From Nest to Wyze Thermostat: two wire no worky

Hi Wyze team, I’ve had a Nest thermostat working on a heat only, two wire config (R + W) with an old furnace, for the last two years. It seems I will need to order a two wire power adapter and move to a 3 or 4 wire config to get my Wyze thermostat working…?

How do you wire the R+W to a new config, with C + Rc for power and …?? for the previous R+W wires? Previously, I got an unpowered o/off heat relay config (for gas fireplace) working on the C / RC for power plus Rh / W1 for heat. However this home furnace has a POWERED relay (which the Nest thermostat was able to get power from). What wires to use here?

Thanks so much for the help. Wyze team, please, better docs for those who have to transition from something that works to …??? with your setup. If you have an existing thermostat as I do a lot of the time your setup wizard totally dead ends, though it is possible to use your thermostat. Having a better wizard - and perhaps a $10 power supply as part of your offering - would strengthen this product a lot.

Also , it would have been a good design goal to meet the same needs as the existing companies out there (eg Nest) and to do so at a lower cost.

Thanks Everyone! All that said, still loving affordable and generally usable Wyze products.

All heat systems have power running through the thermostat, It’s how they work. Thermostats are just temperature controlled switches. when it wants heating, it closes the contacts and connects the wires together in specific fashion. with a 2 wire system, it just connects the only 2 wires it has coming in.

Your option is to either run a third wire to provide a common path back to the transformer, or to connect a 24VAC wall adapter to Rc and C and connect your existing wires to Rh and W.

The reason the nest can use only 2 wires is because it has an internal battery that is charged by “stealing” power from your system when it is running. They wyze does not contain a battery and does not steal power, thus preventing the wyze causing the same issues that the nest can cause - relay chatter and premature furnace relay failure to name a couple,

I had similar problem. Ran third wire from transformer to thermostat. Be sure to connect to transformer pole that does NOT have the red wire to thermostat. This will be the common wire.

The big issue is frequently running the wire. If you have existing wires running from thermostat to attic or basement, you can use existing wires to pull a string to basement or attic then pull back to thermostat existing wires plus third wire. That works as long as some idiot contractor didn’t fasten wires to stud or pulled horizontally through several studs. Easy enough to try if you have 2 people.