Best smart thermostat for my configuration...

marcl

I have a Taco heating system supplying three zones and a newly-installed York air handler and condenser for cooling (one zone for the entire house). I had an older Nest thermostat for heating only, and two old mercury thermostats for the other two heating zones. That thermostat was not compatible with split cooling/heatings systems, but the 3rd gen Nest I purchased kept giving me a no power error even when supplying a C wire. I plan to replace the three thermostats (1 for cooling/heating, 2 for heating only in the other heating zones), despite not needing to change the 2 heating only zones. I am doing that so that I can remotely manage those zones in the winter. Which thermostat ecosystem would you recommend for this? Note that I could not get the Nest to work and Google support first told me I needed a tech and when the tech couldn't figure it out, they said the system was not compatible. (The system is brand new, so I doubt it's a compatibility issue.)