I have a 3 year old Trane Furnace TUD1A040A9241AB with a 2 ton Cooling evaporator 4TXCA024BCHCBA. I believe it is a single speed blower or if not, I would like to figure out how to limit/eliminate the highest speed. It is noisy! Have to constantly change the TV volume based on if it is running or not and now with COVID19 and wife working from home, she can't hear on conference calls when it is running.

I heard there are aftermarket kits that can vary the speed (with some type of rheostat?) that have two thermistors both upstream and downstream of the blower. Mainly need to solve this issue with AC mode as we live in a condo in Florida and rarely even need to use the gas furnace as our elderly neighbors seem to keep their condo's so warm that our condo never gets cold in the winter.


  • Why not just disable stage 2 ? This will affect the efficiency.
    – Ed Beal
    Apr 1, 2020 at 16:24
  • Trane doesn't make finding installation and wiring diagrams online easy, but many blower motors are multi-tap motors. Maybe if you take and post a photo of the diagram behind the cover you might be able to get some help. Apr 2, 2020 at 1:07

1 Answer 1


Try to find the installation papers for the furnace and check the installation specs. Most blower motors are 4 speed. As far as the noise is concerned, I just replaced my 20 year old furnace with a new Goodman unit and it is very loud compared to the old unit. With most of the newer units today, you can not just reduce the blower speed since it may cause the heat exchanger to over heat. I would call a Trane guy and ask for advice.

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