The s40 lennox hvac thermostat does not have a specific website for login. the only way to control your s40 smart thermostat remotely is through the lennox smart thermostat mobile app. you can download this app from either the apple app store or google play store. once you have the app, you can create an account and add your thermostat to it. if you're having trouble logging in, you might want to try resetting your password. you can do this from the thermostat by going to menu > user account > email > forgot password > enter password and hit accept. you can also reset your password from the lennox smart thermostat app by tapping/clicking on the trouble logging in? button if you are signed out. if you're still having trouble, please reach out to lennox technical support at 1-800-453-6669 if you are a technician or 1-800-953-6669 if you are a homeowner.
For more information or a visual representation of steps please reference our user guide here
