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first day with new vent mains and vaporstat

bbillcee
bbillcee Member Posts: 65
edited January 27 in Strictly Steam

hi guys

so yesterday i finished adding some vents to the mains and vaporstat. i set vaporstat(0-4psi) at 1 psi with 8oz diff.

yesterday the temperature was maintained without ever coming near the .5 psi. cut out (i have 3 psi gauge installed). So i was looking forward to stare at the boiler the AM to watch the recovery from 69 to 71. I usually do 68 at night but didnt want to push that much today. so the boiler ran till thermostat temp got about 70/70.5 till it hit the cutoff, pressure dropped quickly but also raised quickly when it come back on so the boiler ran for maybe 2-3 min before hitting the cutoff again…it did that twice before the thermostat was satisfied. I guess thats short cycling? any recommendations to make to vaporstat? 1 pipe steam weil McClain

Comments

  • AdmiralYoda
    AdmiralYoda Member Posts: 713

    Yep, this is short cycling. But I wouldn't worry about it as it sounds pretty typical for an oversized boiler. What is your measured radiator EDR and the capacity of your boiler?

    I have an oversized boiler and I've installed a vaporstat. I cycle on pressure when it gets below 30F outside. Some things to consider:

    1. Perhaps raise your cut out pressure a bit to say 12-14oz and your differential to 8-10oz less than your cut out. Still very reasonable pressures and the wider differential gives the boiler a bit more time between cycles.
    2. My system works best when I "set it and forget it". I've found no measurable financial savings when using setbacks. I keep it at 68F and it cycles much less, especially since there is no recovery. Perhaps on a perfectly sized and balanced system this wouldn't apply but on my oversized system it does more harm than good.
    delcrossv
  • bbillcee
    bbillcee Member Posts: 65
    https://forum.heatinghelp.com/discussion/comment/1838180#Comment_1838180

    hey thx for reply

    I never did the calculations (complete laziness) but am pretty sure it’s oversized.

    I’ll try your recommendations. What would be acceptable amount of time to run after it atarts again?

    I’ll also have played around with leaving it on 70 all the time, might just do that

  • EBEBRATT-Ed
    EBEBRATT-Ed Member Posts: 17,233

    Your fine a couple of short cycles coming out of set back is fine. Sounds like you did the right thing.

    If it short cycled all the time that would be different.

    ethicalpaulbbillcee
  • Jamie Hall
    Jamie Hall Member Posts: 25,624

    You're fine. it's running as it should, given the boiler vs. radiation sizing.

    Br. Jamie, osb
    Building superintendent/caretaker, 7200 sq. ft. historic house museum with dependencies in New England
    bbillcee
  • bbillcee
    bbillcee Member Posts: 65

    i increased the set back a bit (also back in the 20's today)and it short cycled 5 times but still satisfied the thermostat….is that still acceptable?

  • Long Beach Ed
    Long Beach Ed Member Posts: 1,638

    The setback may be costing you money.

    Waher
  • ethicalpaul
    ethicalpaul Member Posts: 7,309
    https://forum.heatinghelp.com/discussion/comment/1838915#Comment_1838915

    Acceptable is up to you to determine. I assert that for atmospheric gas steam boilers, the term "short cycling" doesn't really apply. If you can't notice it while sitting on your couch, it's fine.

    NJ Steam Homeowner.
    Free NJ and remote steam advice: https://heatinghelp.com/find-a-contractor/detail/new-jersey-steam-help/
    See my sight glass boiler videos: https://bit.ly/3sZW1el

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