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Pressuretrol working or not working



  • J.D.Sarick
    J.D.Sarick Member Posts: 13
    Pressuretrol working or not working

    I have a programable thermostat so I can turn the heat down to 58°F during the day and at 5pm it goes back to 68°F. When the furnace begins to boil, I can hear the main vents releasing the air from the system as the steam pushes through. After 20 to 30 minutes the main vents are quiet. At this point I assume all the steam traps have been activated and I expect to see a spike in the pressure gauge near the pressuretrol which would shut off the boiler until the pressure dropped back down to below 1/2 psi. This isn't happening. The boiler continues to run and the gauge never comes off zero. Is there a way to check of the pressuretrol is working correctly? Also, the gauge comes off a T below the pressuretrol and when I remove the gauge I don't feel any steam rising out of the copper loop. Should the copper loop be empty of water or should the lower half of the loop have fluid in it to keep the hot steam from getting to the pressuretrol?
  • Brad White_36
    Brad White_36 Member Posts: 30
    Sounds like

    it might be the gauge or installation of it. See if the siphon is plugged. The water seal in the loop is intended to keep steam from hitting the gauge mechanism directly.

    Without a gauge there is no way to say what the pressuretrol is responding to. Absent that, does the boiler cycle reasonably and does the house heat quickly enough for you?

    Replacing the gauge is a good thing to do. If you can get a large face gauge (4.5 inches scale) is a 0-5 psig range, that is a real asset. Wexler, Ashcroft or Trerice are among other good names.

    Also you should check to see if the house will heat at an even lower pressure than you are using (unconfirmed/uncalibrated by a gauge, granted, until you replace it).
  • Cast Iron
    Cast Iron Member Posts: 35

    I don't think the system will build pressure until the generation of steam exceeds the condensing capacity of the system (all the rads get maximally hot all the way across) At least I notice this my one pipe steam system. Instead of 68* try driving the temp to 75. This will give the rads adequate time to heat all the way across. Perhaps the pressutrol will cut out then. By they way, my gauge does move to indicate pressure, but with a 30lb scale, you'll only see the needle move about a quarter of an inch before it pressurtrol cuts out at 1.5lbs.
  • Dave_12
    Dave_12 Member Posts: 77

    If you removed the pressure gauge, with the boiler on, steaming, and had no steam venting, I would say that the piping may be plugged. The most common place is where the piping enters the boiler, or possibly at the bottom of the copper siphon.

    The water condensing in the bottom of the siphon loop keeps live steam from the pressuretrol and pressure gauge to protect them. This water should quickly "blow out" when the boiler is making even a fraction of a PSI, when the pressure gauge or pressuretrol is removed.

    Good luck finding the problem. Check for plugging immediately as this is a safety concern.
  • J.D.Sarick
    J.D.Sarick Member Posts: 13

    Well, the local professional told me "if the system is working. . .don't fix what ain't broke." This after finding no steam traps in the radiators, no main vents, no F&T traps, and a wet return clean out valve that was spitting what looked like tar.
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