Wyze thermostat lost FAN control option

I agree as well that @Cluster needs to provide more information about the situation. What he has going on and the information he has provided doesn’t make much sense.

First thing we need to know is if the color of the wire at the furnace board matches the color of the wire at the thermostat. If green at furnace board is green at thermostat then he has his G wire and C wire mixed up and is currently using the G wire as a C wire which is why his thermostat works but has no fan control.

Then we can see he has a wire on the C terminal at the board but it’s a brown wire that appears to be for the A/C system and it doesn’t run to the thermostat. Then he has a green wire that is on the board G terminal and then at the thermostat there also is a green wire, if this is the same wire that would mean the green wire is actually the G wire on the furnace board but is improperly labeled as a C wire behind the thermostat.

Thermostat wiring comes in 18 gauge by 3 wires, 5 wires, 7 wires etc. but they don’t come in 4 wire stands. So the fact that he has 4 wires behind thermostat says there should be another wire somewhere (which can be the C wire) If it was me I would ensure that the wire color at the furnace matches the wire color at the thermostat. Let’s assume that the colors match. If they do then I would re label the green wire as G and hook it to the G terminal on thermostat. Then I would take that 5th wire that should be somewhere and I would hook that to the C terminal on both ends and the thermostat will be wired and function properly with manual fan control. This would be the proper way if you already have 5 wires.

The other way to make it right would be to install the C wire adapter. Which will allow the thermostat to work as intended with manual fan control as well. My only issue with this is that he should have 5 wires which means he should have no problem adding a C wire and should not need the C wire adapter. The adapter is really for only if you don’t have a C wire and with a 5th wire not being used somewhere he could easily set it up to be the C wire.

At this point it’s speculation without @Cluster chiming in. I mentioned early on about the adapter and he did not say he did not have it installed.

Just because his picture doesn’t show the adapter doesn’t necessarily mean it’s not installed.

Again, this back and forth is pointless until we get clarification.

That’s exactly what it means. If the adapter was installed you would see it. It only gets installed in one place and that place is visible in the photos. The only way It could be installed is if it was done after the photos were posted. And if that was the case then it would be all speculation unless he actually says that he tried installing it.

Going based on the information and photos @Cluster has provided so far there is no way the C wire adapter is installed.

You do not know (nor do I) if he even posted the correct picture. He could have have mistakenly posted a pre install picture. His picture means nothing without clarification. I’m done with this pointless argument until the OP responds.

1 Like

The picture that was attached previously of downstairs furnace was before I placed the S wire, I am sorry for this confusion.

Please see the current situation, when the fan is not working.

The unit with thermostat never had any G wire sticking out. I only have 4 wires coming out of the wall (all bundled up in black insulation tape, but G is not one of them). Before wyze thermostat I had Honeywell and only used 4 available wires. When the fan worked before (for wyze), somehow the lack of G wire was not an issue and fan control function was working though the app and through the thermostat unit.

Is it possible that I can switch the G wire downstairs to the C wire terminal, and maybe that will make the fan work?

Thank you all so much for your ideas and helpful tips!

Hi @speadie , I tried doing it the right way (With the wires and pins, the way you described), but when I put the thermostat back to the mounting plate, there was no power to it. So I took it back to the “wrong” configuration (as the photo showed at the beginning), and the digital part of thermostat was working again.

To clarify, in this image, all the wires that are connected to the C adapter are coming from one of those thermostat wire bundles, correct? The other one with red and white going directly to the furnace board is coming from the other bundle? When you were setting up your wyze, did you tell it you were using a C adapter? If you do a reset, you need to tell it that you have the following wires in order for it to work properly: G Y Rc W. Do not tell it that the wire you have labeled as C is C or it will not know you have a C adapter and it will not work properly.

2 Likes

I got lucky, the furnace had all the wires but the C WIRE wasn’t connected at the furnace, so just had to connect it, after I figured out how to get the door off.

IT WORKED!

I “lied” to wyze app and told it I that have the following wires Rc, Y, W and G (instead of C) and now the fan works!

So although my panel on thermostat has C wire in the socket for C wire, I selected “G wire” during the “add new” thermostat, and everything works well now.

Thank you everyone on wonderful support and help!

1 Like

This worked for me, i changed the C wire setting to G wire in the app when adding device.

RE: if you reset it and told it that you have a C wire and not a G wire, then it doesn’t know you have a C wire adapter hooked up and will not allow you to control the fan.

Just worked for me as well. I hate this thermostat. Just sayin’