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Steam Boiler Pressure

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helpineed
helpineed Member Posts: 35
in Strictly Steam
Should pressure remain in the boiler after it is shut down ? I have noticed 7psi on the gauge constantly, while the boiler is on or off. I intend to check for a clogged syphon/pigtail as the boiler does not cycle on or off, it just keeps burning once started up,
How do i release the pressure safely to remove syphon/pigtail & pressuretrol ?

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  • MilanD
    MilanD Member Posts: 1,160
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    Gauge is probably broken. How old is your boiler?

    Once steam boiler is off and cold, if it's not a vacuum 2 piper between cycles, it should go to atmospheric. Why gauge broke needs to be investigated. Was there originally a high operating pressure?

    Check as you intended for clogged pig tail, but once you fire it up, check pressuretrols/vaporstat didn't go bad... Good time to add low pressure gauge, and also replace the prv, just in case. Op pressure in excess of 15 psi should have triggered the prv. You shouldn't come to that pressure of course, but did you and how would you know if you did?

    If psi goes above 15 and prv does not engage, that is extremely dangerous. Then again, your rads vents would probably be hissing like crazy before the system would climb anywhere close to 15, and that too would point to other problems with the system like enormously oversized boiler, bad piping, etc. Does your system hiss like that? If 2 pipe, does your main vent his loudly?

    So if old, gauge may have gone bad, just investigate under what circumstances this would have happened.
  • Grallert
    Grallert Member Posts: 644
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    The pressure will drop a short time after the burner shuts down and the steam condenses. Really the only thing keeping you from servicing the pigtail is the temperature of the parts not the pressure in the system. Give everything enough time to cool off a bit.
    Miss Hall's School service mechanic, greenhouse manager,teacher and dog walker
  • helpineed
    helpineed Member Posts: 35
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    The pressuretrol settings are 4psi + 3 on the wheel. The boiler will not come on with the settings lower than that. Which is why i'm going to check out the pigtail. this is my first winter in this house also first time messing with steam heating and heating bills are out of this world ALREADY!!
    I'm looking to purchase a new pigtail and the associated fittings to replace instead of cleaning.
  • helpineed
    helpineed Member Posts: 35
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    Boiler has been off since 6am this morning and is cold to the touch.
  • Koan
    Koan Member Posts: 439
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    +1 for pigtail and gauge replacement. Don't forget to fill it with water.supplyhouse.com/Generic-PIGTBRA-1-4-Angle-Brass-Pigtail
  • Koan
    Koan Member Posts: 439
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    seems like a very high pressure as well?
  • helpineed
    helpineed Member Posts: 35
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    Koan said:

    +1 for pigtail and gauge replacement. Don't forget to fill it with water.supplyhouse.com/Generic-PIGTBRA-1-4-Angle-Brass-Pigtail

    Is it that I fill up the pigtail with water ? I was not aware!
  • KC_Jones
    KC_Jones Member Posts: 5,739
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    The pigtail should have some water in the bottom part of the loop, not necessarily full of water. It's to isolate the gauge and pressutrol from the steam to prevent damage.
    2014 Weil Mclain EG-40
    EcoSteam ES-20 Advanced Boiler Control
    Boiler pictures updated 2/21/15
    helpineed
  • JUGHNE
    JUGHNE Member Posts: 11,062
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    I would go with an new 0-5PSI gauge. If you run over 5 PSI you have other issues.
    Also adjust the control as low as possible for the cut-in, and the inside white wheel at 1 for cutout. See what that does for you.
    If the fire short cycles you need to report back.

    After removing the old pigtail, be sure the hole is open into the boiler.
    You can very slowly pour water into the pigtail until you hear water running into the boiler water, then you know the lower loop in low.

    In the future you can just remove the gauge and blow into the pigtail to insure it is clear, then refill with water before reinstalling the gauge.
    MilanDethicalpaul
  • helpineed
    helpineed Member Posts: 35
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    UPDATE!!
    I was able to remove the pigtail last evening to inspect it. Just as suspected, it was about 95% blocked up, I even saw some crud at the bottom of the gauge!
    I cleaned up everything ( my son was suggested coca cola, but i used carb & choke cleaner) and put back the assembly on the boiler. (I neglected to order the new stuff last week, but did so last night)
    The pressuretrol was adjusted to 1 psi + 1 on the wheel. The boiler was fired up and it cycled well. When I woke up there were no cold areas in the house (except for the one room where the radiator refuses to work. This is my next project!). Previously the boiler just ran nonstop. So it was uncomfortably hot in some rooms, but there's more balance in the system now. I did not go to 0.5 psi because previously the boiler would not run on anything less than 4 psi + 3 on the wheel.
    The pressure gauge does not show a reading, I have ordered a new low pressure gauge also. The heat is off now. I have already adjusted down to 0.5 psi so when next it is turned on i will monitor the outcome.
    I came to this group for answers and you guys have been awesome. With your help I was able achieve more results than the so called professional that came. I feel as if i'm in a different house!
    MilanDethicalpaul
  • jtompkins
    jtompkins Member Posts: 12
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    How did it work going to .5psi + 1?

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