Welcome! Here are the website rules, as well as some tips for using this forum.
Need to contact us? Visit https://heatinghelp.com/contact-us/.
Click here to Find a Contractor in your area.

Spitting Maid-O-Mist air vent problem

Options
bipbap
bipbap Member Posts: 191
in Strictly Steam
We have an air vent on one of the radiators on our one-pipe steam system which is spitting a lot, like a small puddle under the radiator.
It says it is a Maid-o-mist self-adjustable air vent.
Any suggestions?
We have a vaporstat set at MAIN 12oz and a DIFF of 7oz so figured it wasn't a pressure issue but we're new to this.
Thanks for any advice!

Comments

  • Kahooli
    Kahooli Member Posts: 112
    Options
    They can fail over time (or for any reason at any time). Buy a spare vent and swap it out.

    I like the hoffman 1A and the heattimer varivent
  • nicholas bonham-carter
    nicholas bonham-carter Member Posts: 8,576
    Options
    You should have a low pressure gauge, (Valworx, 0-3 psi), just to keep the vaporstat honest.
    Observing the pressure as the air is escaping will show you how effective your main vents are. which may be your problem.--NBC
  • Fred
    Fred Member Posts: 8,542
    edited November 2017
    Options
    Hoffman 1A or Vent-Rite #1 are both very reliable adjustable vents. Many people have a problem with the Heattimer Varivent as they tend to spit water too. Whatever you do, don't buy the cheapo's from Home Depot or Lowes. They are a Chinese knock-off and a waste of time and money. Maid-o- Mist is a good vent also, if you want to replace it with another one.
  • STEAM DOCTOR
    STEAM DOCTOR Member Posts: 1,973
    Options
    Might not be a vent problem. There may be excess water in the boiler or something might be trapping water in that radiator etc...
  • bipbap
    bipbap Member Posts: 191
    Options
    Thanks for the ideas.
    It is on a big radiator in a small room, ground floor almost closest to the boiler.
    The vent hasn't been changed in the 10 years or so I've lived there.
    I did have a reputable steam guy (from this site) add a number of vents to the basement mains so I can't imagine it's that.
    I also have a low pressure gauge 0-3psi so will watch that next time.
    I feel like I've addressed most of the other issues,
    so can a spitting vent just be a sign the vent needs to be replaced?
  • MilanD
    MilanD Member Posts: 1,160
    Options
    bipbap said:


    I feel like I've addressed most of the other issues,
    so can a spitting vent just be a sign the vent needs to be replaced?

    Yes it can.

    Also, it can hold condensate due to some debris being blown into it over a period of time, so unscrew it, shake it out, blow through it in up-right, then upside down direction and see if it closes when turned upside down. Then reinstall and see if it stops spitting. If not, get a new one.

    Just be careful not to cross threads when threading it back into the radiator. Easy to do if not being careful.
  • bipbap
    bipbap Member Posts: 191
    Options
    Ok, I'll give that a shot.
    And if it needs to be replaced, any suggested type for that location and size radiator?
    I've replaced others with various types of Gortons but not sure if that's the best option.
  • BobC
    BobC Member Posts: 5,478
    Options
    Check the radiator with a level to make sure the radiator is sloping back towards the input valve. What size orifice is on that vent?

    Usually you vent radiators proportional to their EDR and the surface area of the radiator runouts, small radiators get small vents and large radiators get larger ones but remember don't go overboard. You want to vent the mains fast and the radiators slowly.

    One of these will let you play with the orifice size and it's dirt cheap.

    https://www.amazon.com/OMIST-0220-5L-Angle-Steam-Valve/dp/B003DV3AGE/ref=sr_1_1?ie=UTF8&qid=1510350956&sr=8-1&keywords=maid+o+mist

    Bob
    Smith G8-3 with EZ Gas @ 90,000 BTU, Single pipe steam
    Vaporstat with a 12oz cut-out and 4oz cut-in
    3PSI gauge

Categories