Results 1 to 7 of 7
  1. #1

    Unhappy

    I have an American Standard 16 SEER 2 Ton Outdoor Unit with a 1.5 to 3 Ton Variable Speed Air Handler. The variable speed air handler is set to match the 2 Ton Outdoor Unit. The airflow is set to 100% and 400CFM/Ton. When the American Standard Touch Screen Thermostat with Dehumidification Control calls for cooling the VS/AH starts to spin up then slows to a very low speed and continues to run at low speed. The suction line then starts to ice up.

    Any help with what the problem could be is greatly appreciated.

    This unit is equipped with a TXV valve and TXV sensing bulb. Installation instructions indicate that overheating of the sensing bulb will affect the functional characteristics and performance of the air handler. Could this issue be caused by a defective or damaged TXV sensing bulb?

  2. #2
    Join Date
    Nov 2005
    Location
    Blind And Sons/Tri County
    Posts
    49
    How long has this system been installed seems you have some good knowladge of the system

  3. #3
    Join Date
    Jun 2006
    Location
    New Jersey
    Posts
    4,333
    If its new then it might be a wiring issue. Most VS air handlers need a jumper between Y1 and Y2, when using a single speed condenser.

  4. #4
    Join Date
    Nov 2005
    Location
    Blind And Sons/Tri County
    Posts
    49
    Make sure they ran y from the t stat to the furnace

  5. #5
    Join Date
    Nov 2005
    Location
    Blind And Sons/Tri County
    Posts
    49
    if you jump on a trane y to o and 5and 6 on for comfort R

  6. #6
    The system is newly installed. The outdoor unit has a 2 stage compressor. I have an identical 4 ton unit with the matched VS/AH and it is working fine.

    I believe the wiring is OK. It is the same as the 4 Ton unit. Install tech burned control wires from AH to Outdoor unit and re-wired. I have not verified that the repair is correct. Dip switches 5 and 6 are not set to comfort R yet because of my issues. R to O is jumpered at the AH.

  7. #7
    Join Date
    Nov 2005
    Location
    Blind And Sons/Tri County
    Posts
    49
    R to O ? He does have y and ylo for 2 stage compressor right? Y from the tstat has to go to the board

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