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Please Help - Losing My Mind (Purging Air)

smithsfan
smithsfan Member Posts: 12
edited August 2022 in THE MAIN WALL
I've got a brand new system, I've designed and built. I made it so every thing is simple, especially to isolate and purge air. Last night I'm trying to purge air out of a single upstairs fin tube zone.
Pumping through the circulator pump into the zone and out the return. I'm purging with a transfer pump and cycling the same water so I can watch the bubbles. For an hour now I'm still get big gulps of air pissing out that hose and for the life of me can not figure out how there can still be air trapped in this zone.
Single story house, 1400 square feet. Zone probably only has 50 or so ft of baseboard on it. I'm losing my mind because I designed the system to make purging easy!

At first I was purging the zone without having filled the primar, so I was maybe thinking the iso-flange was leaking by and pulling air in, but I filled both primary loop and circuit so that's now not possible and I'm still getting air. Any ideas at all??? Pic attached. Lastly (stupid question) But baseboard is bi-directional correct? When I tied in my new system to the old I used the return pipe as my supply and and VS/Versa for the return because it was easier to pipe.

Comments

  • STEVEusaPA
    STEVEusaPA Member Posts: 5,977
    Why do you need a pump? Don't you have a boiler feed? How are you able to maintain the proper pressure?
    You should be able to bleed from the boiler feed, thru the zone, and all the way back to the boiler drain, or at least out each zone.
    Are you sure those webstone valves are oriented in the right direction? Usually the purge is on the outlet of the circulator.
    steve
    EdTheHeaterMankcopp
  • smithsfan
    smithsfan Member Posts: 12

    Why do you need a pump? Don't you have a boiler feed? How are you able to maintain the proper pressure?
    You should be able to bleed from the boiler feed, thru the zone, and all the way back to the boiler drain, or at least out each zone.
    Are you sure those webstone valves are oriented in the right direction? Usually the purge is on the outlet of the circulator.

    I haven't piped in the boiler feed yet, I will at some point. Those webstones are 3 ways, and I'm pumping through the pump and out the return for that circuit. Is there an issue pumping through the pump? I know those webstones are usually on top, i figured it didn't really matter.
  • EdTheHeaterMan
    EdTheHeaterMan Member Posts: 4,972
    edited August 2022
    It's all about velocity. and if you are not moving the water thru the second floor fast enough to entrain the air as it is flowing down the vertical pipes, then some of that air will continually be trying to float to the top of the "Down" pipe as the water is flowing down. Higher water pressure from your fill valve will help.

    When ever I purge a second or third floor loop, I try to get the expansion tank filled with as much water pressure as I can before I open the purge valve. Then once the tank is filled, with the fill valve open and still building pressure, I open the purge valve and watch the water and air flow out at high velocity. Both the water from the fill valve and the water from the expansion tank will be flowing down that vertical pipe for a few seconds at an accelerated rate. I may do this 3 or 4 times on some really high loops until I'm sure that there is as little air left as possible.

    As long as you get some circulation of heat thru that loop, and you have your air elimination system properly designed, then you just operate the boiler and let Boyle's Law and Henry's Law do their job to eliminate the remainder of the air from the system. For more info on this read Pumping Away, available from the store on this website or at Amazon.com (you know the online book store that would never work)

    SO GET YOUR FEED PIPING DONE SOONER THAN LATER.

    Hope this helps.
    Mr.Ed
    Edward Young Retired HVAC Contractor & HYDRONICIAN Services first oil burner at age 16 P/T trainer for EH-CC.org
  • EdTheHeaterMan
    EdTheHeaterMan Member Posts: 4,972
    edited August 2022
    In your discussion title: "LOOSING MY MIND"... This is not the best place to look for it. Most of us here have already lost our minds. Look at the business we chose to work in! No sane person would choose this!

    Those that agree will LOL this post
    Edward Young Retired HVAC Contractor & HYDRONICIAN Services first oil burner at age 16 P/T trainer for EH-CC.org
    IronmanMikeAmannHomerJSmithZman
  • smithsfan
    smithsfan Member Posts: 12

    It's all about velocity. and if you are not moving the water thru the second floor fast enough to entrain the air as it is flowing down the vertical pipes, then some of that air will continually be trying to float to the top of the "Down" pipe as the water is flowing down. Higher water pressure from your fill valve will help.

    When ever I purge a second or third floor loop, I try to get the expansion tank filled with as much water pressure as I can before I open the purge valve. Then once the tank is filled, with the fill valve open and still building pressure, I open the purge valve and watch the water and air flow out at high velocity. Both the water from the fill valve and the water from the expansion tank will be flowing down that vertical pipe for a few seconds at an accelerated rate. I may do this 3 or 4 times on some really high loops until I'm sure that there is as little air left as possible.

    As long as you get some circulation of heat thru that loop, and you have your air elimination system properly designed, then you just operate the boiler and let Boyle's Law and Henry's Law do their job to eliminate the remainder of the air from the system. For more info on this read Pumping Away, available from the store on this website or at Amazon.com (you know the online book store that would never work)

    SO GET YOUR FEED PIPING DONE SOONER THAN LATER.

    Hope this helps.
    Mr.Ed

    The issue. I'm bypassing the primary loop, water makeup, expansion tank etc.. by pumping from a water bucket directly into the zone with the primary supply and primary return isolated from the purging.

    Is this not also an effect way to purge the zone of air VS dumping water in through the makeup system, through the primary and through to the zone being purged?
  • hot_rod
    hot_rod Member Posts: 18,222
    edited August 2022
    Make sure the Webstone are flowing  properly. The new ones purge from either direction depending on how you install the handle. Simple enough to flip the handle and confirm

    If you purge into the same bucket you can pump some air that you purged. Why not just hook a garden hose from you home water pressure? Keep the pressure under 30 psi if you are going through the boiler
    Bob "hot rod" Rohr
    trainer for Caleffi NA
    Living the hydronic dream
    STEVEusaPA
  • EdTheHeaterMan
    EdTheHeaterMan Member Posts: 4,972
    edited August 2022
    What is the velocity of the water that the pump can pump? It is a good way to purge any system as long as there is enough velocity to entrain the air on the way DOWN.

    It is not a good way to purge if the pump does hot have enough force to make the air entrain in the water flow on the way DOWN.

    You must remember that air is much lighter than water. Air will always want to go to the top of a water column.

    Think of it like this. Air is so buoyant that it will climb to the top of the column of water at about 60 feet per minute. If the water flowing down the pipe is only going 30 feet per minute, then the air will win the race up the pipe. If the water going down the pipe is flowing at 90 feet per minute, then the water will win and the air will be pushed out.

    To paraphrase Sheriff Brody "I think your going to need a bigger PUMP"
    Edward Young Retired HVAC Contractor & HYDRONICIAN Services first oil burner at age 16 P/T trainer for EH-CC.org
  • hot_rod
    hot_rod Member Posts: 18,222
    Looks like a 1/2 hp Liberty knock off. You may have too much pump churning up the water, try flowing down the flow with the valve, A 1/2 hp will do a 6-8 port manifold with all loops open 

    what do you have to lose 
    Bob "hot rod" Rohr
    trainer for Caleffi NA
    Living the hydronic dream
  • jumper
    jumper Member Posts: 1,911
    Air pump at high point saves time. Also filling with degassed water.
  • mattmia2
    mattmia2 Member Posts: 7,190
    Those hoses are tiny, with that reduction you probably aren't getting enough flow to get the air out. Try a garden hose hooked up to a laundry tray or something like that.
  • pedmec
    pedmec Member Posts: 713
    So your pumping the water that your purging back into the loop and you can't figure out why the loop keeps getting air bound. How about you keep pumping the same air entrained water back into the loop. That's why you can't get the air out. your pumping it back in. That's exactly how not to purge a water based heating loop
    Hook up your water feed like your suppose to and then purge it. and don't worry about water down the drain. it doesn't cast that much.
  • EdTheHeaterMan
    EdTheHeaterMan Member Posts: 4,972
    pedmec said:

    So your pumping the water that your purging back into the loop and you can't figure out why the loop keeps getting air bound. How about you keep pumping the same air entrained water back into the loop. That's why you can't get the air out. your pumping it back in. That's exactly how not to purge a water based heating loop
    Hook up your water feed like your suppose to and then purge it. and don't worry about water down the drain. it doesn't cast that much.

    I think you are not seeing the big picture. The pump is getting the water from a large bucket. As long as the hose connected to the inlet of the pump is at the bottom of the bucket, there should be no recirculation of air bubbles (of any large quantity anyway). That water is pumped into the loop and forcing out any air in the loop. any air that is returning to the bucket will probably not find its way to the bottom of the bucket. I'm not 100% sure on this point @pedmec but I think any air bubbles tend to rise to the top of that bucket and refrain from searching for the bottom of the bucket. I will need to do more research on this phenomenon of air bubbles in water and conduct some scientific experiments to verify this. I will update you with my findings shortly.

    If my hypothesis is correct, the pump will be pushing mostly water into the system. Air of the quantity that @smithfan is talking about is not from the bubbles recirculating as you propose.

    Edward Young Retired HVAC Contractor & HYDRONICIAN Services first oil burner at age 16 P/T trainer for EH-CC.org
    mattmia2DJD775
  • EdTheHeaterMan
    EdTheHeaterMan Member Posts: 4,972
    Research completed @pedmec

    Large Air Bubbles do float to the top of the bucket and leave the water rather quickly. Depending on the size of the bubble, the air rises to the top of the water at a rate of about 1 ft per second. Your actual bubble may vary.
    Edward Young Retired HVAC Contractor & HYDRONICIAN Services first oil burner at age 16 P/T trainer for EH-CC.org
  • hot_rod
    hot_rod Member Posts: 18,222
    Pull water from the bottom and have the purge hose at top pointing at the side of the bucket. That will help dearest’s the purge water. And keep the bucket filled as you purge

    unless you are pumping in glycol, just use a hose from a hose bib, no recirculated air to deal with, plenty of flow 

    An Autofill valve on fast fill works also.
    Bob "hot rod" Rohr
    trainer for Caleffi NA
    Living the hydronic dream
    EdTheHeaterMan
  • Zman
    Zman Member Posts: 7,434
    Have you tried rotating the isolation valve 180 degrees? https://www.nibco.com/brands/webstone/isolator/ You may be isolated from the heating loop.
    If you are just adding water, why bother with the pump? You can just hook up a high-pressure water hose and let-er-rip ;)
    "If you can't explain it simply, you don't understand it well enough"
    Albert Einstein
  • MikeAmann
    MikeAmann Member Posts: 683
    Zman said:

    If you are just adding water, why bother with the pump? You can just hook up a high-pressure water hose and let-er-rip ;)

    ^^^ What he said. ^^^

  • pedmec
    pedmec Member Posts: 713
    Couldn't disagree with you more ed. If that wasn't the case how come he still can't get the air out? wheres the air coming from? you act like there is no turbulence in the bucket and all the air is separating and to going to the top. If that was the case there would be no more air in the loop.
    The only other way is his hose connection is not tight on the suction side of the pump and its sucking air in. Either way its not the ideal set-up.
  • mattmia2
    mattmia2 Member Posts: 7,190
    pedmec said:

    Couldn't disagree with you more ed. If that wasn't the case how come he still can't get the air out? wheres the air coming from? you act like there is no turbulence in the bucket and all the air is separating and to going to the top. If that was the case there would be no more air in the loop.
    The only other way is his hose connection is not tight on the suction side of the pump and its sucking air in. Either way its not the ideal set-up.

    With those tiny hoses connected in to 3/4" pipe and that pump that is probably built more for flow than pressure there just isn't enough flow to entrain the air at the top of the loop and pull it down to the bucket. Replace those hoses with 3/4" id hoses and the air goes away.
  • hot_rod
    hot_rod Member Posts: 18,222
    Looks like 5/8 washer hoses which supply plenty of flow. Thats what most pump carts come with, 8 gpm with no problem and 3- 4 gpm should purge 3/4 zones. We upgraded the Caleffi carts to 3/4 hoses and get 10- 12 gpm with a 1/2hp pump.

    T Ball valves at the pump, I'd check the flow direction on the handle, it must be going the wrong direction somehow. That should purge inn 10 minutes or less the way is is connected.
    Bob "hot rod" Rohr
    trainer for Caleffi NA
    Living the hydronic dream
  • EdTheHeaterMan
    EdTheHeaterMan Member Posts: 4,972
    edited August 2022
    pedmec said:

    Couldn't disagree with you more ed. If that wasn't the case how come he still can't get the air out? wheres the air coming from? you act like there is no turbulence in the bucket and all the air is separating and to going to the top. If that was the case there would be no more air in the loop.
    The only other way is his hose connection is not tight on the suction side of the pump and its sucking air in. Either way its not the ideal set-up.

    Without knowing what the pipe size is on the path where the water is traveling down a vertical, I can only guess. However, if the second floor loop has all air, and the pump is lifting water up to the second floor without the help of the weight of the water going down the vertical, then the pump is using much of its head pressure lifting that water up to the second floor, If the speed of the water is not fast enough (since much of its energy is used getting up to the second floor) to entrain the air in the second floor loops, and there are some pipes between the radiators that drop below the floor and then rise back up to the radiator in the next room, and this happens several times, then I would guess that the air is coming from those air pockets in the ups and downs in the loop.

    As more and more air in those high spots find their way to the ultimate vertical drop to the basement, the weight of the water going down will help in reducing the head needed to get the water up there in the vertical pipe going UP. This will then increase the velocity of the water going down and reduce the amount of energy the pump is using to lift the water up the vertical. This help will stop as soon as there is more air than water in the vertical DOWN pipe. So then the water will slow down and build up in the horizontal ups and downs until there is another flush of water down the vertical taking another group of bubbles down with it. This may repeat over and over again until all the air is removed.

    But if the pump does not have the velocity to entrain all the air to overcome the head pressure needed to lift the water to the top and continue to have sufficient velocity to keep the air entrained until all the air is flushed out, then the cycle of a little burst of bubbles and then some water then bubbles then water and on and on will continue for some time. But I could be wrong. I believe that more water pressure will resolve the problem. Whether that pressure is from city water pressure, or well water pressure, or a pump with more water pressure. More pressure, volume and velocity will get the job done.

    But I could be wrong. Perhaps lower pressure and slower flow and less GPM would do the job. I leave it to the experts, I only have experience in using that type of pump and that type of hose in a bucket set up over my 40+ years of actual service work. My experience will not come close to the experts that wish to come up with any alternative to the more pressure more flow and more velocity idea. @pedmec is probably correct, @smithfan is not doing it correctly because the air coming out of the hose into the bucket will get sucked up like a magnet into the inlet of the pump. It is just common sense, @smithfan would never think of something so basic and fundamental as letting air get sucked in to the inlet of the pump.

    See what I mean @smithfan. This is the wrong place to come to find your mind. We have all lost our minds here. You will never find your lost mind here
    Edward Young Retired HVAC Contractor & HYDRONICIAN Services first oil burner at age 16 P/T trainer for EH-CC.org
    Larry Weingarten
  • GW
    GW Member Posts: 4,592
    That arrangement won’t work, need to change the valve orientation 
    Gary Wilson
    Wilson Services, Inc
    Northampton, MA
    [email protected]
  • hot_rod
    hot_rod Member Posts: 18,222
    It looks like a version of this 331 garden hose transfer pump. I've worn out two of these over the years. Maybe a Harbor Freight opr boc store version inn the post?

    Here is my purge bucket. A dozen washer hoses, a small water meter, and a Quicksetter flowmeter with hose connections.

    So I know how many gallons go into a system, at what flow rate for determining velocity if needed.

    I've used this arrangement on solar and hydronics for 30 or more years. I also purged a 1" 500' geo loop at my place with it. One loop at a time on a 4 loop pond GEO.

    Hound dog approved :)
    Bob "hot rod" Rohr
    trainer for Caleffi NA
    Living the hydronic dream
    Larry Weingarten