ecobee thermostats require a C (popular) wire to power on. When your current thermostat utilizes just two cables (R and W, or T and T), you will find an installation that is few available, according to the application.
Prior to starting out, take note the annotated following:
You’ll not have the ability to install the Power Extender Kit (PEK) with heat-only 2-wire systems. The PEK can just only be properly used on furnace or temperature pump systems which do not have C wire вЂ” the reason being the PEK calls for R (energy), G (fan), and Y (compressor) cables to work, and these 2-wire systems that are heat-only not need these G and Y cables
To find out compatibility, you shall have to access both the wiring at your thermoregulator plus the wiring at your home heating where in actuality the thermoregulator wiring concludes.