Sensi ST55 Smart Thermostat, Wi-Fi, Alexa

Control home comfort from nearly anywhere with the Sensi ST55 Smart Thermostat. Built around a familiar thermostat layout, it adds Wi-Fi connectivity and app-based control without requiring homeowners to adapt to an unfamiliar interface. The Sensi app provides guided installation and remote temperature management, while support for Alexa adds convenient voice control. ENERGY STAR certification and built-in energy monitoring tools help homeowners make informed decisions about heating and cooling use.

Connected Comfort and Flexible Scheduling

Connect the thermostat to a 2.4 GHz Wi-Fi network to manage temperature settings from a compatible mobile device. Create a 7-day programmable schedule or use geofencing to adjust comfort settings around household routines. Smart alerts can notify users when Sensi detects certain heating or cooling issues, while monthly energy usage information provides additional visibility into HVAC operation.

Broad HVAC Compatibility

The ST55 supports single-stage, multistage, and heat pump configurations, including systems using gas, oil, electric heat, conventional air conditioning, boilers, and radiant heat. Most conventional combined heating and cooling installations do not require a common wire. A common wire is required for heat-only, cool-only, and heat pump systems, so existing wiring should be checked before installation.

The traditional footprint helps cover the area occupied by many existing thermostats, reducing the need for wall patching or painting. On-screen humidity monitoring, keypad lockout, app-based controls, and smart home integration add useful connected features while keeping everyday temperature adjustment straightforward.