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  1. #1
    Join Date
    Jul 2010
    Location
    Michigan
    Posts
    17

    Trane 6 ton closed loop A/C quit, Heats.Help!

    Hi, Two weeks ago Saturday evening I noticed the a/c seemed very cold. Sunday morning registers blowing 75 degree air. Compressor not running. Shut system off and heard a rush of refrigerant in system (equalizing pressure?). Start up and compressor kicks off after about 20 seconds. Tried in heat mode system runs for 10 minutes heating house UGH! It had a problem last year in the heating mode (low pressure cutoff) and tech replaced TXV. System then ran well till now. Gauge on high side climbs to 450psig in 10 to 20 sec and compressor shuts off. Acting like something is plugged.
    Freon charge good.
    Tech replaced TXV = no change.
    Replaced reversible drier=no change.
    Replaced reversing valve=no change.
    We are stumped!
    model #GSUF0721AA1L120T serial#W95K34650 TRANE installed 12/97 scroll compressor.
    Closed loop 6@600ft. pipes filled with distilled water/antifreeze.
    Tech is a wonderful guy. Told me he is not charging me for labor and will discuss parts cost with owner since problem hasn't changed. He has about 6 hrs into it so far.

    Any suggetions?

  2. #2
    Join Date
    Jul 2010
    Location
    Andalucia
    Posts
    3,220
    Does the condenser fan come on when unit comes on in cooling?
    "War is cruelty,and you cannot refine it." Sherman to the leadership of Atlanta prior to burning the city.

    "Common sense is the collection of prejudices acquired by age eighteen."
    Albert Einstein

    Romney campaign: "We're not going to let our campaign be ruled by fact-checkers,"

    Lindsey Graham: “We’re not generating enough angry white guys to stay in business for the long term.”

  3. #3
    Join Date
    Jul 2010
    Location
    Michigan
    Posts
    17
    Hi and thanks for the fast reply. We have been miserable for two weeks and feel bad for all those who cannot afford a/c.

    If you mean the main blower fan, then yes, it comes on as soon as the system triggers the compressor and it remains on after the compressor shuts down.

  4. #4
    Join Date
    Jul 2010
    Location
    Andalucia
    Posts
    3,220
    I'm sorry this geothermal he should check the water supply. I thought it was air cooled.
    "War is cruelty,and you cannot refine it." Sherman to the leadership of Atlanta prior to burning the city.

    "Common sense is the collection of prejudices acquired by age eighteen."
    Albert Einstein

    Romney campaign: "We're not going to let our campaign be ruled by fact-checkers,"

    Lindsey Graham: “We’re not generating enough angry white guys to stay in business for the long term.”

  5. #5
    Join Date
    Jul 2010
    Location
    Michigan
    Posts
    17
    No Problem.

    I asked him about the possibility of: what if, although the loop water pump is running, there is low volume? Could it cause the high pressure cut off we are observing? He said since the heating mode is producing for at least 10 minutes there would be enough for cooling...

    This is a toughie. He has run out of ideas, replacing parts in order of cost and possibility of being defective.

  6. #6
    Join Date
    Jul 2010
    Location
    Andalucia
    Posts
    3,220
    Not much experience here but check water temp,amount of flow, scaling in heat exchanger, pump operation,reversing valve
    "War is cruelty,and you cannot refine it." Sherman to the leadership of Atlanta prior to burning the city.

    "Common sense is the collection of prejudices acquired by age eighteen."
    Albert Einstein

    Romney campaign: "We're not going to let our campaign be ruled by fact-checkers,"

    Lindsey Graham: “We’re not generating enough angry white guys to stay in business for the long term.”

  7. #7
    Join Date
    Jul 2010
    Location
    Michigan
    Posts
    17
    Those are some excellent ideas!
    Water temp would verify flow and eliminate the possibility of a air problem due to leak.
    I thought about the scaling problem since we have well water and called trane in 97 before install to make sure distilled water would not harm system (since it is an aggressive water looking for minerals to balance itself). This would eliminate scaling would it not?
    Reversing valve was replaced two days ago as a last resort.

    Keep on brain storming there must be an answer since the day before it quit it was blowing cold cold air.

    Thanks Again for taking time to reply!

  8. #8
    Join Date
    Jul 2010
    Location
    Michigan
    Posts
    17
    Upon further investigation I decided to check if the system would heat after drier and reversing valve were installed. Opened up the water loop pump box so inlet and outlet temperature difference could be felt to verify that there is water flowing. Before system started I noticed both fuses for the two pumps are blackened. Checked for continuity and both are blown.

  9. #9
    Join Date
    Jul 2010
    Location
    Michigan
    Posts
    17
    Update: Yesterday: Loop has two 240v circulator pumps wired to 2 fuses. Pump 1 checks at 39.6 Ohms & runs. Pump 2 Checks infinity and blows fuses. Removed pump 2 from circuit and A/C works.
    Today: 24v xmfr popping reset. Reversing valve solinoid coil L30-12 red 24v appears darkened around 1/2 inch center of coil and checks 0 ohms. Removed one wire, reset xmfr, stays on and compressor starts (Ugh heat mode!) I want to know if this coil is bad so tech can bring one when he comes to replace pump on thursday.

    Anyone know the resistance spec of a good coil?

    Now I wonder if Tstat is going bad which would be the reason the A/C was so cold(running excessively) possibly causing the pump failure? He's bringing a new one also.

  10. #10
    Join Date
    Jul 2010
    Location
    Andalucia
    Posts
    3,220
    Quote Originally Posted by Die Maker View Post
    Update: Yesterday: Loop has two 240v circulator pumps wired to 2 fuses. Pump 1 checks at 39.6 Ohms & runs. Pump 2 Checks infinity and blows fuses. Removed pump 2 from circuit and A/C works.
    Today: 24v xmfr popping reset. Reversing valve solinoid coil L30-12 red 24v appears darkened around 1/2 inch center of coil and checks 0 ohms. Removed one wire, reset xmfr, stays on and compressor starts (Ugh heat mode!) I want to know if this coil is bad so tech can bring one when he comes to replace pump on thursday.

    Anyone know the resistance spec of a good coil?

    Now I wonder if Tstat is going bad which would be the reason the A/C was so cold(running excessively) possibly causing the pump failure? He's bringing a new one also.
    O ohms or OL? I'd tell him to bring a coil. Depending on how reversing valve engages you may still have cooling. I forget how Trane works.
    "War is cruelty,and you cannot refine it." Sherman to the leadership of Atlanta prior to burning the city.

    "Common sense is the collection of prejudices acquired by age eighteen."
    Albert Einstein

    Romney campaign: "We're not going to let our campaign be ruled by fact-checkers,"

    Lindsey Graham: “We’re not generating enough angry white guys to stay in business for the long term.”

  11. #11
    Join Date
    Jul 2010
    Location
    Michigan
    Posts
    17
    Thanks. Trane defaults to heat mode if coil fails. So exhausted with not having a/c I resorted to pulling one coil wire and used a permanent magnet which draws the soleniod to the cool position. This is one amazing magnet, it is about 1/2x1/2x3/4 and if you get your finger tip between it and to what you are sticking it you will lose a chunk of skin. This could make you a hero if your customers coil fails and you have to leave them without a/c. Not intended to be a permanent fix but will get them cool air while you round up a coil. (Coil stays energized as long as tstat is set to cool so magnet only mimics this setting). Magnet placed on side where attachment screw threads in draws solenoid to cool position. You can hear it click/shift just like coil does.

  12. #12
    Join Date
    Feb 2010
    Location
    In a boiler room
    Posts
    7,046
    Quote Originally Posted by Die Maker View Post
    Update: Yesterday: Loop has two 240v circulator pumps wired to 2 fuses. Pump 1 checks at 39.6 Ohms & runs. Pump 2 Checks infinity and blows fuses. Removed pump 2 from circuit and A/C works.
    Today: 24v xmfr popping reset. Reversing valve solinoid coil L30-12 red 24v appears darkened around 1/2 inch center of coil and checks 0 ohms. Removed one wire, reset xmfr, stays on and compressor starts (Ugh heat mode!) I want to know if this coil is bad so tech can bring one when he comes to replace pump on thursday.

    Anyone know the resistance spec of a good coil?

    Now I wonder if Tstat is going bad which would be the reason the A/C was so cold(running excessively) possibly causing the pump failure? He's bringing a new one also.
    Are you serious?? He swapped all those parts without checking the water flow? Wow. Is he a tech or just a friend that "knows about geo"? or is it diy?

    Water flow would be the first thing to check when there is hi head in cooling.

  13. #13
    Join Date
    Jul 2010
    Location
    Michigan
    Posts
    17
    Serious. I agree. Not a DIY or friend.

    I am not a HVAC pro but used to be a master auto mechanic (26 years ago) prior to becoming a die maker. So refrigeration experience is limited. I think where he was thrown off was the assumption that since system ran in heating mode, producing heat for 10 min loop must be good. Apparently the heat produced was plenum fan robbing heat from freon and keeping it cool enough to not blow any limits.
    They have not charged me for anything yet. We'll see how this plays out.

    Now the problem is the new solenoid coil overheated and is shorted out after 2 hours of AC. They were back today checked all circuitry didn't find anything that would cause coil to fry. The only thing I can see is the new reversing valve solenoid from trane allows the coil to move side to side about 1/16 inch(end to end is snug). The original valve had a metal bracket around the coil and the solenoid had a slightly raised shoulder which seems to hold the coil centered around the solenoid. They are to contact trane Monday to see if not being centered exactly is causing coil to overheat.

    So in the meantime they put my magnet on solenoid and ac is cold, ahhh.

    I'm not angry. I know the mercy I give is the mercy I'll receive. None of us is perfect and we all have bad days. Bet they don't make that mistake again.

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