Upstairs AC zone not working
I just moved into a new house in November. It has central AC/Forced hot air and 2 zones. The zones split in the basement and are controlled via dampers from the main blower. In the winter, the heating system worked fine.
The previous owners disconnected power from the 1st floor damper and the linkage was broken that goes from the motor to the damper. After gluing the the linkage together so that it would open/close and applying power...zoning for the heat system worked properly.
Now it's time to turn on the AC and only the first floor t-stat will turn the AC system on. I switch both t-stats over to cool (new Honeywell programmable units), set them to call for AC...and only the first floor works. It works well when it's on.
From what I can tell, in "cool" mode, there is nothing telling the 2nd floor damper motor to open. If I manually rotate the linkage, the motor closes it again. Nothing I do allows the the upstairs t-stat to control the damper or AC unit when it's in cool mode.
Now, I only have 3 wires on the upstairs t-stat (R/W/G) and downstairs there are more (I forget all the colors.) Is this why my upstairs zone is not working? Is there a wiring scheme that doesn't have AC wiring going to the second zone?
In a pinch, I guess I could remove power from the upstairs damper motor, manually open it, and just have it cool the entire house. But that defeats the purpose of zones!! Help!