I have a traditional cold start boiler with a 2 wire system. I do have one internet thermostat, but it's a beast, ethernet cable, big module on the boiler, etc. and a hideous outdated app and website, so I'd like to go wi-fi and put "nest like" tstats throughout (I have 3 zones). I've heard that Nest tstats can "rob" power from the boiler (electricity) for charging its battery, and that this "robbing" can interfere with the firing of the boiler from time to time. I believe my electrician says we can fix this by running a separate "c" or "power" wire, which adds a little to the labor but not too onerous.
Does anyone know of some other alternative "simpler" solutions with other WiFi thermostats?