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BASEBOARD BLEEDING

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GREENMAN
GREENMAN Member Posts: 25
IM BLEEDING A HOT WATER ONE PIPE SYSTEM BECAUSE IM NOT GETTING HEAT IN SOME OF THE BASEBOARDS BUT WHEN I TRY TO BLEED THE ONES WITH NO HEAT I CAN'T EVEN GET WATER OUT OF THEM CAN ANYONE TELL ME WHY

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  • STEVE PAUL_3
    STEVE PAUL_3 Member Posts: 126
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    pressure loss

    You have lost the system pressure. No pressure, no water. It is time to replace the pressure regulating valve. After a new fast fill valve has been installed, set the pressure to 3-5 pounds higher than what is required to reach the highest point of the system. Power purge air from the mains from the purge valves and bleed the radiation from the individual bleeder valves. Be certain to return the power purge lever to the normal position
  • JIMBO_2
    JIMBO_2 Member Posts: 127
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    Explain Power Purge

    Some readers might not know exactly what a Power Purge is and/or how to do it correctly.
  • STEVE PAUL_3
    STEVE PAUL_3 Member Posts: 126
    edited October 2010
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    POWER PURGE

    Jimbo,

    You are absolutely correct, if I used a term I should have explained it.

    Power purging is the elimination and removal of the majority of trapped air in a hydronic heating system at a significantly higher pressure than the normal setting of the pressure regulating valve (PRV). In the case of a fast fill valve, there is a lever on the valve, that when lifted to the upright position raises the pressure from the normal setting to a pressure much closer to the higher inlet side pressure. The purging valve set up consists of a boiler drain on the return side close to the boiler with a full flow shut-off-purge valve immediately downstream from it.

    To power purge: fill the system by means of the PRV set at the desired pressure setting. When the system is pressurized to the setting all flow will stop. At this point, close the purge valve and attach a hose to the boiler drain. I like to put the end of the hose in a bucket. I then open the boiler drain and lift the lever on the fast fill valve increasing the system pressure. Watch the pressure gauge and don't allow the pressure to reach 30 PSI or the pressure relief valve will open.  Water and air will begin to flow into the bucket. Continue to allow the water to flow until the trapped air is eliminated from the system. This will be when there are no longer any visable air bubbles showing in the bucket. Then return the lever to it's normal position. Continue to let the water run until the pressure gauge shows the system to be at the desired pressure. Close the boiler drain and open the purge valve. The system has now been power purged. The remainder of any residual air will be absorbed into the water and will be eliminated by the air vents and the air scrubber. Get paid and go home.  
  • GREENMAN
    GREENMAN Member Posts: 25
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    POWER PURGE

    THANKS FOR YOUR ADVISE I DID POWER PURGE THE SYSTEM JUST LIKE YOU SAID TO DO AND I HAD NO MORE BUBBLES IN THE BUCKET BUT STILL NO WATER IN THE BASE BOARD WHEN I TRY TO BLEED IT . LOOKING AT THE SYSTEM THIS IS A ONE PIPE SYSTEM WHICH CONSIST OF A ONE INCH MAIN WITH 3/4 BRANCHES TO THE BASE BOARDS I INSTALL ONE MONOFLOW TEE ON THE PROBLEM BASEBOARD BUT NOW I LOST HEAT IN DIFFERENT BASEBOARDS WOULD THIS BE BCAUSE I NEED TO INSTALL MONOFLOW TEES ON ALL THE BASEBOARDS RETURNS TO THE MAIN
  • Mark Eatherton
    Mark Eatherton Member Posts: 5,853
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    Power purging and 1 pipe HW systems...

    It has been my experience that attempting to power purge a one pipe system where the convectors are above the main is like chasing your tail. You get a lot of exercise, but no satisfaction,,,,



    The fact that you are unable to get ANY water out of the bleeder indicates to me that your bleeders are plugged. Make certain that the rubber seal that is usually under the cap of the bleeder has not gotten stuck to the top of the bleeder. If it has, that is why you are not seeing water.



    You need roughly 1/2 PSI per vertical foot of system elevation, plus 5 pounds of residual pressure at the top of the system. This will ensure that you should be able to see water at that point.



    One pipe convectors located above the main normally have only one diverter.venturi tee per convector, and usually, but not always, on the return side where the water is slightly denser. Remember, hot water is less dense and naturally wants to rise upwards, so there is just a need for a little "incentive" to get hot water to flow up.



    If the convector is below the main, you have to FORCE the hot water down, and it usually requires two incentivisers (venturi tees) to get the job done and overcome the propensity of gravity.



    Under the cover of the base board, if you can pull up on the baseboard so that the vent fitting is the apex, do so and then start bleeding. Bleeding is always done with the pump off, otherwise, you are chasing bubbles and your tail :-)



    So, to review, make sure you have adequate pressure in the system to see water at the location you are looking for it at.



    With the circulator OFF, raise the piping of the affected baseboard, and manually bleed any air trapped therein out.



    Return to normal operation and see if you have heat. If you do, you're done. If not, get back to us.



    ME

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  • Alan (California Radiant) Forbes
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    Bleeding

    And if it gets really difficult, there are two tricks that I learned to help purge air.



    1) Increase the pressure to 25 and even 30 psi to squeeze the air bubbles smaller and un-stick them.  They are more likely to move around when smaller and you've got a better chance to pick them up at your air vent. (Thank you, Dan Holohan)



    2) Put a little dishwashing detergent in the water.  This gets rid of water's surface tension and allows the air to move around easier. (Thank you Mark Eatherton).



    Both of these have saved me countless hours at the drain bucket.
    8.33 lbs./gal. x 60 min./hr. x 20°ΔT = 10,000 BTU's/hour

    Two btu per sq ft for degree difference for a slab
  • LarryC
    LarryC Member Posts: 331
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    How does one add Dawn to a closed system?

    Home owner here.

    How would I add a bit of Dawn to a closed system without using a pump?
  • Jean-David Beyer
    Jean-David Beyer Member Posts: 2,666
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    It probably depends on your system.

    My system did not require Dawn in it, but it did need a caulking gun full of Sentinel X-100 to be added. X-100 comes in many forms, but the caulking gun cartridge is what my maintenance company uses. A short plastic hose comes out of the cartridge with a small nozzle at the end. For my system it would have been easier if there was a fitting like on a boiler drain valve. We isolated my house from the boiler and also the indirect from the boiler, opened the boiler drain valve, and tried to shoot the stuff into an open purge valve. But it went in too slowly. So the technician took the top of the purge valve out of the main valve body, and just squirt the stuff in. Worked out very well. He put the valve back together, closed the boiler drain valve, and restored the supply water. Air eliminator hissed for a little while to replace about 3 quarts of water. We started the system and I could hear a little air for a while.



    For my system, it is important that the air eliminator remove dissolved air because there is no air bleed in the upstairs zone, so if too much air gets up there, I have to purge that zone, and I would not care to do that. When they were putting in the baseboard, I asked why no bleed valves and they said baseboard does not require them. That is part of the reason I have a new heating company now.
  • GREENMAN
    GREENMAN Member Posts: 25
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    BASEBOARD BLEEDING

    FOUND THE PROBLEM THIS IS A ONE PIPE SYSTEM WITH NO MONOFLOW TEES

    THANK YOU ALL FOR YOUR HELP
  • Jean-David Beyer
    Jean-David Beyer Member Posts: 2,666
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    Out of curiousity,

    what was the problem you found?
  • GREENMAN
    GREENMAN Member Posts: 25
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    BASEBOARD BLEEDING

    THE SYSTEM IS A ONE PIPE SYSTEM SO IT HAS TO TO HAVE MONOFLOW TEES THE PERSON THAT INSTALL IT DID NOT USE MONOFLOW TEES AND THAT WAS THE PROBLEM.
  • Mark Eatherton
    Mark Eatherton Member Posts: 5,853
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    More than one way to venturi...

    including the venturi fitting made by Nibco. Like this http://img.directindustry.com/pdf/repository_di/12637/copper-fitting-catalog-123275_21b.jpg





    In addition to this fitting, there is also something called a scoop fitting. As the name describes, it is shaped like a scoop, and diverts flow accordingly. Like this http://www.accentshopping.com/ImageGen.ashx?IMG_ID=9654&IMG_Height=250&IMG_Width=250



    Just because it doesn't look like an official Mono-Flo tee, doesn't mean it can't make a difference. Had to be SOMTHING in there to cause the system to work.... Gravity?



    Air will stop water in its tracks. But you can usually hear that. Sounds like your belly after a bad breakfast burrito ;-( Gurgle.... gurgle gurgle.....SQUISH..... Gurgle.



    In order for there to be a difference, you must make a difference.... Thanks Gil :-)



    ME

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