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Steam Radiator Shooting water

rtk123 Member Posts: 11
I know it's call spitting, but if it cover my entire floor I call it shooting... Anyway, I've bought a 1930 house and it has a single pipe steam heating. New boiler was installed on 2005 and the pipes are isolated with Fiberglass. All radiators are working properly EXCEPT of the one in the bathroom. It's a six sections radiator. The air vent is adjusted to fully open, I feel cold air coming out of it when the system is starting. The first two sections get evenly heated (bottom to top), the next 3 sections are only heating on the top and bottom parts, the last section gets evenly heated. The air vent closes and does not make noises, but it spits a few drops of water when it closes. After 10 minutes or so it start shooting bursts of water. The 3 sections in the middle are still cold in the middle...

I've tried:

1) Play with the air vent closing.

2) Replaced the air vent.

3) Add tilt to the radiator.

4) Disconnect the radiator and made sure the bottom section is not clogged, as well as the valve.

5) Play with the valve not to be fully open - This makes a lot of noise and did not help.

I'm not sure what to try next... Any thoughts?


  • nicholas bonham-carter
    nicholas bonham-carter Member Posts: 8,566
    shooting water

    i would try a new vent, preferably a hoffman which has a float in it to prevent that sort of thing. however, also check:

    the steam valve must be be fully open-never closed!

    waterline behavior in the sight-glass-should be clean and steady

    boiler steam piping properly done-compare to mfg's installation instructions, on line, and post pictures here.

    any horizontal pipe leading towards that radiator should  be pitched in line with the flow.

    check your pressure [under 1 psi is ideal] and main line [not rad] venting.

    a copy of "the lost art of steam heating" will elaborate on these points-it's at the shop above.--nbc
  • rtk123
    rtk123 Member Posts: 11
    Done most of it...

    I've already replaced the vent. I'm using VariVelve. Both the vent and the valve are fully open. I am not sure about the pitch of the pipes, but this is on the second floor and connected to the main circle pipe in the basement. The pressure reads exactly 1 psi. Water are clean, I've flushed the boiler completely last week.

    The steam pipes from the boiler seems to be correct to me. I have a the pipe running as a rectangular on the basement, and vertical connectors going from it to the first and second floor. The last section of the pipe has a big vent (I think it is called main). Then it drops to the return pipe to the boiler.

    I am going to order the book, but I wanted to see if there is something I did not think of first...

    Also, I am not sure of the photos you asked me to post... Just the connection to the boiler?
  • Big-Al_2
    Big-Al_2 Member Posts: 263
    edited October 2009

    Making sure your boiler is clean and that its piped correctly is a must . . . because those issues can lead to wet steam.   However . . .

    In my experience, VariValve vents are the vents most prone to spitting, even in a properly functioning system.  The configuration of the valves places the outlet barely above the inlet, plus the valve seats at the bottom, rather than the top.  They don't have a "tongue" to deflect condensate away from the vent either.  they also dont "snap"  closed like some other brands.  When steam hits them, they shut gradually.  All of these issues make them prone to spitting out any condensate that forms in them, rather than letting it drain back into the radiator.   Leaving the vent wide open just makes the situation worse, because the increased airflow through the vent tends to propel condensate right through it.  Any condensate that is in the area of the vent seems to get blown right out.  I have a VariValve on my bedroom radiator, because it doesn't snap open and closed and make clinking noises, but I have to keep it less than halfway open or it spits too much.  I still keep a small square of clear Lexan sheet under it to catch the occasional spittle.  Other brands of vents I've tried there don't spit at all. 

    Too fast of venting can also lead to radiators heating unevenly.  Instead of quietly displacing the air, the steam makes a beeline for the vent, and it closes.  After a few minutes the steam rises and the air left at the bottom of the radiator cools off the vent, and it opens again . . . with condensate now streaming past it from the steam condensing above.  If the vent air is moving fast enough, it blows out lots of water.   

    I'd swap the vent with a different brand and see what happens.  People here seems to like Gortons.   I've used Gorton, Maid-O-Mist, Watts, Hoffman, Legend, and VariValves.  The big Gorton Ds, were a bit raucous, but the others were OK. Varivalves are the only ones that have had a spitting issue.
  • Changevents

    i agree with Big Al  , VariValves have a tendency to spit.
  • rtk123
    rtk123 Member Posts: 11
    New air vent

    Today I've changed the air vent to Maid-O-Mist (I could not find any of the other brands at Home Depot). It takes longer for the air-vent to start spitting water, but it does it eventually. Also, there appear to be a lot of noise within the radiator itself... I've ordered 'The lost art of Steam Heating' yesterday and I hope to get it by next week... Still, any comments are welcome...

    Thank you
  • spitting radiator

    Where is the spitting radiator located on you system? Closest to the boiler? Furthest away from the boiler  etc? 

    Is the water line in the sight glass bouncing up and down a lot? Sounds like you're getting wet steam.
  • rtk123
    rtk123 Member Posts: 11
    Not sure

    I'm new to the house, but based on the pipes in the basement, there is a ring on the basement where each pipe connects directly to the main ring. The radiator that spits is the last one on the ring based on what I can see (without opening walls, purely based on layout of the rooms). This is a tiny radiator, 6 thin sections (it also looks a little different then the other, it's thinner and also have 3 pipes going across all the sections). I've attached a picture of that radiator.

    The water in the sight glass are steady, pressure is at 1 PSI and the water line is about 1.5" from the bottom. I've just tried to flash the boiler again, after about 2 cups water started to come clean...
  • rtk123
    rtk123 Member Posts: 11
    Just tried something

    OK, I've disconnected the radiator today and open the valve when the system was running, it seems like the pipe is pushing water!!! I'm probably going to need to call a plumber...
  • not the plumber!

    Not the plumber! Get a REAL steam boiler pro! Sounds to me that your main steam vent are not working or missing. Read the book and you'll learn a lot about your system. (By the way I'm a plumber too )
  • Condensate backing up?

    Not quite sure what to tell you.


    1.The  pipes are sagging causing a "reservoir" of water to build up.

    2.The condensate is backing up through the return. You mentioned that you were operating at 1 PSI.  Any chance the  pressure gauge is bad? When the boiler is turned off does your water line on the sight glass rise excessively?

    3.It might also be possible your mud leg, the wet return is partially blocked and this slows the return of the condensate.

    If the condensate is backing up this should affect your main vents also. Any sign of a problem with them? If not then I would consider  that sagging pipes are most likely culprit.
  • rtk123
    rtk123 Member Posts: 11
    Main Vent

    I've tried to do some more checks in the basement in the last 24 hours:

    1) The Pressure is 1 psi when the system is running and drops to a

    little below 0 when the system is shutdown and cools. I don't think the

    gauge is bad.

    2) The pipes seems to be "tilted" correctly, I've checked all the

    connectors to the ceiling, the distance from the ceiling is constantly

    raising along the pipe in the correct direction (from the boiler to the


    3) The basement is finished and the main vent is in a hard to reach

    area, so I could not exactly check if it is working properly. However,

    it's definitely don't make ANY noise (venting, whistling or anything


    4) It seems like it takes relatively short time for the pipe to get hot

    (not just warm) to get almost to the last pipe going up, but at the

    last section before the return I start hearing water and it takes much

    longer for the pipe to get hot.

    5) The water on the sight glass doubles when the system get cold.

    With that testing, yes, there is definitely water buildup in the main

    pipe. The question is what causes it... I'm still waiting for the book

    I've order, losing hope for it to make it in the mail today...

    rjb suggested it's the main vent, and like I said, I don't hear it working... I'm going to take it off and blow through it to see if it's venting, but I need to get the system cold again... If anyone has other suggestions, please let me know...

    Thank you all for trying to help me out...
  • mchema
    mchema Member Posts: 37
    edited October 2009
    Main Vents

    Currently I'm trying to replace my main vents. I only have two (one on each 20 foot long main). They don't work one bit. I'm not a heating expert but have been dealing with my steam heat for a month now. I have talked with a few great steam people. I'm also waiting for Dan's books to come in the mail.

    I was told if your vents are undersized they won't work, regardless if they are clogged or not. You want to make the vent end low pressured, meaning you want the air in the system to by-pass all the pipes that go up to the rads and expel at in the mains. When the vents are undersized all the air will expel through the rad vents, leaving a loud HIssss. It's the only place the air has to go. To do this you need more vents than you think. When I first started I though I just needed to replace my main vents with just 1 Gorton #2 per line... Boy was I wrong! I need four per main line, a total of eight main vents. I'm waiting to get the rest of the vents to come in on Monday. I have been told it's worth the investment. You rads will heat up more even and quicker. It will also save you your gas bill, the system will be pushing steam faster b/c it won't have to get rid of the air through the rads.

    I forgot to add. I had to replace a rad vent. I did with a varivalve at the suggestion of someone. I regret getting that horrible vent! It is so ungodly loud and spits water everywhere! and it's a more expensive vent... Not worth it! My most quiet vents are Hoffman #40s...

    Good luck. Happy Steam Heating!
  • rtk123
    rtk123 Member Posts: 11
    Replaced main vent

    So I've replaced the main vent (No 1. vent) as it was clogged to almost clogged. I've used Gorton No.1 air vent... Now I hear it heissing a little (not strong, but I know it's venting). The problem persists... Also, the system pressure raised to 5 psi now...
  • nicholas bonham-carter
    nicholas bonham-carter Member Posts: 8,566
    clogged pigtail

    could the pigtail, on which sits the pressuretrol, be clogged, not allowing the true pressure to be "felt"? that high pressure won't be good for the vents!--nbc
  • gerry gill
    gerry gill Member Posts: 3,045
    yup, i'm thinking the pressure

    the boiler is achieving is to much..vaporstat and two stage firing may be the order of the day there..but yes, the pigtail could be plugged too..heck if nobody has maintained it, it probably is plugged..
    Serving Cleveland's eastern suburbs from Cleveland Heights down to Cuyahoga Falls.

  • Excess pressure is causing the problem!!!!!

    Your maximum pressure on your boiler should be under 2 PSI ! !!!

    Preferably it should be low as possible !!      The excess pressure is backing the water`up your return and apparently flooding into the main and into your radiator.

    As for the excess water when the boiler is cold, I'm assuming your have an automatic water` feeder . What is happening is that the excess pressure is forcing down the water level in the boiler and it's backing up the return. When the water reaches "the low water setting the automatic water feed does its thing and adds more water. That's why when the boiler is turned off and the pressure drops, the water levels out and goes higher than normal in the boiler.   At 5 PSI the water will back up I believe close to 12 feet vertical above the boiler waterline!

      If you don't have a good low pressure gauge, get one from the Gauge Store  http://www.gaugestore.com/products.asp?dept=1123

    I would suggest the Wika 0- 3 PSI   Part # 33020. Use some elbows and tees and add it on to your present gauge. You must keep the 0-30 PSI gauge as it  (though useless) is required by code/insurance, Make sure the gauges are protected from live steam by using a pigtail.

    If the pressure can't be adjusted down you either`have, as NBC mentioned, a clogged pigtail or a broken pressuretrol. If you have to replace the Pressuretrol consider changing it to a Vaporstat which are much more accurate at lower pressures.

    On the Main vents i wouldn't even mess around with a Gorton #1. The Gorton # 2 has 3 times the venting capacity and you can't have to much venting capacity on your main vents!

    See just how low you can get your pressure to go and still have the system operate.

    Lowering the pressure saves fuel and also the system runs more efficiently as steam travels faster at lower pressures.

    - Rod
  • rtk123
    rtk123 Member Posts: 11
    edited November 2009
    More info

    I'm still reading the book, but I think I found a few problems (some I've fixed):

    1) The Pressureetrol was set wrong - 2 psi CUT-IN  + 2 psi diff. I've set it now to 0.5 psi CUT-IN and 1 psi diff. This did not help with the water, but the system runs exactly the same, so I guess I'm saving on energy.

    2) I have 2 mains, 1 header, 1 takeoff. It seems like I have a bullhead. It does not look like there is much room to have 2 takeoffs on this size of header...

    3) This one I am not sure off, please help me figure it out... The main drops about 40" down vertically into the return, but It seems like the return is not completely horizontal, it's pitched ~ 1 inch per 2 feet. Mostly over the waterline, but ~ 1 feet on or under the waterline, the it's dropping into the Hartford loop. There are three questions:

    - Should I consider that a dry return or a wet return?!

    - What would be my A size? Is it effectively 0?

    - If I do have A=0, should I lower it by the missing 5-7" to get the wet return back (I think they have made this issue when they replaced the boiler 4 years ago) or should I set a new pipe (bigger) to be a dry return? I would guess it would be easier and cheaper to drop it a bit...

    4) I've run the system, got it to flood the radiator and shut it down. Let it cool down. Remove the radiator and supply valve and lowered a "probe". The pipe is dry! I would guess it is not tilted wrong. If anyone can offer a different though, please do.

    5) Based on the piping (two main, long and short), I think Rob is right and I should replace the main air vent into No. 2 on the long main, but leave the short return as No 1. I figure this would help balance the two mains, or am I wrong?

    Thank you!
  • Jamie Hall
    Jamie Hall Member Posts: 19,966
    Hybrid return

    I'm not really happy with the sound of the sloping return.  Combined with your mention that someone replaced the boiler four years ago... all too often when a boiler is replaced, folks forget to match the water line of the new boiler to the old boiler, and that can be very important.

    What it sounds like to me is that condensate is backing up in that sloping return, and finally getting to the point where it backs into the radiator.  Not sure, from the descriptions, as to why it doesn't just drain back down the steam main to the boiler, but that's possible.  That would give you the rise in water level when the system shuts down, too -- there could well be a good bit of water trapped up there.

    Two things come to mind.  First, that pipe should either be wet or dry, but I would go for wet -- and I would not drop it just a little, but all the way down, with a much longer vertical leg to the steam main (assuming that didn't mess up my basement too badly!).  Second, I would check and double check the pressure.  Keep in mind the relationship that one psi will raise the water level about 30 inches, give or take.  If you are running at, say, 1.5 psi (too high, in my humble opinion, but about as low as a pressuretrol will go reliably) that means that when the boiler is running, any pipe less than about 45 inches above the water line is going to have, or try to have, water in it, unless it has steam pressure on top of it -- and returns should not have pressure in them.  That's surprisingly high! 

    Sometimes it can take a good bit of head scratching to figure out what's happening...
    Br. Jamie, osb
    Building superintendent/caretaker, 7200 sq. ft. historic house museum with dependencies in New England
  • rtk123
    rtk123 Member Posts: 11
    edited November 2009
    What I was thinking

    First of all, just as a reminder, I'm a newbie to all this, so it's just a calculated guess:

    1) The air vent is not letting enough air out, so pressure is been built on the end of the main.

    2) Water are backing up on the return AND on the main due to the pressure on the end of the main.

    3) As pressure builds on both ends of the main the backed up water within the main are been pressured into the second floor radiator...

    I am not sure if this is something you guys can confirm or not... The main question is why would the it continue to through water after a long while assuming once the air finally gets out of the main there should be enough water pressing down on the return... Also, the main is about 45" from the water line, and the water coming out of the radiator on the second floor... Also, it does not throw any water on the radiators on the first floor even when the supply valve for that radiator on the second floor is shutdown... I mean the mains are not shifted that much, I would have thought water would back up on those too....
  • Pressure / Return

    Hi- I think we are "chasing our tails" a bit here and in these situations I've always found it beneficial to go back to the "start" and go over things again.  First of all could you provide us with some pictures of your boiler and the piping around it. Also let us know the  make and model number of the boiler.  Do you have the location of the Non Operating (cold) Water Line marked on the sight glass?

    I suspect that you have a problem with either too much pressure and/or a partially blocked return.  Let's take the pressure situation first.  Have you removed and inspected the pigtail?  If it is clogged or restricted in any way, this can cause a problem. From the factory they usually put "cheapie" steel pigtails on a boiler and I've found simpler to just replace them with a new bronze /red brass pigtail than going to the trouble of cleaning the "crud " out of the old ones. Also the bronze /red brass pigtails don't corrode, so you're less likely to have a problem with them in the future. If you don't have a good local source, you can get brass /bronze  pigtails on the internet from either Pex Supply or McMaster Carr .

    Gauge- While your pressure gauge apparently "works" , I would definitely get a 0 -3 PSI gauge mentioned earlier in this thread from the Gauge Store. It will come in very handy and it is also a good check on the accuracy of the original gauge. While the 0-30 PSI gauge is practically useless at low pressure, you must keep the 0-30 PSI gauge attached as it is required by code /insurance. I've attached a drawing I did for someone else that might be of use to you. Since your system was operating at a over 3 PSI you must be "suspicious" of all vents at this point as they may have suffered damage.

    As to your questions.

    1) The air vent is not letting enough air out, so pressure is been built on the end of the main.  Ans. - the air vent isn't causing this problem!! Any build up of pressure would more or less evenly occur over the whole system (no pressure buildup at a specific location)  and the pressuretrol should shut off the boiler when it gets to the set pressure. Vents just let the air out so the steam can get in.

    2) Water are backing up on the return AND on the main due to the pressure on the end of the main.
      Ans. - As mentioned above pressure is virtually the same over the whole system when it is closed. (We're not taking into consideration the vacuum caused by condensing here.)

    3) As pressure builds on both ends of the main the backed up water

    within the main are been pressured into the second floor radiator...
    There isn't supposed to be water backing up into the main. "Backing up" is caused by too much pressure in the system or the return is blocked / partially blocked which prevents the water returning to the boiler. You mentioned that the boiler waterline is higher at the end of a cycle than when the boiler started the cycle. What is happening is that the boiler is making steam and the first possibility is that excess pressure is pushing the boiler water level down and up the return. If it pushes the level down to the point where the  automatic cutoff turns on and adds water, the cooler water  will inhibit steam production slightly temporarily and the pressure will drop but when the boiler regains the steam pressure again it will push the water level in the return higher and this cycle will continue until the water has flooded the main.  In the second possibility, the same thing will happen if the return is partially blocked. The boiler makes steam and the water level drops. Since condensate isn't returning as it should to the boiler because of the blocked return, the automatic water` feeder does its job and adds more water, Depending where the block in the return is located the water backs up (like a plugged toilet ) and floods the main.

    You might want to time the interval between when the boiler is turned off and the water completely returns to the boiler.( The water level stops rising)  If the water's return is fairly quick this tends to make one think that it is more of a pressure problem than a clogged return. If the return is slower that might indicate the problem is the return.

    I would imagine that the lateral going to the spitting radiator is quite close to the end of the main and so the steam traveling to this radiator is picking up excess water from the flooded main. As Jamie mentioned your return setup seems a bit "different"  and it kind of hard to visualize mentally. Could you possibly provide a picture or a drawing? Maybe a drawing something like the drawing on Page 81 of "The Lost Art..." with the "A" dimension and the dimension to the end of the main, and the dimension from the water`line to the wet return.

    You're progressing and will soon have it figured out.

    - Rod
  • rtk123
    rtk123 Member Posts: 11
    edited November 2009

    I've attached images of the boiler and plumbing around it... Sorry I could not include the entire Hartford loop, it's partly hidden by the water heater.

    The boiler is a WEIL-McLAIN, model EG-45.

    I'm going to printout the schematics you've attached to your post and build it, hopefully I could find someone helpful in Home Depot to help me find all the parts...

    I've took out the Pressuretrol and blow through the pigtail, it was clear. I've set next to the boiler through an entire cycle and here are the finding:

    1) System starts up and water level raise by 0.5".

    2) As steam releases the water level drops, about 1" below starting point.

    3) The return get warm after the short main is completely full and the connected radiator start venting air (first 1-2 section get hot).

    4) The long main is moving fast until reaching the first radiator and then starts to slow down a bit (I have 4 radiators connected to it in a 10 feet stretch). After the 4th radiator it goes extremely slow to go to the end of the main and the last radiator.

    5) Water level stays the same, no jumping.

    6) Pressure gauge still not moving (below 0).

    7) You can start hearing water approaching the end of the long main. No water hammer in the main.

    8) I can hear the last radiator air-vent hissing from the basement (it's on the second floor). I can hear water hammers coming from there. The pipe is going through the kitchen, but water hammer is not in the kitchen walls.

    9) Pressure gauge still not moving (below 0).

    10) The radiator on the second floor gets hot while getting hammered. It is getting hot on both the top and bottom, though top get warm faster. Air vent is still hissing.

    11) After a while it starts spitting water and cover the floor.

    The thing is, I know the pigtail is clear now (I've checked, right!?) and the pressure on the gauge is still 0 throughout the cycle... Hopefully I get a better reading with the second gauge installed...
  • Charlie from wmass
    Charlie from wmass Member Posts: 4,237
    A picture says a thousand words for sure

    The last photo shows an undersized riser and it it copper. Simple thing to say copper bad steel good. The bull tee is bad and the riser is too small and of copper which makes it work like it is even smaller. I am sure others will be able to add even more. I vote for a repipe.
    Cost is what you spend , value is what you get.

    cell # 413-841-6726
  • rtk123
    rtk123 Member Posts: 11

    Actually the spec calls for 2" header and 2" raiser... Based on the connections (the copper seems to be quite thin) it seems like those specific pipes are sized correctly.. I also have 24" from the waterline to the header...

    Yea, the bullhead might be a problem, the question is can that be causing the water on the second floor? I know I need to look at the system as a whole, but I want to make the change that is most like solve the water problem on the second floor... I can deal with the rest either on the same shoot or later, depends on the cost associated with those changes... Based on what I read on the book the bullhead will just cause "waves", wouldn't it?
  • Boiler

    **!&^%#$$** !!   I just finished a long reply and it apparently just disappeared into cyber space! Okay we try again!

    The info and pictures are a big help.  As noted, there are some irregularities with the piping which should be addressed somewhere down the line.

    The thing that bother me is the "no movement" on the pressure gauge during operation.

    What causes the boiler to shut off at the end of a cycle? Normally it would be the pressuretrol or the thermostat. However in a low water situation it could also be the LWCO.  I think I'd address the pressure issue first. You'll need to put on the 0-3 PSI gauge. It's a big benefit as even very slight pressure will move the gauge so you know that it's working.  When we 're sure the gauge is operating okay, we can check the pressuretrol settings and adjust if necessary. The system should be operating at a max of 2 PSI and hopefully even less that that. (More pressure = more fuel.)

    You mentioned having the specs. so I'm assuming you have the boiler's manual. if not here is the link where you can download a copy.


    If you haven't done so already I'd mark the Waterline (cold boiler) on the boiler cabinet  behind the sight glass and also mark the waterline (cold boiler) on the sight glass. (Marking the waterline on the cabinet makes it easy to re establish the mark  on the sight glass if the mark there gets wiped off.)  According to Page 14 in the manual, Fig 18, the waterline (cold boiler is 23 13/16 inches perpendicular to the base of the boiler.

    The base of the header should be 24 inches MINIMUM above the Waterline (cold boiler)  If when the Starting waterline is above the Waterline (cold boiler) mark we are below the Minimum measurement and will quite probably have a problem wih "wet steam".

    If you drain of some water and lower the waterlevel to the marked Water Level (cold boiler) what happens during the operation?  The Operating water line should drop to close to the bottom of the sight glass but still be visible. if it drops below this the low water cut off should activate and have the automatic water feeder add water. Observe if this is happening.  When the burner shuts off and the boiler cools the waterline (because of the added water) should rise above the  Water Level (cold boiler)

    In subsequent operation does the boiler maintain this higher waterline (when the boiler has cooled)  or does the waterline go higher and higher?

    It seems from the previous posts that your boiler is running out of water. We speculated high pressure and clogged return. However if you look at the article "Condensate Return" on Page 16 of the manual, running out of water`may not be that unusual.  (I don't think they would have mentioned it if it wasn't happening fairly frequently) Boiler manufacturers have the problem of balancing having enough water for a steam system yet not  having an excess amount as heating excess water is uneconomical. It maybe you need a reservoir tank though let's get the pressure situation under control first and see what that does.

    - Rod
  • emm
    emm Member Posts: 2
    Test your radiator for sagging pipes to the riser

    Rod suggested that the pipes might be sagging causing a "reservoir" of water to build up.

    Water may be collecting between the riser and the radiator.

    A good way to test this therory would be to raise both ends of the radiator. Still be sure and keep the radiator pitched. Use a lever to elevate the radiator while you slide wood blocks underneath.
  • emm
    emm Member Posts: 2
    Disregard Last Post

    I just noticed the image of the radiator, and I see you already have blocks under all four legs.
This discussion has been closed.