottom of the scale with the screw on top of the pressuretrol and turning the differential dial inside all the way down't won't hurt either.
  • MJBaldwin
    MJBaldwin Member Posts: 5
    Thank you for the replies, Matt. I have a few different styles of radiators. Most have the vent in the middle. The others are just above the middle.
    Just to be clear, I'm not getting water in the main vents. I am finding water in the radiator vents when I have to remove them because they are not allowing heat into the radiator.
    I just lowered the cut-in and turned the differential dial to 1.
    JUGHNE Member Posts: 11,108
    edited December 2021
    I believe the skim port tapping is on the right side of the boiler, lined up with the outlet riser pipe. The lower left corner of that label might be just touching it.

    There is a knock out in the blue cover that can be removed by hammer and screwdriver to knock one side of the circle in and then the other. Twist to completely remove.
    Behind that is a pipe plug, maybe 1". They can be a bear to remove.
    A 8 point socket and impact driver might remove it. Add a pipe nipple, 90, nipple, ball valve and nipple/ cap.

    This will let you slowly float the oils and other floaters off the top of the water.
  • MJBaldwin
    MJBaldwin Member Posts: 5
    Thank you all again for taking the time to contribute and educate me further.

    I installed a new Gorton #2 at the end of the long main.
    Can someone please tell me if it looks good or not?

    How can I pipe the main vent back at least 15" from the end of the main like Dan suggests, when the end of the main is at the back wall of the house?
    I raised it up over a foot, but what should I be worried about since I didn't set it back 15+"?
    I don't want to ruin a new & expensive Gorton #2

    It appears that both mains are in a tee at the very end of the main. Is this true based on my pictures?
    I posted new links, but it's also in the most recent group of pics I posted.
    What can I do to fix this?
    I'm not noticing water hammer.

    The long main (uninsulated for now) with the Gorton #2, vented in just under 20 minutes from a cold fire.
    It took just under 10 minutes for the boiler to heat the first pipe coming out of the boiler.
    Does this mean it took 10 minutes to vent my long main?
    Is this reasonable? Besides insulating, how do I know what size vent to add with the Gorton #2 to speed this up?
    What is considered the end of the main? The last radiator being fed from the long main is 10 feet from the end of the long main. Should I calculate how long it takes for that branch to get hot or the end of the main?

    I need to purchase another main vent but wanted some input regarding the Gorton #2 vs Barnes & Jones Big Mouth. It's not much more expensive and maybe it will vent my long main quicker. Anyone know the B&J venting capacity? I don't see it in the Using a Venting Capacity Chart manual.
    From what I've read on this site B&J vents much quicker, but I have no idea.

    Can I use the manual on the US Boiler site under the independence link for my 1997 IN4N boiler. Are all IN4 models the same regardless of year?
    Does anyone have a link for an easier to read near boiler piping diagram for a steam dummy. I'm having trouble following the manual online.
  • neilc
    neilc Member Posts: 2,716
    MJBaldwin said:

    Thank you all again for taking the time to contribute and educate me further.

    I installed a new Gorton #2 at the end of the long main.
    Can someone please tell me if it looks good or not?

    How can I pipe the main vent back at least 15" from the end of the main like Dan suggests, when the end of the main is at the back wall of the house?
    I raised it up over a foot, but what should I be worried about since I didn't set it back 15+"?
    I don't want to ruin a new & expensive Gorton #2

    that 15 inches is more to do with where the vent pipe comes off the main,
    it is preferable to be back from the 90 the 15 inches so condesate carries past, and doesn't try to jamb itself up the vent riser,

    what you have there is good, as good as it gets without breaking into your main, 15 inches back,
    that riser height, and those 2 90s are your friend there, and should be good protection for the new vent,
    now do the same at the other,

    I didn't read all the way back, but,
    what's your boiler pressure? low is your friend,
    0.5 cut in, and ~1.5 cut out,
    this too protects your vent(s)
    known to beat dead horses