Thermostat won't power on

I have a Taco ZVC404-4 controller that was installed last year connected to my boiler for heat in 3 zones. Zone 1 upstairs heat, Zone 2 downstairs heat and Zone 4 (priority) for sidearm hot water heater. I’m in Alaska so no cooking needed.

The current Tstats are wired R & W only with the C on the Taco not used. I setup the Wyze to test out and I have connected it to my upstairs Zone 1. The Blue and Green wires running to the Tstats are not connected so I connected the Blue to the C on the Taco controller for Zone 1. I then wired everything to the thermostat as instructed: in the Wyze app, R to Rc, W to W1, and C to C. When I connect the Wyze thermostat it doesn’t power up at all. When I connect the old honeywell Tstat everything works (battery powered) and triggers the zone controls as expected.

Am I missing something?What are some troubleshooting steps I should be trying to eliminate any possible issues before I declared the new Wyze Tstat “dead on arrival”?

I can post pictures here over I figure out how to do so

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Welcome back @majortomm!
It sounds like everything is wired up properly. Could you upload some pictures of your control board and thermostat?
To upload photos chose the upload icon when you are posting or replying.

Thank you @Brlepage for the instructions on asking images! I have attached a pic of the control board and the Wyze Tstat wiring below.


Using a multimeter set to AC volts, test between R and C to make sure you have at least 25 V

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