I am trying to install a new Ecobee3 wi-fi thermostat to replace my old mercury thermostat. When I pull off old thermostat there are only 4 wires (red, white, yellow, green and a blue tied around). When I look at my furnace there are same 4 wires, plus two additional red and white wires (white is occupying com 24v and red is on Y terminal). Those two wires appear to be running outside to my A/C unit. I do have power extender kit that Ecobee supplies, but unsure which wire goes where or how to fix easily since there is no C wire running to thermostat.
thanks for your help.
]2
Connect Ecobee3 thermostat – no c wire but c terminal occupied
furnacethermostatthermostat-c-wire
Related Topic
- Wiring – I have older HVAC unit (heat pump) and looking for the C wire to hook up to Smart Thermostat
- Electrical – need to connect a c wire to the furnace/air conditioner
- New ecobee3 lite, have heat but no cool option
- Connect C wire for nest thermostat on a zoned HVAC system
- Connected C-Wire (previously unused) to thermostat, but still no power
Best Answer
Connect the blue wire from the thermostat cable, to the
Cterminal in the furnace. Then connect the blue with at the thermostat, to theCterminal of the new thermostat.