Texas Bosch SM60 coil failures

Discussion in 'Maintenance and Troubleshooting' started by KJW, Oct 3, 2019.

  1. KJW

    KJW Member

    Hello to the think tank !!

    I have the BOSCH SM60 that is four years old. We are now on the third coil. Has anyone else had issues like this? Our HVAC subcontractor recently told me he recently replaced numerous coils but Bosch is acting like this is new news to them...
  2. waterpirate

    waterpirate Well-Known Member Industry Professional Forum Leader

    Open or closed loop? The reason I ask is it is all about water quality when it comes to warranty.
  3. KJW

    KJW Member

    Hmmm. Maybe I missing something here but I am taking about the coil in the unit. We have a closed loop system but the coil (condensing) doesn’t have anything to do with the water or the loop... multiple systems installed over the years but only these Bosch units are having condenser failures...
  4. arkie6

    arkie6 Active Member Forum Leader

    You have two heat exchanger coils in a geothermal heat pump; the flat refrigerant-to-air finned coil and the round water-to-refrigerant insulated coaxial coil. It sounds like your problem is with the refrigerant-to-air coil. Are the tubes in your coil copper with aluminum fins or is your coil all aluminum? I know that some manufacturers have switched from copper/aluminum coils to all aluminum coils due to formicary corrosion (google that for more info).
  5. KJW

    KJW Member

    That’s what I am talking about - the refrigerant is leaking down again, failures are being found in the welds or bends in the coil on the unit. Bosch is using aluminum now from what they are telling me. This is an sm60 and was supposedly one of the “best”.
  6. KJW

    KJW Member

    AF0F5E4C-A2C6-458F-9F14-176B53C3C880.jpeg Coil replaced - on the 3rd one now - covered in oil on the the right side where all tubes start... considering Texas Lemmon law if we have one more failure... Bosch is staying no issues with their coils supposedly but installer reports multiple failures so, the coil is off to the lab for testing...

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