I think that's a great plan - it's genuinely the best answer. Again, if possible, I would run 18-7 or 18-8 stat cable (either or both should be readily available at a big-box store or local hardware store). That will future-proof you for potentially installing multi-stage heat/cool in the future.
Just wrap any unused wires back for now (just like the 3 unused wires now coming from your condenser) -- whatever you do, don't cut them back
And if your A/C doesn't work right after you hook it all up, try connecting the stat's Y and the condensor's Y both under the Y terminal on the control board. I can't believe that would harm anything in any way -- it's definitely a more common way to wire those things.
Ooof, one last important thing -- always kill power to the furnace when messing with any of that wiring. Nothing's really a shock hazard to you, but it is possible to blow a fuse on the furnace control board (or totally fry it). Killing power ensures that won't happen.
Hey Guys, I just got back and here is what I did. I connected the C wire from the T6 to the circuit board and put everything back together. After much testing, power source says mains so that is OK. I did find however that if the fan is set to auto and you try to cool the house, the cool on icon flashes and there is no cooling. If the fan is on and you set it to cool, the cool on flashes and then goes steady and cooling is started and working. Since then I have connected the orange and red wires to the Y terminal as instructed by "hydro311" but I still have the same problem. No cooling unless the fan is set to on. It is like the cooling function is not starting the fan when it is set to auto and the cool icon just flashes. It knows not to cool unless the fan is running. I am ready to pull my hair out, which won't take long. I guess I need to get a HVAC license so I can fix my own stuff. One good thing about all of this is that I have all winter to figure it out. Heating works OK.
Here's another stick in my craw. With the batteries in the T6 the device page says powerSource :mains. If I take the batteries out of the T6 and power it through the C wire that I hooked up the device page reads powerSource:battery. Now how does this make sense?
I am thinking I need to rethink this whole thing. If I want to make this work correctly, I think I should replace the thermostat cable with a 8 conductor cable and get a HVAC professional to hook it all up correctly. Being cobbled together like it is now is not the correct way to go.
I have been experimenting with setting up automations that send out a command and 10 seconds later send it out again. Some testing has been promising. I don't think this is the proper way of doing things but it may work. My premise being that if the T6 is in sleep mode the first command will wake it up and same command 10 seconds later sets the temp setpoint. Unless I want to connect the T6 the correct way I think I will try this. Thank you guys for all your help you are amazing.
I just wanted to let you guys know that I am getting along well with the T6 Pro.
I have made my automations so that the rules send out a command and then 10 seconds later after the T6 has came out of sleep mode and send the same command again. I guess if the T6 is not in sleep mode and I do this it just gets 2 of the same command. I don't think this will hurt anything. It works pretty well as I have not had any automations that did not run. I think this will be sufficient until I can get some re-wiring done. Thanks for all your help.
