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Please Help - Leaking Hy Vent

Peter OC
Peter OC Member Posts: 3
Can someone please give me some advice on how to handle a leaking Taco Hy Vent??? Thanks!


  • lchmb
    lchmb Member Posts: 2,997
    where is it leaking?

    Is it leaking out of the air release valve or the seat? You can alway's close the hy vent but should get it replaced when you can. If it's leaking at the seat then it will have to come out to be replaced...:)
  • Speaking of Taco vents

    Every one of them we installed in the past few month have given us trouble at the vent cap . We cannot hand spin them closed anymore . You need pliers to close the little cap . Whats up with that ?
  • lchmb
    lchmb Member Posts: 2,997

    And not sure why but the last dozen I have put in let a little air out and then look like a water fountain. Sent them back to my supplier but not sure what's going on. Must be the hard mountain water up here..:)
  • Steve M
    Steve M Member Posts: 26
    From the hy-vent instructions

    "After system is filled, loosen cap slightly and allow air to be released slowly, otherwise scale and dirt might rush in causing valve to leak. If this happens, push down valve stem then pull uplightly to dislodge scale."

    "For normal venting, open cap one full turn."

    Make sure the cap is closed until you're ready to fill the system.

    Good luck
  • lchmb
    lchmb Member Posts: 2,997
    been there

    Done that...have the t-shirt to prove it..But, since I like the taco's better than anything else, we'll keep chuggin along..;) Could be I had a bad week..:o
  • jerry scharf_2
    jerry scharf_2 Member Posts: 414
    opinions on the least likely to leak air vent

    I have a situation where I would like to put a vent but it would really be a pain if it leaked. What are people's experience on which one does best on this front.

  • Bill_39
    Bill_39 Member Posts: 69
    replace it

    replace it
  • Glenn Harrison_2
    Glenn Harrison_2 Member Posts: 845
    My opinion,

    1. Spirotop, made by Spirotherm. 1/2" Female pipe thread connection. Also has a 1/2" male pipe thread connection on the top of the vent so you can connect piping to a less damaging location.

    2. Honeywell EA122 airvent. The vent can be turned off with in itself and the top valve can be removed and cleaned to prevent plugging.
  • jim murtaugh
    jim murtaugh Member Posts: 72

  • Glenn Harrison_2
    Glenn Harrison_2 Member Posts: 845
    We used to use Dole 2000

    vents and they constantly leaked. Then our main supply house started carrying the EA122 units. We switched to those and have been so happy ever since.
  • jerry scharf_2
    jerry scharf_2 Member Posts: 414
    thanks for the response

    Just what I was looking for.

  • Glenn Harrison_2
    Glenn Harrison_2 Member Posts: 845
    My pleasure, Jerry.

  • Joe Mattiello
    Joe Mattiello Member Posts: 693
    Taco Hy-Vent

    Good Morning
    Taco Hy-vents have been the industry leader for over 30 years, and have been proved to be of high quality, over, and over again. They may leak at times when system debris collects in the cylindrical body hindering the valves performance. One of the attributes of the Taco, hy-vent, is that you can take the top part off, clean out the body, reassemble it, and put it back in service. If the vent is installed in an area where some water that leaked would do harm, Taco offers a waste connector that attaches to the threaded connection, and can be run to a nearby sink, or drain. Hopefully this clears the air.

    Taco, Inc.
    Joe Mattiello
    Technical Service Technician
    [email protected]
    401-942-8000 X 484
    Joe Mattiello
    N. E. Regional Manger, Commercial Products
    Taco Comfort Solutions
  • TACO HY_VENT 400 leaking

    I have several TACO HY-VENT 400 bleeders.  Yes, I can screw the top cap off and clean out the vent.  I use a toothbrush to clean the body and scrub the valve assembly.  I actually disassemble the spring assembly and scrub down all of the parts. 

    However, they work OK for a short time and then they start leaking again.

    I am looking for a more reliable bleeder.  It sounds like the Honeywell EA122 is popular in this thread.
  • Also looking for a taco hy-vent replacement

    I have several taco hy-vent 400 bleeders.  They work for a time and then they all leak.  I open the top, remove the float and spring valve assembly, take everything apart, and scrub down all of the parts with a toothbrush. 

    This works for a short time, and they start leaking again.

    It looks like the Honeywell EA122 is a popular replacement in this forum.

    I am looking forward to trying it.
  • icesailor
    icesailor Member Posts: 7,265
    Leaking Vents:

    After changing float vents by the gazillion when leaking around the cap, I started screwing them down tight. I've never had an issue with air stopping the flow.

    I found that the biggest culprits were the ones on the supply side, close to the boiler. Hot water got under the seats and evaporated. Leaving a white residue behind that finally caused the leaking valve. The same kind of leak caused when installers use red rubber circulator gaskets in place or in conjunction with the square cut O-rings supplied by the manufacturers. The same square cut O-rings used by boiler manufacturers on tankless plates. The red rubber gets as hard as the tar road and then cracks and leaks.
  • meplumber
    meplumber Member Posts: 678
    Supply side Hy vents.

    My friend icesailor is dead on.

    I put my hy vents on the return side at the last 90 as it returns to the boiler. Of course, I have the one Hy vent at the Air Scoop on the supply side, mostly for filling, but I isolate it with a Raven valve.

    By exposing the Hy vent to lower water temps, I have seen a drastic drop in Hy vent failure over the years.

    Putting a Raven valve on the air scoop is the only way to go. Every time I replace a Hy vent, a Raven goes in with the new one. This keeps me from having to drop system pressure when servicing or replacing the Hy vent.

    To the OP's question, they all leak. It is usually caused by dirt or long term exposure to high water temps. I have used them all Taco, Caleffi, Honeywell, Baukmann, Dole, etc...etc....
  • jboissy16
    jboissy16 Member Posts: 11
    RE: Replacing Taco 400 Air Vent

    When replacing a taco air vent can I just isolate it where the values are, drain that section where its isolated replace it and open the values and thats it. Or Do I have to purge the entire system. Whats steps should be taken 
  • Bad_product
    Bad_product Member Posts: 1
    Taco 400 leaking

    Yes I have cleaned and replaced about 10 of these in my won house and constantly leaking. They are garbage and I will be trying the Honeywell one as no matter where I install the Taco ones, they start leaking after about a month. emailed Taco  and no responce. Guess they do not care.
  • icesailor
    icesailor Member Posts: 7,265

    They won't leak if the caps are down tight. If they start leaking because of loose caps, the pressure is too low in the system and/or the boiler is set too high.

    In my career, I replaced hundreds of them. Some, every year. I never had to purge anything because of no flow. I started tightening down the caps and the problem of musical vents went away. The only vents I put on baseboards were Jet Tees with the caps to vent or shut up others. I never used them. Once the system had its initial purge and started working, it never stopped for years and years.
  • hot_rod
    hot_rod Member Posts: 20,826
    a very simple device

    A stem, and an o-ring seal, are the shutoff mechanism.

    It doesn't take much to cause them to seep, a grain of sand in that seal an do it. Dirty fluid is a main cause of leakers.

    You could add a hygroscopic cap for a second level of shut off protection.

    This Caleffi cap is ordered on many vents, it should fit other brands.
    Bob "hot rod" Rohr
    trainer for Caleffi NA
    Living the hydronic dream
  • icesailor
    icesailor Member Posts: 7,265
    Moisture and dirt:

    I could never ever find any dirt under the seats. It was always where water evaporated at the closest tight spot and the gasses escaped through the seat. As time and gasses evaporated and seeped out, it left formerly dissolved solids behind that finally fouled the seat letting more and more evaporated  water past. All that white crud around the tops of the cans is just the same stuff as if you billed all the water out of a pan on the stove. The same stuff that leaks out of a red rubber gasket once it gets as hard as a tar road. It never appears to be leaking when the boiler is hot. Let it get cold like a cold start boiler and you see water running down around the gaskets and bolts.
  • icesailor
    icesailor Member Posts: 7,265
    Repair Parts:

    Are you a Rep? Did I see you in a video?

    My experience is that no one today wants to fix anything, just replace it. No supply house wants to stock repair parts or order repair parts unless I do the leg work and give them the accurate parts number. And when the parts come, they are usually more than the cost of a whole replacement.

    For example, If I had a Taco 572 zone valve that has a leaking and sticking cartridge seal, I could wait 2 weeks for a replacement plunger assembly. Immediately, on the shelf, I could get a whole new valve and take the plunger out of a new one. Save the power head for when I had a bad one, and throw the body in the brass barrel. I could replace the plunger in less than an hour without draining the system. Replacing the valve could easily be a 3 hour process. What you can sell the parts is more than equal to the whole valve and more. As far as #400's, the parts are more than the whole valve. I can change a #400 "on the fly" in a less than a minute. It takes far more time to repair a leaking #400. I will repair anything. If you charge $60.00 per hour, that's $1.00 per minute. It doesn't take many minutes at $1.00 per minute to eat up the cost of a new #400. IME
  • hot_rod
    hot_rod Member Posts: 20,826
    I consider it a consumable

    part, those small air vents., it will need service or replacement, just like a thermostatic valve or any other tight tolerance valve.

    I'd call that white crud dirt, or minerals, I suppose. The only way to avoid it is fill the system with de-mineralized water.

    And some contractors do fill with DM water that they filter at the job site.

    That small Sorbox recently shown here demineralizes fill water for small systems. Several other manufacturers are bringing out small DM systems that connect by the fill valve.

    It is wise to use DM water for blending glycols on the job site, Dow requires it.
    Bob "hot rod" Rohr
    trainer for Caleffi NA
    Living the hydronic dream
  • billtwocase
    billtwocase Member Posts: 2,385
    done with taco 400

    after too many leakers, and closing the cap does not get the customer thru the night anymore, I have gone to Amtrol 700 with good results so far. They changed manufactures, and they don't have a clue how to build them evidently 
  • icesailor
    icesailor Member Posts: 7,265
    edited August 2014
    Hy Vents:

    What's the difference between Taco #400's and Caleffi? The really old Taco vents were made by Taco. Then, they were made in Italy and look like the ones today. At a greet and eat at the supply house, a Caleffi Rep was showing off Caleffi vents. They were the same.

    If you purge properly, and have sufficient system pressure and a large enough expansion tank, you should NEVER have any air appearing in the system or need automatic vents.

    I must have worked in a parallel universe because I never was plagued by air like I see here. If the system pressure is high enough, it squishes the bubbles so they are absorbed.
  • Big_Drip
    Big_Drip Member Posts: 1
    I've been replacing the Taco Hi-Vent about twice each heating season. Same problem; water weeping through the cap. I read some of the comments on this string and purchased a Honeywell EA122. Installed it as described in the instructions then purged the air and dirt out of the system.
    For the first time that I can remember -- and I've been in this house for a very long time -- the pressure rose in a steady and slow fashion. and the entire house -- every room -- was warm! That hasn't happened, ever!
    Now that everything seems to be working properly I have found that the over pressure valve is weeping . . . Calling the plumber in the morning!
    Thanks for the great advice!
  • Intplm.
    Intplm. Member Posts: 1,618
    Mostly on commercial installations, and a few on residential installations , I have installed them with a small shut off valve for reasons just like this. I usually will install a valve under a vent when it makes the change that much more convenient.
  • ch4man
    ch4man Member Posts: 294
    could always just properly install a scoop, tank fitting and an old school compression tank and be done with it. done right they're pretty reliable........
  • hot_rod
    hot_rod Member Posts: 20,826
    All brands will be sensitive to crud in the fluid. Chose one with either a service check, or valve below if you have poor fluid quality, knowing that they willed service. Especially important on old iron radiator and steel pipe systems as they will flake off scale forever.

    Also make sure you have some positive pressure on the vent. the float should be adequate to seal of the valve, a few- 5psi or more adds some force to get a tight seal.

    As noted above, an additional hydroscopic cap, or vent tube will prevent damaging anything in the path of the discharge.
    Bob "hot rod" Rohr
    trainer for Caleffi NA
    Living the hydronic dream