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VXT went from feeding lots of water to none- is that concerning?

bipbap Member Posts: 191
Hey All,

  So I posted last winter after I installed a VXT and could finally track my water use.  From the responses it seemed like it was on the high side for added water but without any visible leaks I wasn’t sure what to do.  It had fed about 11 gallons in two months from Feb to end of March in NYC winter.

  Now the weird thing is for the rest of that season starting in April through end of May and for the past few weeks of this heating season, it says it hasn’t needed to feed any water- not even 1 gallon.

  This seems strange to me. Why would a system that was needing more water than usual suddenly now need no extra water?

  The water level in the sight glass seems fine so I don’t think it’s malfunctioning but it just seems odd. My steam guy said sometimes a connection where it had been leaking steam could have rusted over and sealed itself. But any leak that once needed so much extra water seems like it would be too big to close itself over? But again I’m no pro.

  I posted my previous message from last winter below with the water usage I had been having if helpful.  Would love to hear any ideas.  
  Now I’d love if everything was magically working great and I now magically have a sealed up system that doesn’t need added water but it just seems strange to me when I didn’t do anything to cause this change- it literally went from needing lots of water to then needing no water.

Previous post:
So after all the good advice I got here, about 2 months ago I replaced a failing water feeder with a VXT and can finally see real data on make-up water. I tracked it and here's what I recorded, I just don't know how good or bad these numbers are and am wondering if this is normal or if I should be doing something to reduce the water loss, even though there are no leaks or drips anywhere obvious, though some air vents might be old.

Feb 5: 10 (was at 10 when plumber finished installing)
Feb 7: 11
Feb 14: 11
Feb 16: 12
Feb 19: 13
Feb 21: 15
Mar 1: 16
Mar 5: 17
Mar 14: 19
Mar 28: 20
Mar 29: 21
Mar 31: 21

I didn't add any water or flush out any dirty water in the past 2 months, so it fed itself 11 gallons in about 2 months. That sounds like a lot (?) but we do have a large boiler and it has been cold in NYC in that time. This is a small multifamily with single pipe gas steam.

Boiler model was asked for last time I posted and it's a Weil-McLain EGH-105-PIN and it says gross output is 360k BTU, input 450K BTU if that is helpful.

Thanks in advance for your thoughts


  • KC_Jones
    KC_Jones Member Posts: 5,261
    Sounds like it relates to outdoor temperatures. The more the boiler runs the more water you lose.

    I'd be looking for steam leaks. Keep in mind, steam is invisible so they can be challenging. A mirror can be your friend here. Bad vents, valve packings are the two big hitters here.
    2014 Weil Mclain EG-40
    EcoSteam ES-20 Advanced Boiler Control
    Boiler pictures updated 2/21/15
  • bipbap
    bipbap Member Posts: 191
    edited November 16
    Yes I see how it could be affected by how often it runs but I figure maybe it’s still using a gallon here or there but not using ANY water seems strange because it’s still running a decent amount even if less that the coldest months.
  • ethicalpaul
    ethicalpaul Member Posts: 3,929
    The cheaper way to track your usage is to not buy an auto feeder at all and check the water weekly and manually add what is needed. I know this won’t help you but maybe the next person
    1 pipe Peerless 63-03L in Cedar Grove, NJ, coal > oil > NG
  • Long Beach Ed
    Long Beach Ed Member Posts: 796
    The best way to tighten up a single pipe system is to remove the vents, plug the ports and pressurize it with a few pounds of air. You'll be amazed at the leaks you'll find. Every radiator valve stem can be tightened as they all leak, and usually the sight glass is leaking too. Who knows what else! And if those vents were last replaced in 1945 or made in China, they leak also, so you might replace them if they fail to close.
  • bipbap
    bipbap Member Posts: 191
    I’ll keep an eye on it as colder weather sets in and it runs more and report back  
  • SteamingatMohawk
    SteamingatMohawk Member Posts: 790
    If you use Heat Timer Varivalves, when they are fully shut, they aren't. At the SHUT position, they vent at the rate of a #5. This is somewhat common knowledge in multiple discussions over the years.

    Having no idea what vents you use, even though this just popped up in my head, I decided to mention it anyhow. Is it happy hour yet?

  • bipbap
    bipbap Member Posts: 191
    Thanks for the tip but these are just plain old Gorton vents on the radiators.
    But the building has about 21 radiators and vents so lots of places for leaks I guess.