Wyze Thermostat not getting power

I’m going to try to make this both as brief and thorough as possible. Long story short, I’ve got a Trane heat pump with the following wires:

R (red, jumped with Rc)
O (orange)
Y (yellow)
Y2 (brown)
W1 (white)
G (green)
X2 (black)
B (blue)

I attempted this configuration on my Wyze thermostat and didn’t get power, only a consistent clicking every few seconds:

R to Rc
O to O/B
Y to Y1
Y2 to Y2
W1 to W1
G to G
X2 to W2 / * / C (tried all three)
B to C (left this off when trying X2 on C)

I tested the voltage from the wiring and got 21V from Red to Blue. The configuration the app suggested was to use put X2 (black) to C. I tested the voltage from Red to Black, and it was 27V; however, using neither one of these seemed to give it power. I did notice that using the black wire for C produced a series of faster, unsteady clicks as opposed to the slower, even clicks when using blue, so I’m not sure if that’s significant.

I’ve since put my old thermostat back on as this is a horrible time of year to attempt replacing it, but our old Trane one barely functions anymore as most of the touchscreen is dead (can’t change cool / heat / off, can only turn the temperature down, not up)…so basically, it’s better than nothing, but not by much. Please help!

Welcome to the community @rpewing . Sorry to hear you are having an issue.

In order for the T-Stat to work you have to utilize the C Wire as that is where it gets the power for it to come on. If possible, can you take a picture of your HVAC unit where the Control board is so we can see how the wires are connected to it?

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There is a Trane heat pump configuration that uses both of the B and O terminals to control its reversing valve, Unfortunately, the wyze thermostat (and indeed, most smart thermostats by any maker) is not compatible with this configuration.

Like spamoni said, I’d need pictures of the air handler side and any relevant schematic drawings in order to determine if your unit is one of those, or if it can be wired in such a way to have the wyze thermostat control it properly (and get power).

Also what is the model of your old thermostat?