The existing Ecobee set up takes advantage of the PEK because I do think there are only four or 5 wires likely with the thermostat to your furnace but I'm able to relatively very easily include more wires if required to get two stages (thermostat is sort of right previously https://elliottzims.thezenweb.com/indicators-on-copyright-for-weight-loss-you-should-know-73884184