Arkansas Water Furnance Low Loop Pressure

Discussion in 'Maintenance and Troubleshooting' started by wfopete, May 26, 2017.

  1. wfopete

    wfopete New Member

    I had a Water Furnace "E" series unit installed back in 2005. This was in a house that had no HVAC so everything was new. Installer subbed wells, they use a vertical closed loop system. I've heard some horror stories of Water Furnace "E" series units, are they considered a poor performer or problematic? Of course you never hear about the ones without problems!

    Anyway the problem is I started hearing a intermittent "gurgling" sound from the lines going into my unit when the A/C was on. The noise occurs after the unit is cooling for 15 minutes or more but it is intermittent. Yesterday I didn't hear it at all. The outside ambient temp might have something to do with that; I dunno.

    Had tech come out and the "In" water line was checked with 2psi noted. The assessment was a leak somewhere in the loop system and my "Choices" are to add/pump more fluid to the lines or replace the buried lines. I'm just a basic home owner but I'm trying to get smart on this system and how it operates.I'd like to get a more knowledgeable about diagnosing issues myself. Are there any other possibilities for this condition? If more fluid is required what type of fluid should I use?

    I found this on youtube and thought it was interesting:



    In 2009 the unit would not cool due to a leaking e-coil. That set me back $1200. Today I opened up the panels and found a large adjustable wrench wedged between the E coil and a piece of tubing (yeah, the $1200 coil repair). The wrench is bracing the tubing/fins of the coil. Sweet eh? I'm afraid to move it as it may cause a leak or it may be holding the coil in place. This repair was done by one of the "Best in the Biz" for Geo Thermal in the state :rolleyes:

    [​IMG]
     
  2. arkie6

    arkie6 Active Member Forum Leader

    Hey Pete! I remember you from some past River Valley Dirt Riders meetings and rides. I worked with Davenport before he retired. I'm guessing your installer's name rhymes with mood?

    Anyway, have you had to add any water to your loops since 2005? If not, any leak you may have is likely pretty tiny and wouldn't justify repair or replacement of the outdoor loop. I assume that you have a pressurized loop flow center somewhere near your geothermal unit? Have you verified no water leaks at the flow center or at any of the water connections on/in the geo unit? Have you ever monitored the entering and leaving water temperature on your unit during the winter? If it never drops below 45 degrees F or so, just straight clean water is all that is needed to replenish your loop. That is all that I use in my vertical loops and I'm only ~20 miles south of you. Is your loop header inside the home with individual loop isolation valves or is the header buried outside? That gurgling is likely air or voids and may need to be flushed out with a high flow flush cart, especially if the header is outside so that you have to flush all loops simultaneously.

    Another option is to install a non-pressurized flow center, but that will likely set you back approximately $750 (single pump) to $900 (2 pumps) in parts alone, but much cheaper than digging up your loops.

    Alan
     
    Last edited: May 27, 2017
  3. docjenser

    docjenser Well-Known Member Industry Professional Forum Leader

    Your gurgling is air in the fluid. You unlikely have a leak, and if only a small leak, since the air bubbles are simply gases which participate out of the water, and are now compressible. Once you put heat into the ground in A/C mode, the pipe expands more than the fluid inside, thus the fluid depressurizes, which causes gases dissolved in the water to participate out. This is when non pressurized flow centers come in, which avoid pressure fluctuations, and also purge out micro bubbles automatically.

    The are called the "call back eliminators" since one does not have to run out there again to purge out the loops. It sounds like you would benefit from having one installed.
     
  4. wfopete

    wfopete New Member

    Alan, You are correct Sir. This is the first problem since 2005 when the coil was replaced. I checked the unit and the lines going to it with no indication of leaks so that's the issue(s) in figuring out the location of the problem or mini leak. I'm not aware of any valving outside. AFAIK everything but the lines is inside. The techs that came out discussed the flush cart and said it would be a mess to do that inside the house. Fortunatley the lines come into my house through the crawl space where thet "could" tap into for adding fluid. I am not hip enough on the componets of a geo system to tell where loop flow center are located...yet. But I am interested in understanding the how and why the system works the way it does and how I can improve on what I already have.
     
    Last edited: May 26, 2017
  5. docjenser

    docjenser Well-Known Member Industry Professional Forum Leader

    Where is your heat pump located? Usually the flow center is close by and has the circulation pump(s) attached. One should be able to purge things from there, if everything is in your basement. Describe things a bit, maybe some pics would help. And take a picture of your nameplate which would give us info about the size etc.
     
  6. arkie6

    arkie6 Active Member Forum Leader

    Pete, if you have Pressure-Temperature (PT) ports (also coincidentally called "Pete" ports) installed at the geothermal unit water inlet and outlet (most units do have these), then you can buy or build a tool to re-pressurize your system to ~30 psi using a garden hose. This may be sufficient to eliminate the gurgling as the increased pressure may cause the gases to go back into solution.

    Note that a PT port is typically installed in a brass elbow right at the water inlet and outlet. PT ports typically have a knurled brass cap that you unscrew and inside will be a rubber valve with a split that allows you to insert a needle similar to a needle used to air up a football or basketball.

    Here is an example of a geothermal fill valve/needle/gauge on ebay: http://www.ebay.com/itm/GEOTHERMAL-...812177?hash=item3ae3bb6491:g:o18AAOSwJQdXC7~h

    If that link doesn't work, just search google images for [geothermal pt port needle]
     
  7. arkie6

    arkie6 Active Member Forum Leader

    Also, if your geothermal PT ports are at or near the high point of the loop lines, you may be able to rig up something using the fill valve/gauge/needle and some extension hose routed up high with another valve at the end to allow you to purge any air in your loops. Just leave the fill valve assembly inserted with the fill valve open and the valve at the end of the extension hose closed. Allow the system to run in this configuration for some time and you may get the air to accumulate in the extension hose routed to above the highest point in the system. Shut the fill valve and verify adequate system pressure. Add more water if needed. Better yet, use clear tygon tubing for your extension hose and pre-fill it with water before connecting to your geothermal unit. Now, if air migrates into the extension hose you can see it at the top of the hose and the water in the hose will displace the air in the loop lines.
     
    Last edited: May 27, 2017
  8. wfopete

    wfopete New Member

    Ok let's have a look at the beast. No basement and the unit is inside on the ground floor (single story house). The Flow Center is on the left (I could tell because the tag said "flow center"). The lines on the right go to my Marathon water heater.

    [​IMG]

    A better picture.

    [​IMG]

    Some info, hope you can read it.

    [​IMG]
     
    Last edited: May 27, 2017
  9. docjenser

    docjenser Well-Known Member Industry Professional Forum Leader

    You got everything there. Not sure why the techs said it would be a mess.

    You have a 2 ton unit with P/T ports at the end of the hoses (the brass caps on the brass squares) and a flow center with purge ports. You can definitely re-pressurize your system simple with a garden hose connected to a needle in the p/t ports, but I question wether you can get the air back in solution.

    But those are just rubber hoses with some clamps. You can do many things to get the air out, just as Alan describes it.
     
  10. wfopete

    wfopete New Member

    Sorry, I meant the lines on the RIGHT go to my water heater. I fixed it.
     
  11. arkie6

    arkie6 Active Member Forum Leader

    Pete,

    If you have trouble getting the air out of your lines, you might consider putting a "T" and valve at the high point of those rubber hoses between the flow center and the geothermal unit with the "T" and valve pointing up. With the unit shutdown, air should migrate to this high point and you can crack open the valve connected to the "T" to allow the air to escape and then re-pressurize the loop via the PT ports.

    You can probably find a 1" barb x 3/4" male pipe thread "T" to insert in those rubber hoses at Leonard's Hardware. Then screw a 3/4" PVC ball valve onto the 3/4" male threaded portion of the "T". If you can't find a suitable "T" at Leonard's, this link has a brass T that should work: https://keithspecialty.com/water-line-insert-brass.htm

    I know for sure that Leonard's or Lowes will have a 3/4" female pipe thread PVC ball valve but here is the link to the PVC ball valves from the above site: https://keithspecialty.com/k/pvc-plastic-ball-valves-threaded.htm

    Alan
     
  12. wfopete

    wfopete New Member

    Alan, I think you and I need to have conversation over a couple CJ's burgers real soon.

    I'll buy (something that doesn't happen very often)! :D
     
  13. arkie6

    arkie6 Active Member Forum Leader

    Pete, that sounds good, but right now I'm working 12-13 hours per day during the ANO outage.
     
  14. wfopete

    wfopete New Member

    Ya' gotta eat sometime!
     
  15. wfopete

    wfopete New Member

    Back on topic with an update. I have not heard any noise of the gurgling from the unit since the two instances noted in the original post. Is this typical? I know the unit still has pressure issues but the noise seems to have ceased...for now.
     
  16. docjenser

    docjenser Well-Known Member Industry Professional Forum Leader

    It likely has pumped the air bubbles back to the loop field.....
     

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