Discussion in 'Maintenance and Troubleshooting' started by wmdgeo, Feb 19, 2010.

  1. Mark Custis

    Mark Custis Not soon. Industry Professional Forum Leader

    Thanks to Phil, Dewayne and Curt

    This might be something to etch in stone.

    I now have time lines and pressures to guild my testing of my Rube Goldberg installations.

    Yours in dirt,

  2. Ed9395

    Ed9395 New Member

    I have been having simular issues with mine.
    When I had it installed, I did manage to have one end of the six ground loops installed in the house. Sure wish both ends would have been done that way.

    The picture looks like a pretty clean retro.
    Are those PVC shut off valves on the black poly? What did you use to plumb them in?

    Hoping I don't have to go to that extreem to fix our system.


  3. wmdgeo

    wmdgeo Member


    After trying to solve FP1 all last winter, I think we came up with a solution and the system was working like a charm, until last night when we were getting pounded with wind gusts and a -15 wind chill. The system locked out. The good news is that it was not an FP1, but an LP/LOC fault 3. So I got the system reset, and running, and it locked out again today. It is not leaking refrigerant. I changed the air filter which was probably dirtier than it should have been. Still locking out however. Please point me in the right direction soon. I can't deal with this again all winter !
  4. Ed9395

    Ed9395 New Member


    Enough time has passed that I can't recall what the fault codes mean without consulting my manuals.I can tell you though what was done, and I haven't had a problem with it since.

    While waiting for the service people to return with their flush cart, I managed to order a new control card, and both thyristers. Finally the service people got the correct couplers to flush my ground loop, and came to my place to do that.

    They decided to replace the thyristers and flushed the ground loop. There was obviously some air flushed out of the ground loop and afterit was pressurised and the system started right up. They retested the temp/ pressures.

    For me it was a frustrating ordeal, that took a month to resolve. Good thing it wasn't in the high heat part of the season.

    Good luck with yours,

    Hope you post a reply, I am curious what your first solution was.

  5. wmdgeo

    wmdgeo Member


    I have attempted to "shock" the system by switching to AC mode for several minutes, and then back to heat. The system will pump heat for a couple of minutes (maybe 10) and then blow cold air. The transport lines form the manifold to the flow center and from the flow center to the unit are warm - as if the system is not extracting heat from the fluid. Prior to the lockout last night the line would be cool to cold and condensated. Does this description indicate anything that would be consistent with LP/LOC Fault 3 ?

    Coil was dusty ... we cleaned it.
  6. Mark Custis

    Mark Custis Not soon. Industry Professional Forum Leader

    I am cutting through western MD

    on our way to DC for Christmas.

    Well I am determined to get this system fixed.

    Lets review.

    Last winter the issue was an FP1 or code 4 (4 flash led read out after shorting the test pins) lock out. The board locks out because it "sees" low temperature in the loop side co-ax heat exchanger. The authors of the manual for the CXM control in REV. # 4, dated June 2010 finally admite to see the low water temperature they look at refrigerant temps not water temps.

    How did that get resoved?

    Now we are getting a code 3 lock out which, (in the same revision of the CXM I/O manual) says the control is seeing and open low presure switch for thirty continous seconds before or durring a call after ignoring the fist 120 seconds after the call.

    The low pressure switch is located at a point in the refrigeration circuit that is on the low side of the compressor in both heating and cooling. I see two things that could cause the fault; low pressure or a bad switch, (open circuit).

    Reversing the flow of refrigerant will not effect the code 3 lock out. Sounds like you have a refrigerant leak, or a bad switch. A dirty coil or plugged filters would cause a code 2 or high pressure fault in heating mode.

    Is this unit R-22 or is it R-410A? A 410A system will have pink stickers on the compressor. I'll Load both on the motor home.

  7. engineer

    engineer Well-Known Member Industry Professional Forum Leader

    Sounds right to me

    FWIW WF monitors refrigerant temp leaving the Coax for the purpose of its "low water flow" lockout.
  8. wmdgeo

    wmdgeo Member

    We fixed FP1 ultimately by reconfiguring the manifold using the radiant flooring mainfolds. I believe that we were getting airlocks prior to the reconfiguration because the original setup did not allow each loop to be flushed individually, therefore the flushes were not thurough. Also had to clip JW3.

    My service man suspects that we do truly have a loss of refrigerant charge in the current situation. He disconnected the CXM to see if we could successfully pump heat without a sensor tripping the fault, and we cannot. The compressor is not pumping heat. It is blowing cool air, and the transport lines are warm, not cool to cold as they should be if the heat is being extracted. Hopefully we can get this system working soon. Any more thoughts would be appreciated. Thanks for your advice Mark.
  9. wmdgeo

    wmdgeo Member


    Are you suggesting the compressor needs replaced ???
  10. Mark Custis

    Mark Custis Not soon. Industry Professional Forum Leader

    Boots on the job site know best

    No. If the compresssor, I assume it is a scroll, no valves, was not working there would be no Code 3 low refrigerant presure lock out. If it is a recipricol compressor the same hold true, no pumping, no lock our. The last thing I do is get out my manifold guages to check the refrigerant charge in any system.

    It is time to check the charge in this unit. Being a reformed RTU hack, the reformation comes from not having the body left to get to the roof, I think the time is now to add guages and see where the PSIG numbers are on this unit. Adding the guages which will lessen the refrigerant charge by deffinition requires real acurate numbers at other parts of the system to have any meaning.

    I would like to know what is in this system and it's date of manufacture.
  11. wmdgeo

    wmdgeo Member

    I think (HOPE!) it's fixed

    My service guy checked the refrigerant charge, and it was 10 oz short from required specs. So he added 10 oz. to top it off at 54 oz of refrigerant. It has since been pumping heat. Since it was not leaking, he says that perhaps he neglected to recharge it to the full 54 oz we he was doing every test in the the book to fix the first problem last winter. Whatever - just as long as it's the solution and it works moving forward it is fine with me. I presume it makes since then that we had a LOC fault.

    While i'm posting, is it unusual for a unit to run for very LONG (hours) cycles when the outside temp is extreme cold (< 10 F)? Does this set the system up for a lockout when it gets pushed this hard ? I guess I am just a little paranoid from all the lost sleep from last winter's FP1 issues. THANKS !
  12. wmdgeo

    wmdgeo Member

    spoke too soon

    Well, I spoke to soon. Now I just got an FP1. Here is what I notice. The first half of the incoming hose from the circulating box to the unit is warm. It is not typically like this when it is working properly ... rather, it is cool to cold. Does this tell us anything ?
  13. Mark Custis

    Mark Custis Not soon. Industry Professional Forum Leader

    You could have lost a pump

    Do you have any tools or electric meters?
  14. wmdgeo

    wmdgeo Member

    No HVAC tools ... Give me some ideas to throw at my local service guy. It is real cold here and it is running hard to maintain temp.
  15. Mark Custis

    Mark Custis Not soon. Industry Professional Forum Leader

    With out good numbers...

    ...on all points in the system it is impossible to know that the refrigeration side of this machine was "down ten onces". I use that much gas adding my manifold gauge set to a machine. The ONLY way to be able to prove that statement is to "weigh out, evacuate, and weigh in"' a charge. Hence the magic of compounds that "change state" and the engineers, (sorry Curt) that design them to enable squeezing 40*F to 130*F and give us heat pumps. My hat is off to them and their techs that turn the math into reality.

    With out listening to the tech, or reading his report, I can not tell if he is right or should be shot.

    I do know that It is possible that all your trouble with this system could be a bad heat exchanger. I can not tell from what your tech is telling you and then you telling me if that idea is true or possible

    I own two coaxial heat exchangers for my own errors in measurement or judgement. One each 4 tons and 3 tons, new and still in the origianal box. (I miss my spell check).

    The numbers and issues you report here do not add up. I will wave as I pass your problem going and coming from inside the beltway.

    Good luck,
  16. engineer

    engineer Well-Known Member Industry Professional Forum Leader

    One can learn a bit about a system's refrigerant situation by connecting only the low side gauge, the side to which charge is added anyway. Disconnecting the gauge with the system running ensures a minimum loss of refrigerant - just a bit of vapor.
  17. Mark Custis

    Mark Custis Not soon. Industry Professional Forum Leader

    I run with the

    Red hoses in the truck. saves temptaion and refrigerant.


  18. teetech

    teetech Member Forum Leader

    Tells me you should put the refrigerant gauges away and flush the loop.
  19. wmdgeo

    wmdgeo Member

    2 questions

    1) If there was a pinhole in one of the loops, could it open up to a larger hole in the winter as the cold loop fluid circulates causing the loop pipe to contract ? The symptoms seem to be pointing to air in the loop, however we pressure tested the loops on 8/31, and they held air as follows:

    Results: 11 AM 50.5 PSI, 12 PM: 48.5, 1PM: 48, 2PM: 47.5, 3PM: 47.5, 4PM: 47, 5PM:47, 6PM: 46.5; 8/28: 45 PSI

    We also sprayed down all the fittings which rendered no air leakage.The well driller said that the 5 PSI drop was acceptable due to "creep" and change in loop temperature beneath the surface of the Earth.

    We are going to flush each of the 4 loops independently to see if there is evidence of air. Am I correct that air in the loop will render bubbles in the flush cart ?

    2.) Is it possible that the parameters on a geo system could be correct, and still yield an FP1 lockout if it runs for hours on end simply because the system has extracted much heat and dropped the EWT to the 10F limit ?
  20. wmdgeo

    wmdgeo Member

    EUREKA !

    Well i hope I don't jinx myself like last night, however I believe that I found the source of the FP1 fault, and it is consistent with what my service guy and teetech suggested. The plug on the left side of the flow center has fluid leaking out of it like water dripping from a rain spout after a light rain. Seems like a good source of air leak to me. Inline pressure gauge also dropped to 0. So my question is What could have caused this ? We have not opened the flow center to flush the loops since 8/31, and it worked great until the LOC on Monday and the FP1 last night. We are replacing the flow center.

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