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Single pipe steam radiator air vents cleanable or better to buy new after a few years?

cubicacres Member Posts: 341
After replacing all 22 of our single-pipe steam radiator air vents (mostly Dole 1933 vents from the 1980s-early 2000s) with new ones (new ones were all new Hoffman 1A vari-vents) in our 5 unit apartment building in 2015 at the same time as our new boiler (a WMC EG75 install), we noticed about 5-7 of the vari-vents failed since 2015 over the past 6 years & seemed to not close at all, letting the radiator end & vent get over 200F & leak steam/mist/sputter water down the vent & into the hotter than desired tenant's rooms. We think this is a source of some of our higher water use when we find & replace them over time & note the water use dropping in our boiler notebook log.

We cleaned the vari-vents in vinegar & replaced them after a cleaning & also tried some other brands of new vents (not the same vari-vent model-cheaper $10 ones from HD & local hardware stores) & also cleaned the old Dole 1933 vents that were in the building the past several decades & put them on, but were wondering if you can really clean a used vent as well as just buying a new one when they go bad?

I'd like to think we can save the $35 cost of a new vari-vent by cleaning the ones we already have, or the $10 that the cheaper ones are at our local hardware stores if they're acceptable to use after cleaning them or older Dole 1933 vents, but when we watched the 2015 cleaned vari-vents & older 1980s-2000s Dole vents we cleaned work for a cycle, then stayed open the 2nd cycle & didn't close, we were dissapointed at the lack of reliability in closing properly & thought it would be worth it to save time to buy new each time they failed.

Any advice about cleaning & using older radiator air vents, or is it best to buy new when they fail every few years out or so? Or could the specific radiator or pressure be clogging certain ones faster than they should be?


  • Steamhead
    Steamhead Member Posts: 15,028
    I'd suggest switching to Vent-Rite #1 vents. These are easier for tenants to adjust, and seem to last longer.

    ISTR the boiler is controlled by a Tekmar or Heat-Timer unit. If there is an indoor temperature sensor, the radiators in that area should have fixed-port vents.
    All Steamed Up, Inc.
    Towson, MD, USA
    Steam, Vapor & Hot-Water Heating Specialists
    Oil & Gas Burner Service
  • NHOwner
    NHOwner Member Posts: 77
    I think you should use Maid O Mist steam air vents. They are good and cheap imo. I had a Gorton #1 that was hissing all the time. I bought a Maid O Mist. Pushes the air out and stays quiet. If it is pushing the cold air out and then close, then it's good. I'd keep. If not, i'd replace.
  • cubicacres
    cubicacres Member Posts: 341
    Yes, we have a Tekmar with 1 indoor & 1 outdoor sensor. We can check to see that room with the indoor sensor is a fixed-port, not variable vent air vent on the radiator. We also have the air vent sizing chart booklet Dan H. reccomended a while back, so we'll check for smaller fixed vents where variable ones aren't reccomended in rooms that are getting too hot on the 2nd floor or have smaller radiators.

    Is this good way to lower the room temp if too warm for comfort in certain rooms? We also have shut-off levers to stop air from getting to the vent as reccomended earlier on this site instead of using the old floor valves that often don't seal very well.

    Once a vent seems to stay open, is it just a piece of recyclable brass scrap, or is there a way to clean/repair them? If new ones are more reliable, I think it's worth getting them rather than spending a few hours watching & cleaning the old ones multiple times over the next few heating seasons.
  • NHOwner
    NHOwner Member Posts: 77

    We also have the air vent sizing chart booklet Dan H. reccomended a while back, so we'll check for smaller fixed vents where variable ones aren't reccomended in rooms that are getting too hot on the 2nd floor or have smaller radiators.

    Ok. I don't understand this. Fix vents for rooms that are too hot? I use Jacobus Steam Vent Model 5 all first and second floor. 2nd floor is too hot. Are you saying use fix vents on the 2nd floor to solve this problem? What are they and can you recommend?
  • cubicacres
    cubicacres Member Posts: 341
    edited January 12
    The theory I'm hoping to verify here with more experienced professionals advice is that slower/smaller radiator air vents take longer to heat up the radiator sections, making for a slightly cooler room with less heat over time/multiple heating cycles. Each vent has a different flow rate of evacuating air & letting steam enter the radiator per manufacturing specs & tested research papers out there.

    Our small bathroom half-size radiator at the end of the line seems to get hot all the way across & cook the air vents to 215F each time we replaced them when they leak & sputter, so not sure if they were all clogged vents we kept swapping out with other clogged ones since they were not new but soaked in vinegar & passed the "blow into it test" by us (air flows through it when right side up & not when held upside down), or if that small radiator has other problems that take out all the air vents we tried.

    Or are larger air vents usually better if they clog less often with rust/particles? We could simply do an on/off lever between the vent & radiator space with the 1/8" run of pipe we used on a few of the rooms that were too hot, effectivley letting the tenants shut off a few of the radiators on the 2nd floor.
  • SteamingatMohawk
    SteamingatMohawk Member Posts: 505

    Attached is a chart I made up using the Pajek report data and some additional information source(s) as noted. I attempted to make a comparison of some of the most common vent valves. Take a few minutes and review not only the bars, but the text, because that helped me to get across some of the important features of some of the valves. I don't have any comparison for the copycat vents, your guess is as good as mine as to their flow capacities and reliability.

    I now use Vent Rite #1s for the lower range, because it can be completely shut off and Heat Timer for the higher range because of its high capacity.
  • cubicacres
    cubicacres Member Posts: 341
    Thanks for the chart-I think we had the Gill/Pajek one in the past. We'll try the Vent-rite #1's as Hoffman 1A vari-valve replacements. I'd agree that those numbers on the bottom are easier to see for tenants to adjust compared to the small stamped #1-6 on the Hoffman 1As that often need a small wrench to loosen & adjust the top. I think Maid-o-mist is also called Jacobus in our area per some online websites I've seen. Interesting that Jacobus/Quickflash? was an oil/heating company I remember seeing trucks in the Milwaukee area several years ago.
  • tommay
    tommay Member Posts: 26
    The older ones are the better ones, especially if adjustable. Shake out any water and spray in a little WD40. Newer box store ones, like most things today are junk.
  • Gary Smith
    Gary Smith Member Posts: 374
    What is the boiler pressuretrol set at, and is the pigtail clean? Maybe you are over pressuring the system and causing the vents to fail prematurely.