Warning: Any work with high voltage equipment can be dangerous or even fatal. It should be performed by a qualified electrician. Please ensure that you comply with local electrical codes and regulations. Improper installation can lead to device failure and even cause a fire. Damage to thermostat due to improper installation is not covered under warranty.
The amount of wires connected to the existing thermostat is not an indicator of your compatibility for Mysa. Be sure to look in the gang box, your existing thermostat wiring does not necessarily indicate how many wires are in your gang box.
As you can see in the picture below, there are only two wires connected to the existing thermostat, but there is a third one in the gang box. This scenario is compatible with Mysa.
Before you install Mysa Thermostats, you should use our online compatibility checker. This will let you quickly see if your heating system will work with Mysa. If you're still unsure whether or not your home is compatible with Mysa, email your photos to us at firstname.lastname@example.org.
Please ensure you turn off the power of the circuit breaker controlling your existing thermostat and take all necessary safety precautions when checking the wiring.