Smart, really smart
The ecobee Smart Si intuitively understands when to turn on your heating or cooling equipment based on your home's unique energy profile and the weather outside, making sure you're comfortable at all times.
Lower your energy bills
ecobee Smart Si saves homeowners an average of 23% annually, paying for itself in energy savings. Learn how to save more.
Monitor and control your WiFi connected Smart Si anytime from anywhere, on your smartphone, tablet, or computer.
Buy with confidence
ecobee Smart Si is compatible with 95% of homes in North America and our Compatibility Checker ensures you make the smart choice. Each thermostat comes with a 3-year warranty and dependable technical support.
Before you purchase the Ecobee SmartSi Thermostat, please make sure that your heating and cooling system(s) are compatible. You can easily check your HVAC compatibility by using our Thermostat Buyer's Guide.
What’s a C-wire?
A c-wire (also referred to as a common wire) is a low voltage power wire that many modern thermostats require for their features to work. This Ecobee SmartSi Thermostat requires a c-wire to work.
Many older homes don’t have a c-wire because mercury and battery-powered thermostats didn’t require one. Therefore, it is important that you make sure that you have a c-wire and that your HVAC system is compatible with Ecobee's thermostat. To determine if you have a c-wire, please remove your old thermostat's cover plate. You should see several wire terminals labeled with letters. If a wire is connected to the “C” terminal, you have a c-wire.
If you do not have a c-wire on your existing thermostat, you maybe able to substitute an extra wire or the “G” wire for the c-wire. You can also hire an HVAC contractor to help you install the c-wire and the thermostat.
If you still have any questions regarding Ecobee SmartSi, please contact our customer support team.