Ecobee Smart thermostat Installation in an Old Trane PTAC
November 27, 2019/
Last November my Trane PTAC stopped working for me. I thought it was a great chance to upgrade my thermostat to a smart one as well. Most of my friends use Nest but my PTAC guy recommended Ecobee so I went ahead and loved IT! Therefore, I decided I want to do it for my daughter’s PTAC but my PTAC technician told me it is not worthy his time and my money to invest an Ecobee on a 15 years old machine. That’s when I thought I could do it myself so I started to research. However, there are not many tutorials out there to guide people to install a smart thermostat on a PTAC so I hope my experience can help someone who is looking for installing a smart thermostat in a nontraditional way.
1. First, you must find the manual because it contains important information about how to set up the PTAC to be remote thermostat ready. Based on the diagram, Switch number 5 and 6 are the ones that I need to pay attention to.
2. Control Location Switches Diagram. I tells me that SW5 and SW6 need to be “ON” for my purpose and I didn’t touch any setting for the rest of the switches.
3. Control Board User Inputs first half. This diagram tells me that CN-ZONE is the location the zone control wired to and CN-EXT1 is the new location that my smart thermostat needs to be wired to.
4. Control Board User Inputs second half. This table tells me that what do “GL”, “GH”, “O”, “W”, “Y”, “R”, “C” mean in the CN-EXT1 location.
5. This is my old PTAC thermostat “zone control” which attached to the top of my PTAC.
6. This shows where the zone control unit is wired to on the control board.
7. A close-up look of the control board and the DIP switches.
8. I unplugged the Rectangular Power Connector of the Zone Control Unit.
9. I took the 4 pins connector from the broken PTAC that was in my room and the other one from my kid’s room.
10. I joint two 4 pins connectors together because I can’t find a 7 pin connector that fits my control board.
11. I labeled the wires that I needed to use and attached the unused wires with wire connectors.
12. I labeled the wires referred to the diagram’s instruction. GL – Fan Low. GH – Fan High. W- Heating Input. R – 24 VAC. Y- Compressor Input. C – Common.
13. I plugged the wires to the proper terminals. The wires that the Ecobee used were 18/7 Brown Solid CU CL2 Thermostat Wire.
14. I labeled the wires in the 18/7 Brown Solid CU CL2 Thermostat Wire. GL – Fan Low. GH – Fan High. W- Heating Input. R – 24 VAC. Y- Compressor Input. C – Common.
15. The wires from the PTAC control board and the wires from Ecobee were connected with wire connectors. Please make sure C goes with C, W goes with W etc…Please make sure any wire that is not connected to anything needs to be connected to a wire connectors and secured with electrical tapes.
16. After wiring and checking everything was secured with wire connectors, I moved away anything that’s flammable and plugged in the PTAC unit. Once the PTAC was on, Ecobee turned on too.
17. Ecobee showed me a code and I used it to register on ecobee.com.
18. I only needed to wire 5 terminals. That is the reason it only shows 5 terminals are connected. G – Fan High. W1- Heating Input. Rc – 24 VAC. Y1- Compressor Input. C – Common.
19. I hid all the wires in the PTAC unit and instead of installing Ecobee on the wall, I purchased a stand to put my Ecobee. The wires went from bottom of the stand and were connected to the Ecobee‘s back plate.
