How do I wire ecobee3?

Asked By: Eiharne Merediz | Last Updated: 14th May, 2020
Category: home and garden smart home
4/5 (179 Views . 21 Votes)
How to Install an ecobee3 Smart Thermostat 73
  1. Step 1: Kill the Power to your HVAC.
  2. Step 2: Understand A Little About Thermostat Wiring.
  3. Step 3: Remove Your Old Thermostat.
  4. Step 4: Install the ecobee Power Extender Kit (PEK)
  5. Step 4-and-a-Half: Connect the Unused “C” Wire to your HVAC Control Board.

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Then, how many wires does the ecobee need?

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, depending on your application. Note: You will not be able to install the Power Extender Kit (PEK) with heat-only 2-wire systems.

Also Know, does the Ecobee thermostat have a battery? The Ecobee comes with one wireless sensor, which is powered by a CR2032 coin-cell battery; the company says it should last about 4 years. When the battery runs low, you'll receive an alert.

Also Know, does the ecobee3 need AC wire?

Your ecobee3 does not need them. Some thermostats do not have a C-wire. The C-wire is used to reliably provide power to the thermostat. In this case, the PEK can use the existing wires to power your thermostat.

How do I know what wire to get for my thermostat?

Here are common uses for wire colors:

  1. Blue or Black – C – Common wire, may be unused by your existing thermostat.
  2. Red – R – 24VAC power from the furnace's transformer.
  3. Red – Rc – 24VAC (dedicated to heat call)
  4. Red – Rc – 24VAC (dedicated to cooling call)
  5. Green – G – Fan.
  6. White – W – Heat.
  7. Yellow – Y – Air conditioner.

31 Related Question Answers Found

What color is AC wire?

Y wire (yellow, for air conditioning). W wire (white, for heat). C wire (blue or black, common for 24-volt power to the thermostat).

How do I install a smart thermostat without C wire?

To add a C-wire to your furnace, follow these steps:
  1. Turn off the breaker for the furnace.
  2. Remove the access panel and locate the wires that connect to the thermostat.
  3. Disconnect the thermostat wire from the G terminal.
  4. Note: If you have both central heat and air, then you'll need to make a jumper using an 18 AWG wire.

How does add a wire work?

The Venstar Add-a-wire and ecobee's Power Extender Kit somehow multiplex two of your existing thermostat wires (e.g. the ones that switch on your heat or fan) into one. That frees up one wire so that you can use it for constant power.

What is AC wire?

The c wire is an extra wire that can be used to provide a return path for continuous 24V power for any application. It's normally used to provide a return path to power the thermostat. The “c” stands for common. It is often labeled as “c” on thermostat backplates.

Can I install ecobee without C wire?


Even though it comes with an adapter for missing c-wires, ecobee is what we'd pick even for systems with a c-wire. If you've got a 24v HVAC system but no C-wire, check out the ecobee product line. Every ecobee ships with an adapter that you can install yourself at your furnace to make up for a missing C-wire.

What is a fast stat?

The FAST-STAT Common Maker Thermostat Wire Extender eliminates the need to install new cables when upgrading old thermostats to newer Wi-Fi thermostats. The Common Maker uses existing cable to add a "C" connection in a Wi-Fi thermostat allowing for 24 volt power source to be added.

What is a common wire HVAC?

In most cases, Google Nest thermostats can charge their built-in battery using your system's heating and cooling wires. A common wire is simply a wire that's dedicated to delivering constant power to your thermostat. Unlike the other wires connected to your thermostat it doesn't control heating or cooling functions.

What's the difference between ecobee3 and ecobee3 Lite?

The Differences Between Ecobee3 and Ecobee3 Lite. The Ecobee3 Lite does not support humidifiers, dehumidifiers, or ventilators while the Ecobee3 does. The Lite does not come with room sensors. The Ecobee3 comes with up to 3 room sensors depending on the size kit you buy.

How do you know if you have C wire?

It is easy to see if you already have a c-wire connected to your system. Simply remove your current thermostat face from its baseplate and look for the terminal labeled with the letter “c.” If this terminal has a wire attached to it, you have an active “c-wire.”

Where do you connect the C wire on a boiler?


To get a C wire to one or more of the thermostats, you'll simply run a wire from the other side of the transformer on the wall. The original wire from the transformer should be connected to the R terminal on the thermostat, while the new C wire should be connected to the C terminal on the new thermostat.

Where does e wire go on ecobee4?

The E wire normally connects to the ecobee's W1 terminal.

Which is better nest or ecobee?

Ecobee is more efficient than Nest at knowing if you're home or away because it has a motion sensor on the base and uses additional SmartSensors to detect motion and temperature. One room sensor is included with Ecobee SmartThermostat (none with Ecobee3 Lite), and you can add up to 32 SmartSensors to any Ecobee system.

What is the fastest way to wire a stat?

Connect the receiver module's yellow wire to the Y terminal. Connect the receiver module's red wire to the R terminal. Connect the receiver module's green wire to the G terminal. Connect the receiver module's black wire to the C terminal.

Does ecobee work without electricity?


To quickly answer your question, no ecobee does not use power stealing as a source of power. Here's why: Power stealing is a way of powering a thermostat using the circuits that turn on and off your HVAC system, rather than using a dedicated power wire or a Common wire (referred to as a C-wire).

Do all smart thermostats require AC wire?

A C-wire or common wire is a power supply that is required for your smart thermostat to work properly. Unfortunately, most of the older thermostat models didn't require one and that is the reason why many homes do not have a C-wire installed. Almost all WiFi thermostat models require a common wire.

What is RC wire on thermostat?

If the air conditioning thermostat has one transformer to power both the heating and cooling system, then the wire from the transformer goes directly to the RC terminal and is called the RC wire. This wire is also known as the RH wire.