If you are finding that your heat is not running, check the physical Sensi thermostat on the wall. Ensure that the Wifi symbol is present in the top left corner, and does not show an "X". If your Sensi is not connected to Wi-Fi, Ecovent will not be able to adjust it to ensure your comfort settings are met. Follow these steps to reconnect your Sensi to Wi-Fi
If your Sensi is connected to the Wi-Fi and the heat is not running, check that the set point is above the current room temp:
If the set point is below the current temperature, Ecovent has determined that your heat should not be running as a result of your room settings. You can raise your room temps in the Ecovent app and shortly after Ecovent will adjust your Sensi thermostat.
If the set point is above the current room temperature, use this guide from Sensi to determine if your HVAC is set up properly and configured for your heat source.