Wyze Thermostat - No Power - Multiple Blue wires at Unit but none connected to the Therm block

Combined external Heat (Gas)/AC Unit - all-in-one.
(https://photos.app.goo.gl/ziq7tFnsj4eKmPg9A)

I have a C (Blue) wire present at the Thermostat:

Wired up the Thermostat per the instructions and all I’m getting is a clicking sound. At the unit that Blue wire is spliced to another Blue wire that disappears into a wiring bundle with at least two other Blue wires.

Near as I can tell the Blue wire from the Thermostat goes to a separate wiring block,
but I’m not sure where it goes from there or if I need the C-Wire adapter or how to wire it in. The Thermostat wire block doesn’t have a Blue attached to it.

Link to all the photos together:

I tried to post the images inline with the text for a better description/visual but as a new user I can only embed a single image and can only include two links???

Any assistance would be greatly appreciated…I’ve searched and searched but haven’t been able to find anything that matches.

Thanks in advance!

Do you have a picture of the transformer?
What’s the condition of this fuse:
image

Schematic and block diagram for your unit indicates that the blue wire should basically be directly connected to the common side of the transformer.


If the fuse is fine, you might have a weak transformer?

Thank you! I checked the fuse and it’s good.

Here is a pic of the transformer.

That’s the contactor. how about the left side of the enclosure?

Sorry! Here is a pic of the other side.

Everything looks good. I suppose it could be a loose, or damaged C wire. To eliminate this possibility you could use the C adapter.
To do that , you would connect it as follows:

and tell the wyze during setup that your “old thermostat” has the following wires:
Rc,
W
Y
G

Note that the green wire goes to G on the C adapter and C on the wyze in this configuration.

If that still doesn’t fix the problem, the transformer might just be underpowered, but as replacing that requires dealing with high voltage, it’s generally something you would want a technician to do.

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Thank you so very much for sharing your knowledge and expertise! It is greatly appreciated! I’ll give the C adapter a shot, hopefully this evening and will post my results.
Again, thank you!!!

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Well, still no joy. Is the next step to replace the transformer? Is there a way to test it to be certain it’s weak? I’m comfortable working with electricity.

Well, I was hoping that your transformer had a VA rating sticker on it, but it doesn’t. it looks like it’s probably a 40-50VA transformer, but I can’t be certain without a tag.

It takes 240VAC (primary) and converts it to 24VAC (secondary)

Generally I’d recommend going up 20-25VA for adding a smart thermostat if your transformer is weak. ex: if you have a 20, go up to a 40, if you have a 40, go up to a 60, if you have a 50, go up to a 75.

You might have a defective thermostat though. I don’t suppose you have a known working 24V transformer that you can test? If you hook up just the Rc and C terminals to a known working 24V transformer, the thermostat should at least power on. I’d do this test first before replacing the transformer.
If you don’t have a different transformer, you could try hooking up the thermostat directly at the furnace, just to see if it powers up there, without the resistance of the thin thermostat wire added in. even with a weak transformer, the thermostat should power up if you try to connect it directly to the furnace. If it doesn’t, you likely have a faulty thermostat or your fuse is blown.

Additionally, if you have a multimeter, you could test the red and blue wires at the thermostat mounting point in AC voltage sensing mode and see what voltage your thermostat is actually receiving (red and green if the C adapter is still hooked up on the other end) - It should be between 23.5 and 36 VAC - if it’s lower than 23.5 V, then you either have bad thermostat wires or a weak transformer.
Just don’t short the R and C wires together or you will need to replace that fuse on the furnace controller board.

Thank you again! Unfortunately, I do not have a known good transformer that I can swap out. I did put a meter on the Rc and C Wires at the thermostat and am only getting less than 3 Volts. As soon as I can, I’ll test the transformer at the outside unit for output… I found a tutorial online on how to do that