Do I need the c wire adapter at all then?
Nevermind. Wyze support and I ended up frying the thermostat.
No, you would not have needed the C adapter if the blue wire was hooked directly up to C. What did support have you do that fried the thermostat?
They had me switch the yellow and green wires at the thermostat. I hooked the blue wires like you said and had power but the heat wouldnât go on. Then the Wyze thermostat had no power at all after I tinkered with it a bit more and then it zapped out. Theyâre sending me a new one free of charge. Iâm guessing we shouldnât have switched the green and yellow wires at the thermostat?
Why is the yellow wire going to the c terminal in the furnace? Any idea? The told me that Iâll have to hire an electrician if I want any further help.
The yellow wire goes to C because it is going to feed the outdoor unit. When you hooked up the wyze, did you put the yellow wire on G like your old thermostat, or on Y?
I can continue to help you, but I want a picture of your wiring in your outdoor AC unit, as well as a picture of the back of that furnace board so that I can see where those terminals connect to.
Make sure the power is off before opening your outdoor unitâs access panel, and before moving that furnace board to see the back.
I expect that this will be the diagram for your system.
I really appreciate the help. Thank you for taking the time. We donât have an AC unit, we use window ACs during the summer so I donât know where the yellow wire is going. I put the yellow wire on Y. Iâm guessing thatâs what caused the thermostat to fry. The board in the furnace is very difficult to move so the pictures I have may be of little use but Iâll send them anyway.
Can you follow the thermostat wire inside the house and see if there are any splices?
If you donât find any splices, then Iâm going to assume you have a straight run, and your old thermostat was just hooked up incorrectly, but because you never had the thermostat running in cooling mode and because furnaces generally run the fan by themselves, it wasnât a problem.
In this case, You would connect the wyze as follows: red to Rc, white to W1, Blue to C, Green to G.
The reason that hooking up the Yellow wire to Y caused a problem would be that because it is connected to C on the furnace board, it would create a short circuit when it was switched on,
Do you know what model furnace you have? What fuel does it use? Do you have a whole house humidifier?
Can I get an overview photo of the furnace, so I can see all the wires and where they go?
What if my control board has no C-Terminal? I am lucky that I have a spare wire running from the furnace to the Thermostat (blue). I just donât have a âCâ terminal on the board to connect it to. This picture is pretty close to the board in my furnace. I have a Spade connection for the R, G and W but no C. Goodman Furnace Terminal Board|614x500
Your wiring diagram kind of looks like mine configuration. My Yellow goes from the Thermostat to the outdoor unit, and the other wire from the outdoor unit goes to the unit chassis in the furnace
The wires coming from the Outside unit are red and gray/ The Y (yellow) wire connects to the, in this case< red wire to do to the unit. The other wire which in this case is gray goes to an unmarked screw on the unit.
do you have a not quite so zoomed in image?
They have the common for the A/C tied to ground, which might work, but Iâd still like to see where the other side of the transformer goes.
HEre is the wiring Diagram, I also post a picture of the wires they go in to the white square terminal block
I see in the upper diagram the path that goes to the chassis is labeled with a C. I am assuming that I can use the Chassis as my c âterminalâ
According to the schematic, you could use chassis ground as common, the only thing bothering me is that I cannot see where the common from the board ties into ground in your images. The green wire appears to be coming from the supply, not from the transformer or the board. It might be internally shunted to ground through the transformer though, and the A/C system appears to be using it as common, so it should be a good enough connection for the wyze to use to power itself.
To clarify, you would use the wire that the AC unit uses as your common wire, and not bother tying another wire to chassis ground.
I still do not have a zoomed out image that shows enough of the picture to tell if you need the C adapter, but will assume that you do not have an extra wire in your run that is currently unused that could be used for C.
block diagram:
After I saw that the C wire in the diagram went to the chassis it al made more sense. The Green Wire is actually coming from the Board. There are connection points on the board for the R, G, and W. The Y from the Thermostat runs through the furnace and directly out to the AC unit and does not actually connect to anything in the furnace (except the wire coming in from the AC unit basically like you show in the graphic) . The C wire from the AC unit comes into the furnace and goes to the chassis. I am actually lucky that the wire bundle that goes between the Furnace and the Thermostat has an unused wire. So I believe I can wire the C terminal on the Thermostat to the chassis connection in the furnace and not use the C-Adapter at all. I think I have that right. I am using a terminal strip to neaten up the installation.
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Yes, if you have an unused wire on both ends, it is better to attach it to C than to deal with the C adapter. If it doesnât work with that wire connected to C on both ends, that means that there is probably a splice somewhere and they decided not to connect the unused wire in the splice- then you would have to either find the splice and fix it or use the C adapter.
It is powered up! Trying to get through the WiFi connect. Not having any luck. Starting to get cold. I guess itâs time to search the forums for the new problems Solution.
Thanks for the help on the wiring!
Hello, I have R, W, Y and G connected to existing thermostat. Wyze compatibility check indicates it will work WITH the c-wire adapter. All good. However the control board in neither of my furnaces contains connection for the c-wore adapter that resembles that in the video - they look older. I know what is roughly 18 years old. I previously had a Mest and it worked fine until I dropped it.
