emerson sensi wi-fi smart thermostat for smart home, diy, works with alexa, energy star certified, st55 emerson thermostats style:diy with homekit from across the room or across the country, your sensi wi-fi thermostat makes it easy to remotely control and schedule your home comfort - anytime. anywhere. designed to work with the wires you already have, sensi thermostat does not require a common wire (c-wire) for most installations, so it is compatible with the hvac equipment in many homes* in u.s. & canada. a c-wire is required for heat-only, cool-only and heat pump (without aux) systems, and for use with apple homekit. check to make sure it will work for you at sensicomfort.com/compatibility. the intuitive app walks you through each step of installation with custom configured instructions, removing all the frustration and guesswork from the installation process so you can be up and running in no time, no experience required. put your comfort on your terms using location-based temperature control with geofencing or creating custom heating and cooling schedules with the flexible 7-day scheduling option. both energy saving features help to reduce your hvac related energy costs so you can save money without compromising your comfort. plus, sensi integrates directly with amazon alexa, apple homekit and wink home automation platforms, and works with google home and google assistant via the free wink app. connect to amazon alexa to control your home temperature with simple voice commands, or just ask siri to set, raise or lower your home temperature when using sensi with apple homekit. what’s more, sensi wi-fi thermostat has been named the ‘best value’ smart thermostat of 2017 by usa today’s reviewed.com. if you need anything, we’re here to help. visit sensicomfort.com/support for around-the-clock access to support articles, instructional downloads and comprehensive support videos. our highly-trained sensi support team can be reached at support@sensicomfort.com or seven days a week. *does not work with electric baseboard heat and some other systems.<br /><br /> - works with alexa for voice