Help installing C-wire adapter needed

Have run into some issues installing the C-wire adapter. First the wires going to the controller board on the air handler (hard to work in crawlspace over garage) are as follows
Wire color Terminal label
Yellow Y1
White/Blue W2
White W1
Green G
Brown C
Red R

Which of these attach to the following terminals on the C-wire adapter
I assume Green goes to G, Red goes to R, and Yellow goes to Y , but does White go to W or is it White and Blue?

Do I wrap the ends of the unused wires with insulating tape and leave them in the air handler so I can reconnect them if I have problems with the Wyze thermostat and have to use my old one?

Finally the wires do not screw into the controller board but are inserted in a connector that is plugged into the board as shown in photo below. Does anyone know if those wires can be released from that type of connector so the wires from the C-wire connector can be inserted into it and then plugged in? If not, would you cut the connector off leaving some wire sticking out and then solder the wires from the C-wire adapter to them.
Any assistance appreciated.

Post a picture of the wiring at the old thermostat

The thermostat connections are
W2 white
G green
W blue
Y yellow
RC red
there is a jumper from RC to R

Photo follows

is there any extra unused wires at the thermostat? sometimes there’s one wrapped around the cable. If you don’t have a unused wire you’ll have to install the adapter.

The wiring/connector at the control board look factory, follow the wiring & see if it’s going to wire nuts connecting the factory wiring & the wiring going to the tstat. This is where you’ll want to wire in the adapter.

During install, the app will tell you exactly how to wire.

Find the other end of those wires and look for wire nuts. If the W1 and W2 wires are currently wirenutted together along with the W2 (white) wire from the thermostat, then the blue wire from your thermostat is actually a O/B wire and you have a heat pump. Normally, this is the case when the W2 wire is white and the “W” wire is blue or orange, but not always.

We do have a heat pump. The wiring is a a rat’s nest with the wire nuts clumped together. From a quick look today I could not be sure which wires are connected. I will try to sort it out tomorrow and report back.

Thanks to you and Ken S.

I think I now have a good handle on the wiring. Leaving the nest of wire nuts next to the air handler controller are two groups of wires. One set of wires runs back towards the thermostat and matches the number and color of the wires leaving the thermostat. The other group heads in the direction of the heat pump which is located outside the house. Assuming those are the destinations of these wires the following is a list of the connections made by the 6 wire nuts.

Wire nut

  1. C on controller to heat pump

  2. W on thermostat to heat pump

  3. G on controller to G on the thermostat

  4. R on controller to RC on the thermostat and to heat pump

  5. Y1 on controller to Y on the thermostat and to heat pump

  6. W1 on controller to W2 on the thermostat and to heat pump

W2 on the controller is not connected to anything

There is a jumper on the thermostat from RC to C

My concern are that the Wyze app will not take into account the connections that split in two directions and tell me where to place the C-wire connector relative to the splits. I did not see that situation mentioned in the Wyze videos. For wire nuts 4, 5, and 6 do I keep the wires going to the heat pump and if I do, where do I connect them before or after the C-wire connector?


Thermostat is a Honeywell TH5220D
Het pump is a Rheem RP1542AJ1NA

Look at your old thermostat. use the bottom labels to define your wires. Your “W” wire is an O/B wire. Your "W2 wire is an Aux/E wire. The only wires going to your thermostat that need to be attached to the C adapter terminal are the Y, G, W and R wires.

Thanks, that makes things clearer. My thermostat connections are
W2 white
G green
W blue
Y yellow
RC red
there is a jumper from RC to R

On your drawing the thermostat connections are Y, W, Rc, C, and O/B. Am I correct that your C is my G, my W2 is your W, and your O/B is my W?

I unexpectedly have to go out of town for about 10 days so I won’t have a chance to try to install it until then. I’ll report back when I do.

Sorry I made a mistake. Should have been.

On your drawing the thermostat connections are Y, W, Rc, C, and O/B. Am I correct that your C is my G, your W is my W2, and your O/B is my W?

Yes, when you use the C adapter, you connect the old G wire to C. Your blue “W” wire is an O/B wire.
Your white W2 wire is an aux (electric) heating wire, which wyze will have you connect to W1.

Got it, thanks again.

Speadie, thanks for all the help you provide to the community. Before I begin the installation I want to be as sure as possible it will go well because working on the air handler wiring in a confined space is difficult. I read the “Wyze Thermostat with Heat Pump” thread and it seems some people have had enough issues with heating that they decide to reinstall their original thermostats. I want to avoid that.

Looking at my configuration and keeping in mind my location is the Tampa, Florida area will I encounter any of these problems and does my location change how I should wire the system?

Your old thermostat doesn’t have an outdoor temperature sensor, so it should be using similar logic to what the wyze uses. The people that will see the most negative impact from using a wyze instead of their normal thermostat will be those that currently use an outdoor temperature sensor and heat strips. The wyze seems to be defaulting to more aggressive heat strip usage, which increases comfort, at the cost of higher heating bills.

You should not need to make any changes on the air handler side of the wiring after the C adapter is installed unless you decide to switch thermostats. If you wanted to move the heat strips to emergency in the future, you would do that from the thermostat side of the wiring.

Thanks for the information. Did the wiring at the air handler and installed the thermostat today. Went well with two issues.

  1. When doing the testing, H1 did not produce and hot air. H2 did and the cooling worked. Should H1 produce heat?

  2. The app keeps showing the thermostat as not connected

Sorry posted before I finished. App says thermostat as offline but if I play with the setting I can get it to show connected for while and then it repeats. I am checking the " Thermostat always offline" thread for a solution.

Should have been H1 did not produce any hot air.

Heating source 1 should be the heat pump. Depending on outdoor ambient temperature, it may not produce much in the way of heat. There will also be a delay in switching from heating to cooling mode. Did you verify that it was running the outdoor condenser unit during the test in both heating and cooling modes?

I tried deleting the thermostat from the Wyze app and doing a factory reset to fix the connectivity problem. When I go add it back to the app I get a wiring error message see below. My connections at the thermostat are

Rc red wire

Y1 yellow wire

O/B Blue wire

C green wire

W1 white wire

Any help would be appreciated