Can Someone help me install my thermostat from pictures?

Can Someone help me install my thermostat from pictures?

Sure, post wiring of old thermostat and wiring at furnace

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Thank you for answering. Here are pictures of my existing thermostat, the heater panel, and my ac panel.

The problem I’m having is the yellow wire leaving the thermostat doesn’t tie down on the yellow lug on the heater panel. It’s wire nutted to a white wire (out of the picture at heater panel ) that goes out to the ac comp. panel. And the red wire that comes back from the ac comp panel is tied down on “C” on the heater panel. I hope that’s not too confusing.

I can only post one picture per email. I hope you get the rest.



Warning - LONG Long-Winded!!!

Well, the Yellow Wire is the Cooling Wire. I’m trying to remember how it’s wired on my own system. Does it go to the control board? C is Common, and so you could have more than a single wire on it if you needed. So if You had an extra wire-free, not being used, then connecting it up to C for the thermostat and adding to the C on the heater board with that other wire would be OK.

If you don’t have that extra wire, that using the adapter and wire it in like it’s suppose to, and not worry about Y not being on the heater control board. Just wire up those wires the same way on the new thermostat. Whatever is going on with that red RC wire, you can clip the excess off and just have a normal end to connect. That Yellow wire for the Thermostat is working and turning on your AC.

A thermostat is just a fancy way to control a number of relays. It’s a 24 volt system. So you could manually touch the yellow wire to the red wire and startup your AC. Or the White wire to the red wire to start your heater running. The green wire controls your FAN.

So White is Heating Stage 1
Yellow is Cooling State 1
Green is Fan
Red is 24 Volts AC.
C is common.

So what I think they are doing is running the yellow out to your outside AC unit, and returning it to C common on the board. Now when your thermostat makes a connection, from RED, 24 volts to Yellow, and passes that down to outside to power up your AC unit and comes back to your common, completing a circuit. Right?

Think of it as plugging something into a power outlet in the wall for 120V. You have 2 plugs plus a ground. Ignore the ground. So you have a black wire on one side for power and on the other side a white Common. If you go into your circuit breaker all your common wires are together. Of course, all your ground wires are together also and they’re all at the same point and connected together anyway. Forget all that. The point it, you have power coming in, going through your device to do a job, and coming back out through the other plug. It’s AC so it’s really moving back and forth, alternating current (AC) This would be what is happening at the Thermostate, right?

24V power is coming from the Red Wire. You turn on your AC, it connects your Red Wire to the Yellow wire so the 24V AC travels down the yellow wire going to your outside AC unit to power it up, and then returns back to your house into your heater board onto the common terminal completing a circuit. Your Termostate will turn on the fan by making a connection from Red to the green wire also.

So you really should ignore your heater board, other than because you don’t have a C wire at your Thermostat. if you can easily add one, great. If you can’t, not the end of the world. That is what the Adapter is for.

The C wire adapter is used to send the power down the G wire if you don’t have a C wire or extra wire to use as a C wire to go to the thermostat. That does make some sense. Though I would assume you can’t control the fas as well, like have it running to get the last of the heat out when the heater turns off? Things like that?

If I needed to I could have replaced my thermostat wires when one that had more wires if I needed a C. It’s such a short, easy run from my heater to my Thermostate that I could have done that. But I had a couple of extra wires not used, wrapped back around. So I just used one for C. Really, all you need is to run a second wire from that C terminal on your heater board to the Thermostat. or just use the adapter. I think you’re overthinking it. Don’t mix your 2 red wires up on the heater board. That would be a mistake!!! That would be BAD!!! Make sure you turn off the power first before messing with the wires. It’s 24 volts and so won’t kill you, but there is 120V coming into the board and converted to 24 volts the system runs on.

Have I confused you? To much?

I’m looking at your last picture and don’t see the yellow wire? I see the contactor there in the middle. Those 2 purple wires on each side, power the coil in the contactor and pull it down which allows the fan motor and compresser to run on what looks like 120V? I see a Black, White and ground wire there. I see a bit of the capacitor there on the left that kickstart your motor and compressor to run. Basically, your Thermostate is going to send power out to this AC unit and cause that contactor to energize which sends power from the bottom up through it to the black and red wire to run your compressor and fan motor. So I see there on the right side what could be the red wire going back to the heater board? The white wire there going where? Assume it meets up with the yellow wire someplace I can’t see from your picture. Is the yellow wire from the thermostat meeting up with a white wire someplace around the heater board, just not connected to the Y terminal? That would make sense.

So the Yellow wire from the thermostat connects up to a 3 wire cable, the green wire is not used. Yellow to the white, runs outside to your AC unit, connects to the purple wire of the contactor coil, comes out the other side with another purple wire and connected to the red wire, that goes back into your house to your heater board C, Common connection. This would make a complete circuit. That makes perfect sense to me.

So when you turn on your AC, power flows from the Red wire at the thermostat, to the Yellow wire to the white wire to the purple wire outside, Energizes the contactor to power up your Fan motor and compressor, goes back out the other purple wire, to the red wire, to inside your house to the C terminal completing the circuit.

Your Thermostate is not a magical box. It’s a fancy switch. An old fashion liquid mercury switch did the same thing in the past. When the temp got cool enough, it caused the mercury to move and jump a connection to link 2 wires together. That’s would turn your heat on and the fan would start running.

A thermostat has small relays that allow low power voltages to open/close a relay to allowed higher voltages to pass through. In effect linking the wires together to cause a reaction. So you set a temp that is lower than what your house is, that will power up a rely to connect the Red wire to the Yellow wire, sending power from that red wire down the yellow wire. It will then turn on the relay for the green wire to turn the fan on/off as it needs which is also being linked to the red wire. The thermostat is taking the house temp, and causing things to turn on and off as needed. When it comes down to it, it just a fancy mercury switch of years ago.

I thought these systems ran on 240V, not 120V? I see Black and White and think 120V. Well, it really doesn’t matter overall I guess. All that matters is the thermostat sends power outside to pull down that contactor. It’s basically an Electrical switch. So just as you would flip a light switch UP to turn on your lights, well in this case you send power to the coil and that pulls down the switch. In fact on this contactor, the left side looks like it’s always connected. The right side is the side that moves up and down. Up, no power going through, down, power is going through which completes the circuit and things start running.

At work, I’m used to larger contactors with 3 wires going in and out. Because they’re for 3-Phase motors. I’m normally dealing with 480V 3Phase things. Running much larger compressors and 2 or 3 fans. I have to replace those once in a while. No need for capacitors to kickstart compressors or fan motors like these small home systems. No way am I an HVAC expert by any means. We have experts we can call in for bigger issues. I pretty much do some of everything at the factory and it’s mostly me. Installing some new $100K industrial machine, ME! Nothing just plugs in. I have to figure out how to make it work and generally in a washdown environment.

So some of this HVAC stuff I can figure out. Give me enough time. This home stuff is really a lot more basic. Less to it. Our Refrigeration and freezers are all controlled by a special Computer. While I can understand some of it. I can work on some of the electrical stuff, and swap out a bad fan motor, which I need to do one on the roof when it stops raining as I have some free time, I’m not an expert. I can only make guesses at what I see from your 3 pictures. But I think I’m right. I have installed a few Ecobee’s for myself and others. Gotten the C wire connection setup. One was on a 2 story house with a duel setup. That took a little bit to figure out what the F was going on. It was some sloppy work that I had to fix also. Got it working. I know a lot in many things which is good for my job, but I’m not an expert focused on one type of thing. One day I may be installing a new industrial machine, the next fixing a lawn sprinkler, to the next setting up new Car Charging stations, to replacing broken Quarry tiles, to servicing the Air compressors to the Steam Generators. To fixing a machine that stopped working in production with all eyes looking at me as the clock is counting down.

So it’s thinking things through logically. I’ve picked up a lot of skills over the years. I gain more skills and make myself even busier now doing those things we would have had outside company’s do. Always learning new things. Which is why I’m long-winded here. Trying to teach others things so they can learn themselves. Figure it out. Think things through, which in turn can help you save money!!! When you don’t have to call in an HVAC person to fix something not too hard, You’ll save a lot of money!!! When I have to call in the commercial HVAC company, that’s basically a $1000+ bill right there!!! This is why I try fixing things myself first. If I can figure it out, it’s a huge saving. So explaining what is going on, people can see it’s really not all that magical.

It can get harder if say your Furnace board goes bad. Mine has in the past. In fact I have a spare one just in case that happens again. I can swap in a new one if need be and not suffer in the heat or cold. Figuring out if you have a bad board, or maybe a safety sensor is bad. There are ways to test these things, a number of them with a simple voltmeter. I have to say, googling answers to your issues. Seeing how to do something on Youtube can really help you. Finding answers to what to test for, it’s great. It’s a huge resource. In fact, it recently helped me to figure out why my Hot water heater stopped working. Replaced the sensor, still wasn’t working, figured out how to actually reset it. which was a little complex, but it worked and has been running great since then. I saved a bundle of money not having to call someone in to fix it for me. I learned something new. I replaced that Hot Water heater 5 years ago myself when the old one went bad and was leaking.

Again I think you may be overthinking it. So wire colors may not always match what you think they should be. Missing connection points like Y on the main heater board may throw things off for you. This is why they have you take a picture and label the wires. Why you can’t just assume something. Your AC has been working as it is, so that Yellow wire is good. Ignore that it’s not on Y on the main control board. Again overthinking things. I think I explained why that is pretty good right?

This is why you ignore all this outside stuff. You’re connected the thermostat to the wires you have. If you don’t have a C wire, you have a couple of opinions. If you can easily add a C wire as you have extra wire(s) not being used on each end, great. Makes things simple. Pick a wire that is not being used. The color really doesn’t matter so long as it’s the same color on each end. So if you have a free black wire for C, great, make sure it’s black on both ends. If you have no extra wires use the adapter it came with on the furnace end. Connect the wire you have to it as it tells you. Then you don’t have to worry about C on the thermostat end, Connect just the wires you have. You’ll set up your Thermostate for that adapter. Done!!! Move o to setting up your Thermostate settings, if it powered up. If it didn’t power up, you did something wrong. In most cases it really shouldn’t be all that hard. If you have to in the end, call in an expert. Maybe you have a friend that can do it for you. At least get it working and you can finish it.

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The yellow Y is just going straight to the outside AC condenser, the other wire at the condenser goes to C so when the thermostat calls for cooling, it’s a completed circuit.

You just need to install the C wire adapter at the furnace. During install, tell the app the wires you have at the thermostat, then install the adapter, you’ll have 2 wires on the C terminal. You just won’t connect the Y from the adapter to the control board. I believe this should work. Make sure at the thermostat you label the G wire as C and connect it to the C terminal on the Wyze thermostat.

@JBDragon wow, I did not have the patience to read more than 30 sec lol


image Take this blue wire out from behind your thermostat.

Find the other end of the blue wire in your furnace where the thermostat wires come in.
Attach it to C with the red wire that is already there. There will be a Blue and red wire on this terminal when it is connected properly.

Attach the wires to your wyze as follows:
Yellow > Y1
Green > G
Red > Rc
White > W1
Blue > C

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These giant walls of text are why I just started drawing diagrams in paint. Trying to explain the wiring is more difficult than just showing a diagram of how everything is connected :slight_smile:


Nice catch on the blue wire

Thank you all for your quick responses. I’ll give it a try.

That’s OK!

Ya, I can just make out that blue wire at the thermostat. I said, if there is an extra wire folded back, or wrapped back around, great. use that blue wire for C on the thermostat. But that Blue wire also needs to be connected to C next to that red wire on the main heater board also. So there should be a corresponding blue wire folded back on that end also not being used. Can’t connect one end and not connect the other as nothing would happen.

I saw that Blue, but I didn’t think it was a wire, just the outer insulation. That picture is not clear to me. It may be easier to tell looking at the main board as you can see all the wires more clearly and if there is 1 or more not hooked up. Then go ahead and pull on the wires from the wall carefully and see if there are 1 or more hidden behind the wall you couldn’t see. This is a pretty normal thing to do in hiding extra wires.