Setup & Preferences The ecobee will guide you through accessory configuration during initial setup and you will be given the option of selecting a 2 wire or 1 wire accessory.
If you're lacking a C wire and have at least four wires at your thermostat to work with, the Power Extender Kit (PEK), included with your smart thermostat, can be installed at your furnace control board.
If you have a really old 2-wire system, one that does NOT have modern solid state controls, then Ecobee won't work right off the shelf, even with their 2-3 wire power conversion module. These heating plants predate the 1980s and use "dry contact" thermostats. You can make it work if you install a 24v isolation relay.
Am I compatible with ecobee? If you have a heat-only system, you may notice that your thermostat has three wires—R, G, and W. In this scenario, the Power Extender Kit (PEK) is not compatible. There are three options available to create a C wire and make the ecobee compatible.
This is a common problem when replacing a mechanical thermostat or a thermostat powered by batteries. These older thermostats require 4 wires, but newer more sophisticated thermostats require a 5th wire known as the Common wire to power the digital display.
Smart thermostats typically require a C-wire (common wire) for constant power. This is typically the fifth wire in a five-wire system. However, not all homes have this wire installed. In the video, Ross demonstrates a workaround for four-wire systems lacking a C-wire.
Enhanced Features: 5-wire thermostats are capable of supporting advanced functionalities like Wi-Fi connectivity, programmable schedules, and energy-saving modes.
ecobee thermostats require a C (common) wire to power on. If you only have two wires at your current thermostat, there are a few installation options available.
You can check the back of the ecobee by gently removing it from the back plate. Firmly grab the ecobee thermostat and gently pull straight away from the wall without twisting or turning. Under the barcode there will be a 12-digit code, you can differentiate the models based on the first 2 digits.
Multiple wires link the controller to your HVAC system. Each of them has a different function. They ensure the thermostat communicates properly with heating, cooling, and other components.
If you don't have a C wire, you'll need to use the Power Extender Kit (PEK) included to reliably power your ecobee.
A 2-wire thermostat is almost always for a system with heat but without air conditioning, controlled by a digital thermostat. The two wires are most often red for power and white for heat.
ecobee thermostats are designed to work with most 24-volt systems, even older ones. Take a look at your thermostat. If your system is high-voltage, the thermostat should be labeled with 120 V or 240 V or have L1/L2 labels and thick wire nuts. High-voltage systems like electric baseboard heaters are not compatible.
With dual-transformer systems you'll have two R wires—one from the cooling transformer (Rc) and one from the heating transformer (Rh). Learn how to install an ecobee thermostat in a dual-transformer system. If you don't have an Rh wire, Rc serves as both the cooling and heating power wire.
Rc and Rh: The red wire(s) are the power source for your thermostat. If your thermostat is dedicated to air conditioning only, it will have a red Rc wire. For heating and cooling systems, it will have a red Rc and a red Rh wire. Though both wires are red, they are not interchangeable.
Also known as the common wire, the C wire is what enables the continuous flow of 24V power that ecobee thermostats need to operate. To install an ecobee in an ecobee thermostat in a dual-transformer system, the C wire needs to be connected to the cooling system, not the heating system.
As of July 31, 2024, we're discontinuing support for two of our oldest Thermostat models: ecobee Smart Thermostat (Model #: EB-STAT-02, released 2009) ecobee Energy Management System (EMS) business thermostat (Model #: EB-EMS-02, released 2010)
Based on internal measurements the average lifespan of an ecobee thermostat is 12 years. “E-cycling” is the recycling process for electronics and means electronics are removed and processed safely to remove and reuse metals.
Smart Security's Arm/Disarm Assist feature works with Autopilot, which uses a combination of your phone location (geofencing), Wi-Fi connection, and ecobee sensor information to determine if you are home or away.
FOUR WIRES
This is a popular configuration for a battery-powered thermostat or a digital thermostat that solely regulates heat. The standard configuration consists of 24-volt hot (red), 24-volt common (blue), heat (white), and a fan (green).
Designed with input from professionals, the ecobee Smart Thermostat Lite is easy to install, straightforward to use, durable and hardwired for enhanced reliability, eliminating the need for charging or a secondary power source.
You need a "C" (common) adapter if you have a 4 wire setup, if you have a 5 wire setup then it is not needed. Many modern digital thermostats have the "C" wire adapter built-in and it is called a "Power stealing circuit" by many professionals.
US AC power circuit wiring color codes
The protective ground is green or green with yellow stripe. The neutral is white, the hot (live or active) single phase wires are black , and red in the case of a second active. Three-phase lines are red, black, and blue.