Zen Thermostat Installation Guide

Conditions of use

By proceeding you agree to the following conditions of use for ZEN Thermostat™ and this website:

You can review all of these by clicking on the links above.

Inside the box

Wall mount, Main Display, 4 x AA batteries, Wire label stickers,
Blanking Plate, Wall Plugs, Wall screws,

What you need

Drill and 1/4in (6mm) drill bit
Ball point pen or pencil
Optional: Hammer, level

1. Turn off the HVAC power

Turn off the power to your HVAC from the breaker box or HVAC power switch.

Make sure the power is off by adjusting the setpoint on your old thermostat and check that the HVAC does not turn on.

Turn off the HVAC power

2. Remove cover from old unit and take a picture

Remove your thermostat’s cover to expose the wiring.

Remove your thermostat’s cover to expose the wiring.

Make sure to take a picture of the wiring with all the wires clearly visible and the labels on the thermostat terminals readable.

3. Safety check

Is your system labeled 120V-240V?
If so, your system is high voltage and is NOT compatible with ZEN.
If you’re unsure, please contact your home automation provider or HVAC installer.

Warning! Extra Low Voltage only. Do not connect to mains voltages.

Do you see thick wires with wire-nuts?
If you do, your system is high voltage and is NOT compatible with ZEN.
If you're unsure, please contact your home automation provider or HVAC installer.

Thick wires

4. Select your existing wires

Watch Video ▶

Check the boxes below that correspond with the labels on the wire terminals of your old thermostat. You can disregard any links or jumper wires. Do not identify your wires based on colour.

Why do you need this?

The way your old thermostat is wired is one of the best guides for how to wire up the Zen thermostat. Correctly identifying the wires that exist ensures that all the functions of your heating and cooling system will be able to be controlled by the Zen thermostat. If you are unsure or your wires terminals are unlabelled please contact your home automation provider or HVAC installer.

We require more information to confirm that Zen thermostat supports the wiring combination you have selected. Please check that you have identified the correct wires, or send us an image of your wiring to support@zenthermostat.com and we'll get back to you with further guidance.

5. Label your existing wires

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TIP: Attach the labels roughly 1in (25mm) away from the end of the wire to make reinsertion easier.

Why do you need this?

Labelling your wires before you remove your old thermostat saves time when installing the Zen thermostat and will be useful if you decide to change or upgrade your heating or cooling system in the future.

6. Disconnect your existing wires

Watch Video ▶

WARNING: Do not allow wires to fall into wall cavity.

WARNING: Ensure that any wires that will not be reconnected are properly insulated.

Disconnect your existing wires

TIP: Check wires have between 8-10mm exposed core.

Check wires have between 5/16 - 3/8in (8-10mm) exposed core.

7. Remove the old unit

Remove the old unit

8. Mark the mounting hole positions

TIP: Use a level to help align the wall plate.
If your previous thermostat was larger, you may chose to use the blanking plate to cover any unsightly areas.

Mark the mounting hole positions

9. Drill the mounting holes

Use a 1/4in (6mm) drill bit if using the wall plugs.
Ensure that the wires are kept out of the way when drilling.

Drill the mounting holes

10. Attach the wall mount

Attach the wall mount

11. System Types

What type of heating do you have?

Why does heating type matter?

Zen thermostat will be configured to operate in the safest and most efficient manner, which is different for different types of heating systems.

12. Review your wiring diagram & connect your wires

Watch Video ▶

Simply push the wires into the corresponding holes as shown in the image below.

The white Release Button can be pressed with a pen to make insertion easier or release the wire. You may need to twist the exposed core to help the wires into the holes.

Wire hole, Release button

After your wires are connected, make sure they are secure by lightly pulling on them. Ensure the wires are then pushed back and flush with the wall-plate.

13. Check your links

L1 and L2 both removed L2 present, L1 removed L1 and L2 both present L1 present, L2 removed

14. Powering the unit

Option 1

Insert batteries

Option 2

15. Connect with your home automation system

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The network button

15.16. Entering your system code

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Your system code ensures that the thermostat is configured correctly for your system. Press the CONFIG button once to enter configuration mode.

Entering your system code

Your system code

What does this code mean?

This code tells the Zen Thermostat what wires you have connected and what type of heating and cooling system you have.

Center touch to begin configuration.

The system code above has been generated based on your specific system configuration.

Touch up or down to find your system code.

Center touch to select. The code will flash to confirm selection.

16.17. About your system configuration

Your system code tells Zen everything it needs to correctly operate your heating and cooling system.

Your Heating Type:

Your Cooling Type:

Your system has separate fan control

Your system has emergency heating

Your system DOES NOT use a reversing valve to select between heat and cool

Your system COOLS when the reversing valve is turned on.

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17.18. Turn on HVAC power

18.19. Mount the display

Mount the display

19.20. Status Check

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After mounting the display do a quick check of the following to ensure that the thermostat is properly controlling your HVAC system

  • Change the temperature mode to heat and adjust temperature up by 5°
  • Allow the system a few minutes to turn on and check to make sure warn air is coming out of the vents
  • Repeat step A. and B. for cool mode as well.

Have any further questions? Check out our FAQ

Zen screen with symbols
Installation Complete

Congratulations you have now completed your ZEN installation and setup.

Review the quick start guide in the packaging for tips on using ZEN or watch this video:

Watch Video ▶

Next, please return to the XFINITY Home App to pair the device and setup EcoSaver.