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Frequency of refilling the boiler

Hi all,
I have a old gas boiler with a manual water feed. Here in NY the temps have been hovering around the single digits and with the wind chill it can go below 0. I'm wondering when it's this cold what would be considered a normal refilling frequency? I do not see any steam coming out of my chimney and I believe I addressed all leaks and it appears that I am filling every 2 days. Thoughts?


  • JStar
    JStar Member Posts: 2,752

    You can overfill the boiler, above the top, to check for leaks.
  • Jamie Hall
    Jamie Hall Member Posts: 23,275
    Cold here, too. As a gauge, the system I care for has taken eight gallons of water since it was installed, 4 years ago...
    Br. Jamie, osb
    Building superintendent/caretaker, 7200 sq. ft. historic house museum with dependencies in New England
  • hwangnyc
    hwangnyc Member Posts: 18
    Jamie, that is incredible! I hope I'll be able to get my boiler to that efficiently one day.

    At this point, I can't overfill the boiler. It's just too cold and seems like a task I need to learn more about. A few weeks ago, I made the mistake and left the water on instead of turning it off on one of my routine fillings. It overflowed to the point where it started shooting out the pressure release valve on one of the radiators.

    JStar, would you be able provide me with a bit more information on the procedure?
  • ChrisJ
    ChrisJ Member Posts: 15,664
    I add around a quart after a cold month. We had -8F this morning and no noticeable change in water level.

    Remember, both the boiler and steam pipes can slowly leak without you seeing it because it can evaporate as fast as it leaks.
    Single pipe quasi-vapor system. Typical operating pressure 0.14 - 0.43 oz. EcoSteam ES-20 Advanced Control for Residential Steam boilers. Rectorseal Steamaster water treatment
  • wmtandson
    wmtandson Member Posts: 62
    Just remember ,the boiler needs sufficient room to produce steam.
    Also overfilling can cause damage to the pressure controls ,so exercise caution
  • When it's really cold out. I add about 2 inches of water (measured on the sight glass) every month. Don't know if it's too often.
  • Fred
    Fred Member Posts: 8,542
    Except for the blow downs I do, every couple weeks, I haven't had to add any water yet this season but it has been mild here so far this year. I typically might have to add about two quarts a month when we have sub-zero temps. It's a large boiler though, rated at 866 sq. ft. of steam.
    It would be interesting to note when the weather there gets warmer and the boiler gets a chance to sit idle for a few hours, if the sight glass fills above where you normally fill it to. May be slow wet returns due to sludge build up.
    Do you have the pressure set low? .5 PSI cut-in and 1.5 PSI cut-out. High pressures can also contribute to steam escaping a bit from both main and radiator vents. Usually not enough to visably notice but they will leak.