Installation Overview

Last updated: October 23, 2026

Most installations take 15 to 20 minutes. This article gives the full procedure, from the box to pairing with the Mysa app.

Before you start

Warning: Installing this product involves handling high voltage wiring. To avoid personal injury, or death, turn off your circuit breakers and follow the proper safety precautions before proceeding.

Mysa for Electric Baseboard Heaters operates on 120/208/240 VAC. Turn off the power before completing any electrical installation. If you are unsure that the power to your heaters is off, stop work and call an electrician.

Some regions require an electrician to install a line-voltage thermostat. Check your local code.

Tip: The Mysa app gives step-by-step installation instructions. Before you start, do these steps:

  1. Download the free Mysa app from the App Store (iOS) or Google Play (Android).

  2. Create your Mysa account.

  3. Have your Wi-Fi network name and password ready.

Use the Mysa Compatibility Checker to make sure that your system works with Mysa for Electric Baseboard Heaters.

What you need

  • Phillips screwdriver

  • Voltage tester (strongly recommended)

  • Smartphone with the Mysa app

  • Wire stripper (optional)

  • Pliers (optional)

Installation procedure

1. Turn off the power

  1. Turn off the circuit breaker for your heater.

  2. Use a voltage tester at the thermostat wires to make sure that the power is off. We strongly recommend a voltage tester. It is the only reliable proof that the power is off.

If you do not have a voltage tester, do these steps:

  • Dial thermostat: Turn the thermostat all the way up. Wait 5 to 10 minutes. Put your hand on the heater and make sure that no heat comes from it. If you have more than one heater, do this check on each heater.

  • Digital thermostat: Make sure that the display is off.

A cold heater alone is not proof that the power is off.

If you do not know which breaker controls your heater, turn off the main breaker at your electrical panel. Do this in daylight.

If you are unsure that the power to your heaters is off, stop work and call an electrician.

Tip: If you install more than one thermostat, install one thermostat at a time.

2. Follow the installation guide in the Mysa app

The Mysa app has a wiring guide for your system. It covers dozens of different wiring configurations. This guide is the best way to install your thermostat correctly.

You can also use the step-by-step installation guide.

Open the Mysa app and start the installation. The app gives you instructions to do these steps:

  1. Identify your wiring.

  2. Remove your old thermostat.

  3. Connect the wires one at a time. Connect each wire from the old thermostat to the correct Mysa wire lead.

  4. Install Mysa on the wall and pair it.

Before you disconnect a wire, take a photo of your wiring.

Count the wires in your gang box. You need 4 wires: two cables with two wires in each cable, not counting the ground wire. One cable brings power in. One cable goes out to the heater. If your gang box has more wires, the step-by-step guide in the Mysa app and at getmysa.com/baseboard covers that.

If you see only 2 wires, look in the gang box for extra wires with wire nuts on their ends.

3. General wiring reference

The guide in the Mysa app gives instructions for your wiring. This is a general reference. Connect each Mysa lead to the house wire by its function, not by its colour.

240 V system:

  • L1 lead: the line wire (L1) from the breaker.

  • L2/N lead: the second wire (L2) from the breaker, joined with the L2 wire that goes to the heater.

  • Load lead: the wire that goes to the heater.

120 V system:

  • L1 lead: only the line wire (L) from the breaker.

  • L2/N lead: the neutral wire (N) from the breaker, joined with the neutral wire that goes to the heater.

  • Load lead: the wire that goes to the heater.

Use the wire nuts that come with Mysa. Do not use the old wire nuts again. Push the wires fully into each wire nut. Pull each wire gently to make sure that it is tight.

4. Install Mysa and turn on the power

  1. Attach the Mysa base plate to the gang box with the mounting screws that come with Mysa.

  2. Put the front plate on Mysa. It glides into place.

  3. Tighten the screw on the bottom of the front plate. Do not overtighten the screw.

  4. Turn on the circuit breaker.

The display comes on. When Mysa is ready, Gen3, V2 and Lite display the Bluetooth pairing symbol. Mysa for Electric Baseboard Heaters V1 displays a Wi-Fi symbol.

5. Pair Mysa

Continue with the guide in the Mysa app to do these steps:

  1. Connect to the thermostat with Bluetooth.

  2. Connect to your 2.4 GHz Wi-Fi network.

  3. Select your heater type: Baseboard, Fan-forced or Radiant.

  4. Give your thermostat a name.

Installation problems

After you connect the wires, these problems can occur:

  • The thermostat does not come on.

  • The heat does not stop.

  • There is no heat.

  • A GFCI trips.

  • An error code is on the display.

To solve these problems, read Installation & Wiring Troubleshooting.

Installation videos

For the steps for your wiring, use the step-by-step installation guide.

User manuals

For Gen3, use the step-by-step installation guide.

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