New York ClimateMaster TZ22: Systematic LT1 crash on stage 2

Discussion in 'Maintenance and Troubleshooting' started by llaforest, Dec 8, 2014.

  1. llaforest

    llaforest Member

    Hello, we have just installed a new 3ton ClimateMaster TZ22 in open loop.

    We are experiencing a new problem today:
    When the machine is started in Stage1, everything is fine. EWT around 47, LWT around 45, LT1 around 34.
    But as soon as stage 2 kicks in, LT1 is dropping to 26 in 1 minute and the machine crashes there with LT1.

    The valve is opened to 100% this is why delta T is 2F but it seems it has no effect because when the machine crashes, LWT has not dropped yet... It has been working a month so far and when Stage2 kicks in, it usually drops the LT1 of a couple of degrees but nothing drastic. Now it's going down very fast and we don't understand what the problem might be.

    If anyone has a clue about what we are experiencing, please le me know.

  2. AMI Contracting

    AMI Contracting A nice Van Morrison song Industry Professional Forum Leader

    You need to check the GPM. A large DT between entering and leaving water suggests insufficient water flow. If you have any sort of sediment filter that could be partially plugged.
  3. geoxne

    geoxne Active Member Forum Leader

    I assume low water flow and should be verified.

    I realize from previous posts that you have had issues in the past and have made some "tweaks" to the vFlow system. These may have upset the systems operating logic (some undocumented) and you might have to start from the beginning.

    This video might give some insights. Pay particular attention at 37 min 30 sec.
  4. llaforest

    llaforest Member

    Haha good catch about my previous experiments. :) This one is a new beast that was installed a month ago in another house.

    The flow is around 8GPM whit valve opened to 100%, first we thought that it might be frozen in the return but no...
    Since we have the error this morning, we operate in manual mode. So the flow is constant with valve to 100%. We start on stage 1 and every thing gets stable, all numbers are normal. As soon as we enable stage 2, the LT1 drops but only LT1, the rest of the sensors have not even the time to go down or up.

    A few hours of test later...

    After some more tests it seems that LT1 stabilizes lower than at the beginning a month back. We added a little heating near LT1 sensor and it stabilizes to what would be 25F... LWT is stable with delta of 2F... So far so good, it's just like the water coil heat transfer has changed in the first month. Now the numbers are matching those we have on our other Geo installed in the other house...

    So I suppose we are fine after all. We knew with water around 47F, the open loop system of ClimateMaster does not work well. It's just the first time this new machine needs a little LT1 kick :)

    Thanks for the support.
  5. llaforest

    llaforest Member


    We have been running for a while now and what seems to occur is that as time goes by, the difference between LT1 and compressor discharge seems to increase. Leaving air, leaving and entering water are all within normal ranges.

    Now LT1 is 22 and comp. discharge 210 approx on stage 2. I have the impression that they should move both in the same direction, both up or both down, but not go opposite like that. Is there an explication to what I see?

  6. AMI Contracting

    AMI Contracting A nice Van Morrison song Industry Professional Forum Leader

    Are you taking the measurements with the DSH on or off?
  7. llaforest

    llaforest Member

    DSH is on with water tank full at 145f.
  8. AMI Contracting

    AMI Contracting A nice Van Morrison song Industry Professional Forum Leader

    Generally one takes measurements with the DSH off so that water side load does not skew your numbers.
  9. llaforest

    llaforest Member

    OK I will do that. But can someone tell what divergent LT1 and Discharge would mean?
  10. AMI Contracting

    AMI Contracting A nice Van Morrison song Industry Professional Forum Leader

    it could be ground getting colder and water getting hotter in buffer tank particularly on long cycles.
  11. llaforest

    llaforest Member

    The ground water has been steady for a while now at 47F.

    Without suggesting anything, I was thinking that we might have a leak in refrigerant... If I try to explain logically, it seems there is no inertia on refrigerant side. The air coil lowers it too much, the compressor rises it to much, like if the quantity was not sufficient for the machine size... I say that because it looks like the situation has been slowly degrading since the last two months.

    At first on stage 2 with sama water flow, we would have an LT1 of 37 and it has been going down to 24.5F in the last two months on regular basis with mostly same conditions.... I just don't have old number for the discharge... :( But today, without the DSH, it still the same at 205F with LT1 at 24.5F.
  12. AMI Contracting

    AMI Contracting A nice Van Morrison song Industry Professional Forum Leader

    Have we ever verified gpm in stage 2? If you are having lockouts, aren't you under warranty?
  13. llaforest

    llaforest Member

    The GPM is around 6, even going to 100% with 10-12gmp, the numbers above don't change much.

    As it is the water enters 47f and goes out at 42f. At 100% it comes out at 45 but my LT1 and discharge are unchanged or barely move.

    About the lockout, I know that with our climate here in Montreal, we are always running at the boundary of ClimateMaster open loop design. My concerns is more about the fact that the numbers are degrading in the last two monts. In the other house on the same water line with the 4ton TZ22, the numbers are steady since last year... Only with this new 3 ton TZ22, we are loosing more and more...

    Usually, if the LT1 is low, it means that incoming water, ambiant air are cold, thats fine and it usually reflect with low discharge around 150f. Now along with my low LT1, I have super high discharge at 205F... Leaving air is not super hot around 100f. It doesn't make sense. Ambiant air is around 70f in the house.
  14. AMI Contracting

    AMI Contracting A nice Van Morrison song Industry Professional Forum Leader

    My concerns are:
    1) I don't know what i can't see or you are not telling me
    2) I don't know if your readings are accurate.
    There was a run of trouble from a vendor that might interfere with txv. One cycle in cooling may help
  15. llaforest

    llaforest Member

    OK, so my numbers are not so odd for you then... Possible, I though they were but you are the guy with experience. :) We were planning taking manually the reading at the comp discharge, we will see.

    I will do a cycle in cooling if it might help. Not sure I understand what is txv and what kind of interference you are talking about though.

  16. James Franke

    James Franke New Member

    Two months ago I replaced a Friedrich 2 1/2 ton open loop with a closed loop CM TZ30. It has not performed well. It takes 4 hours or more to move from a 4 degree setback. It goes into stage 2 for a long time even when the setpoint is already reached. I had a high pitched noise a the "standard" CFM's. It's now at 650/1025 and sometimes the noise comes back.

    I also see a low LT1 of 15 degrees or lower with a LWT of 45 and a comp discharge of 204. The troubleshooting manual says the LT1 and LWT should differ by 5 to 10 degrees.

    I also have a CM TZ24 in parallel that has no problems. It's LT1 and LWT is in the 5 to 10 range with comp discharge 150 or lower.

    What's going on?
  17. llaforest

    llaforest Member

    The problem is getting worst. My LT1 is now 17f, discharge 215f. The leaving water is always around 42f, entering 47. Leaving air is around 97.

    What could make LT1 go lower and lower like that in the machine? Is it possible there is a leak in refrigerent?

  18. James Franke

    James Franke New Member

    Did you ever find an answer?
  19. AMI Contracting

    AMI Contracting A nice Van Morrison song Industry Professional Forum Leader

    "OK, so my numbers are not so odd for you then... Possible, I though they were but you are the guy with experience."

    I don't know how accurate your numbers are. I don't know how you are taking measurements (1 thermometer or 2, imbedded in air or water stream etc). Have we verified leaving water GPM? If so how? Persistent lock outs are not normal. Why are you not under warranty with the installing contractor?

    James, lot's of I've observations and questions for you, but this is llaforest's thread. Go ahead and start your own and we will try to help.
  20. llaforest

    llaforest Member

    Never found the reason why LT1 is so low (17-22F) on this machine... I keep an eye on leaving water but the delta is repsected and it never leaves under 42F...

    So why LT1 delta with leaving water is so big? No clue!

    It's still good on my other TZ22... LT1 28F, laeving water 40.5F

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