All of our thermostats are designed to work with 24VAC HVAC systems. If your HVAC system works with 120/240VAC (like baseboard heating), the ecobee is not compatible out of the box.
It's possible that you can re-wire your equipment to make the ecobee compatible by installing load relays with 24VAC control coils.
CAUTION: We highly recommend contacting a licensed contractor when dealing with line voltage equipment. Our Support team is unable to assist in these situations.