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.
Yes, you do need to turn off the power to install Mysa. This is essential to protect you during installation. Line voltage thermostats such as Mysa are connected to dangerous voltages.
Open your electrical panel and turn off the power at the circuit breaker controlling the thermostat you want to replace. For some older homes, it is not very clear which circuit breakers control which parts of the house. In this case, we recommend exercising more caution and turning off the main circuit breaker. Don't forget your flashlight!