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Vents getting \"waterlogged\"

LanceT Member Posts: 19
I already checked the pitch with a level and they're all pitched slightly towards the pipe. Should I try to pitch them more towards the pipe?

How can I tell the difference between "condensate not draining from the radiators" and "wet steam being pushed up from the boiler"?


  • Elias
    Elias Member Posts: 22
    vents getting \"waterlogged\"

    Some of the vents on my radiators, a one-pipe steam system, are filling up with water and then shutting, giving me some cold radiators. I've got a vaporstat, and a gauge that reads in ounces. I'm cutting out at 12 oz, back in at 4 oz. The radiators are not backpitched. A dimension good, B dimension good. Think boiler needs to be skimmed, I cleaned it with tsp, not steaming it, as per weil mclain recommendation (they have a bulletin with a cleaning procedure, that doesn't mention skimming), but didn't skim. I know, duh. while I don't think this is necessarily the root of the problem, I'm thinking of replacing all of the Maid-O-Mist vents with Hoffman. They seem to be crappier, and when they are getting watery, it doesn't seem that they can drain (I know, get to the root of the wet steam problem). They also don't seem to close up fully sometimes.

    I'm going to do some cleaning, boil some of the water in a pot and also blow down the gauge glass to see if water surges through the top fitting, etc.

    BUT, does anyone have an opinion on the "maid-O-mist" vents as opposed to the Hoffman?
  • vent recomendations

    do a search here for maid of the mist, and every post about them will come up. the button for that is in the orange area.
    i have only ever used hoffman, but some here like gorton very much
    how is your near boiler piping.that could be a source of wet steam--nbc
  • Elias
    Elias Member Posts: 22
    Thanks NBC!

    Excellent. I hadn't noticed the separate search feature. Things seem to point to something that I knew in the back of my mind all along. That Maid-O-Mist are "the cheap thing that looks very similar to the good thing (Gorton) that costs more". Usually those things suck, no matter what field we are talking about.
  • Elias
    Elias Member Posts: 22
    near boiler piping

    The near boiler piping is set up well, everything was done with careful attention, using "the Lost Art" as a guide. I don't have any other symptoms of wet steam, I'm thinking that I am having an "attack of the crappy vents" that managed to fail out of the box. It was only a few vents out of many in the house, and the system is quiet as a lamb, and not one of those noisy lambs that are so popular these days. Of course I'll never be satisfied until the system runs for 50 cents a day and I'm hosting tropical parties with the windows open.
  • David Nadle
    David Nadle Member Posts: 624
    Before you blame the vents

    Do the vents close for a while first and then start to hiss/spit? That could be overpressure. Can you confirm you are cutting out at 12 oz?
  • Elias
    Elias Member Posts: 22

    I've got an oz. gauge, and it does seem to be accurate, but you're right, might as well confirm. I'm going to clean the pigtails, thanks!
  • V8toilet
    V8toilet Member Posts: 71

    I use Maid-O-mist valves on my system and I've installed them on my brother inlaws system. They work fine for me and my brother. Are the Maid-O-mist valves pitched the wrong way on your radiators so that condensate in them can't get out? They do hold some water below the inlet for the valve but never so much that it blocks the airflow. The only way that could be possible is if they are pitched backward or if they don't open after they cool and the system is off.

    I do know they don't like a lot of pressure and if you don't have enough venting or your system builds too much pressure they will sometimes hiss. Mine do not make any noise but on my brothers system they sometimes hiss because his system builds more pressure than mine does.

    If you don't have adequate main venting on your mains than the radiator vents could clog up with debris as the air in the system tries to get out. Without adequate main venting your radiator vents have to vent more and sometimes that causes debris in the system to be driven towards them, which causes them to clog. This is especially true if you are using the C,D, or #6 vents on your radiators. Without adequate main vents they will also tend to be more noisy, which is the case with my brother inlaws system.
  • Fred Harwood_2
    Fred Harwood_2 Member Posts: 195

    You can make your own simple low-pressure gauge to verify your pressure settings and pigtail.
  • LanceT
    LanceT Member Posts: 19

    I am having a similar problem. My vents hiss a little almost immediately then begin to spit water before the rad is even hot (warm though). Once it heats up, things get real crazy with a LOT of water spitting out in some cases... And lots of gurgling and "chinging"... Sounds like a few coins being slammed around inside the rad.

    According to the pressuretrol, the cut-in is 0.5 (I lowered it from 2.5) and the cut-out is set to +1.

    Its keeping us up at night so I need to figure this out soon.

    Btw, many of the valves were replaced with home depot valves. I noticed before connecting the rads that the opening into the rad looked smaller than the old valves. Could this be part of the problem? However, some that are spitting were never touched so they have the older valves on them.

    Also, a lot of floor sanding and drywall work was done. If this dust got into the system, could it be contributing to my problems?

    I will be posting photos tonight or tomorrow.

  • David Nadle
    David Nadle Member Posts: 624
    Check the pitch

    Check the pitch on the radiators with a level. They should have a slight pitch towards the valve. Maybe with the floor refinishing the rads were moved.

  • Elias
    Elias Member Posts: 22

    I think you've got it right on the head. They aren't opening after the system shuts down, mind you just a few out of many. I can remove the screw in orifice and gently nudge the float back down with a pencil. The water inside had sidetracked my thinking. It's definitely not too much pressure. All the risers are master vented, and there are two main vents at the end of the main line. Pressure gauge (it's a 0-30 oz. gauge from McMaster) is reading true, I actually have the vaporstat set at 10 oz. now. I've been moving the same vents around to different radiators, they don't always stick shut immediately (this is after I've nudged the float back down), but I can get the same vents to repeat the sticking after a few cycles.
  • David Nadle
    David Nadle Member Posts: 624

    I'd say it's unlikely that all or most of the radiators would have drain problems at the same time. So if all or most of the radiators hiss, then the boiler is the likely culprit.
  • V8toilet
    V8toilet Member Posts: 71


    If you or someone replaced those radiator valves with the cheap ones from Home Depot than this could be your problem. Those Home Depot radiator valves have a reduced concentric opening that creates a water leg inside the radiator. The undersized opening in conjunction with the water dammed up to the concentric opening can cause water hammer inside the radiator.

    There are of course other causes for those symptoms but if you do have those cheap valves (made in China) than I would replace them anyway with a higher quality valve from your neighborhood plumbing supply store or have a professional replace them.
  • Iwanttobelieve
    Iwanttobelieve Member Posts: 13

    Yep, I thought this was the answer. I was in Lowes tonight for something else and decided to take a look at their valves. They look very different (body of valve is spherical rather than cylindrical and the opening is much larger than the home depot valves. They happened to have one oddball that looked like the ones from Home Depot (someone may have returned it to the wrong store?) and the Lowes guy told me it was a hot water valve, not a steam valve.. which is exactly what I was thinking.

    I know they're still made in china ("American Valve" is the company... right next to that it says "Made in China" :(... but I decided to buy a couple anyway since the supply store was closed.

    I replaced one and....... vent still spits! I also had a leak where the radiator connects to the valve, but I seem to have fixed that by tightening the nut more. I have a bowl under it so I can check for water in the morning.

    Here's another difference: The Lowes valves (wider inside opening) have a different size nut on the 1.75" valve than the Home Depot ones. Now for the aggrevating part... I replaced the spuds on my radiators so that they would connect to the new valves from Home Depot. Now I need to re-replace them with the spuds that came with the Lowes valves. The problem is that the spuds aren't as long and now I can't get any wrench on them to grip them. The spud wrench chewed off the nubs as I expected so I need to find another way to get the spuds off. I'm really trying to avoid cutting the nut off due to the mess and the "no turning back" factor :)

    This is really starting to get to me. I only have 1.5 - 2 hours per night to work on it due to work and the kids' bedtime.

    I also bought two Gorton #1s to install on the main returns, but didn't get a chance. I'm thinking that's not going to solve my spitting vent problems which is the biggest of my problems right now. One of them can go on top of a 6" riser. The other cannot due to a joist. Is it ok to put them on different height risers or should I make them both 4.5 or 5"?

    If anyone has anymore advice, I'll take what I can get.
  • semantics

    for the sake of better communication, let's refer to radiator stop valves [which must never be closed] as valves; and radiator air vents as vents.
    if you have the right low pressure, i doubt you will ever have to change a radiator stop valve [which as you now know should NEVER be closed].
    i am sure you must have over-pressure problems, or wet-steam caused by incorrect piping. do you really know what your pressure is? not just the setting, but the pressure.--nbc
  • Kara
    Kara Member Posts: 36

    They don't have to go straight up. You can "zig" to the side a bit and then up. Here's an example of a "tree " of multiple vents.


    It helps to include a union then you can assemble the "tree" on your work bench and then attach it using the union.
  • Iwanttobelieve
    Iwanttobelieve Member Posts: 13

    Yes, I mean valves. I know that many people say you never need to replace them... but why do they still sell them if that's the case? Are there really new steam systems still being installed? And anyway, they've already been replaced so it is what it is now.

    I had to shut mine off so that the radiators could be removed so that the floors could be refinished. Many had broken handles, and most leaked out of the stem or other places so I figured it made sense to replace them.

    I am aware that they cannot be partially open. They are all fully open except for two which are fully closed because the radiator is still not connected.

    My leaks are occurring at the vent. Water is coming out of the vent hole, not from around the threads.

  • Tim_64
    Tim_64 Member Posts: 76

    This past summer I redid my steam heat system....

    I bought the made-o-mist vents from Home Despot.. to use while the system was "steam cleaned"

    Some of these vents lasted a few cycles, others never worked at all...

    So my inner geek demanded I dissect one.... The inside of a maid-o-schist vent is some sort of cheap plastic....

    Buy a Gorton
  • David Nadle
    David Nadle Member Posts: 624

    I'm not a pro, so accept this advice with that in mind.

    First, the brand of vent is not the problem. The vents are not the problem.

    Second, if you can't get a main vent on a 6" nipple just go as high as you can. The nipple is to protect the vent from damage by water hammer. The longer the better but even with no nipple you may never break a vent.

    The fact that your vents are spitting water when the radiators are still cold indicates to me that you are making wet steam from the boiler. You may have a piping problem, or dirty/oily water. Post pics of the near boiler piping and consider skimming the boiler a few times.

    On the rad you put the Lowe's valve, remove the vent and drain any water out, then replace it. You may have had residual water in the vent that masked a successful fix.
  • LanceT
    LanceT Member Posts: 19

    Good idea about the vent. I will try that tonight.

    See this post for pics of piping:
  • LanceT
    LanceT Member Posts: 19
    I've been beat

    I emptied the vent (was fully of water) and replaced it with a new one that I knew was clean and dry. After maybe two cycles, it began spitting water as well.

    I really don't have the time to experiment with skimming. We have a house full of boxes to unpack and 5 children that are expecting a Christmas tree (gotta unpack to find room for it). Plus it's cold weather season so I can't really afford to screw it up more and be without heat.

    I think I need to have someone come and look at it.

    Thanks everyone for your help.
  • David Nadle
    David Nadle Member Posts: 624

    Hope you find somebody great to help you out. Try the "find a professional" feature on this site if you haven't already. Come back and share what you learn from the fix. And remember, there's always next season!
  • LanceT
    LanceT Member Posts: 19
    wet steam but no surging

    So to followup on my own thread.... I recently had a radiator disconnected so I turned on the heat and opened the shut-off valve until steam came out. As soon as steam started coming out, water also started pouring out of the valve. This isn't normal, right? This is "wet steam" I'm presuming? It would make sense considering my problems with spitting vents (see previous posts in this thread).

    The problem though is that the water in my sight glass is NOT bouncing up an down. Could I still need to skim? Or could it be something else? Photos of the near-boiler piping have been posted earlier in this thread... nobody said anything looked wrong. Can you all take another look at them?

    What else can cause wet steam?
    - oil in the water: water not bouncing in glass
    - high pressure?: I lowered the pressuretrol to 0.5 and +1
    - bad near boiler piping: I need someone to view the photos and tell me that's not it
    - what else?

  • steam valves

    did you check your valves for "fallen disk syndrome"? what can happen is the disk [like a washer] comes off, and can cover the valve exit, allowing steam in, but not allowing the condensate to get out.

    you can check this by removing [ boiler off!] the valve bonnet, and unscrewing the stem until it comes out, and have a good look down inside the valve body.--nbc

  • Lance-
    Go back to the post that has your pictures

  • Lance-
    Go back to the post that has your pictures and read back in that thread to a reply from me about your boiler piping and the suggestion that you probably need to use the other steam port in your boiler.

    I have attached a picture of what might be called "the ideal header". I save pictures like these for further reference. I'm afraid I don't remember who did it. I tried to look back and find the thread. It was one of the steam pros on this board. Beautiful work! Also notice how the risers, from the header to the main, are angled so that any condensate drains back easily.
  • LanceT
    LanceT Member Posts: 19

    No, this is not the problem. With the shutoff valve fully open and no radiator connected, water and steam come out of the valve opening at exactly the same time.

    Remember, I have this "vent spitting steam" problem on most of my radiators (3rd floor excluded -- maybe the water isn't being pushed up that high? as well as some radiators with old vents -- the vents also don't let much air out so I think they need to be replaced anyway).
  • LanceT
    LanceT Member Posts: 19

    Yes, I did note that. However, I thought using both steam ports would be ideal but probably not causing the problem I'm having.

    The problem is that we just moved in and I don't know who installed it and I don't know of anyone in the area that is good with steam. I've used the search on this site, but there are no ads in my area.

  • V8toilet
    V8toilet Member Posts: 71

    The pictures of your near boiler piping show that you don't have any pipe insulation. A steam pipe that isn't insulated looses 5 times as much heat as an insulated one. The steam in an uninsulated pipe condenses the steam creating a lot of condensate and possible more condensate than the pipes can handle.

    If you haven't insulated your steam pipes you need to do that with a least 1" fiberglass insulation.

    Also do you have a counterflow steam system of a parallel flow steam system? In a counterflow system the mains pitch back toward the boiler header, in a parallel flow system the mains pitch away from the header and there would be a smaller return line connected at the end to return condensate back to the boiler.
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