ecobee thermostats require a C (common) wire to energy on. If the current thermoregulator makes use of just two cables (R and W, or T and T), you can find an installation that is few available, according to the application.
Before starting out, take note the annotated following:
You'll not manage to install the Power Extender Kit (PEK) with heat-only 2-wire systems. The PEK can just only be utilized on furnace or temperature pump systems which do not have C cable вЂ” it is because the PEK calls for R (energy), G (fan), and Y (compressor) cables to work, and these 2-wire heat-only systems do not need these G and Y cables
To find out compatibility, you shall have to access both the wiring at your thermoregulator along with the wiring at your heat in which the thermoregulator wiring comes to an end.
You can reach out to ecobee support for guidance, or hire a technician to aid in installation if you are not comfortable doing so