Lennox S40 Smart Thermostat, Touchscreen Communicating, WiFi, Programmable, 3 Heat/2 Cool


Product Overview


Lennox S40 Smart Thermostat, Touchscreen, Communicating, WiFi, Programmable, 3 Heat/2 Cool 

The S40 Smart Thermostat recognizes and connects to all Lennox communicating products to automatically configure and control the heating/cooling system (based on user-specified settings) for the highest level of comfort, performance and efficiency. S40 Smart Thermostat also recognizes model and serial number information for Lennox digitally communicating products to simplify system setup. Learn more about the S40 Smart Thermostat below or visit the S40 resource hub for all your dealer needs.

  • Complement your home comfort system with our suite of technologically advanced accessories to more precisely and efficiently maintain the temperature and air quality in your home: Smart Room Sensor, Smart Air Quality Monitor and Wireless Extender 
  • Advanced digital controls in specific heating and cooling units and the PureAir™ S Air Purification System communicate information about various operating parameters to the thermostat to constantly maintain the most efficient operating conditions possible 
  • Additional conventional (non-communicating) indoor air quality comfort products (Healthy Climate® Humidifiers, Humiditrol® Enhanced Dehumidification Accessory, Healthy Climate® HRV/ERV Heat/Energy Recovery Ventilators, Fresh Air Damper, Healthy Climate® Germicidal Lights) can be added to the system for a complete total-comfort system 
  • Conventional HVAC systems (non-communicating) can be controlled by the S40 Smart Thermostat with the addition of the optional Equipment Interface Module (EIM) 
  • Optional Smart Zoning System (iHarmony®, for specific HVAC systems) allows whole-home zoning (up to 4 zones) with complete control from the S40 Smart Thermostat and individual In-Zone Thermostats 
  • A simple easy-to-use touchscreen allows complete system configuration. Scheduled maintenance alerts, system warnings and troubleshooting are also displayed on thermostat screen 
  • Up to four separate schedules are available plus Schedule IQ™ 
  • One-Touch Away Mode - a quick and easy way to set the cooling and heating setpoints while away 
  • Smart Away™ - Schedule IQ™ uses geo-fencing technology to determine when the homeowner is within a predetermined distance from the home to operate the system when leaving, away and arriving 
  • Weather-On-Demand - live up-to-date weather data and seven-day forecasts 
  • Easy to read 7 in. high-definition color display (measured diagonally) 
  • New Lennox Smart Technician app allows for quick and easy install of S40 Smart Thermostat and the new smart accessories 
  • Installer setup screens allow quick and simple system configuration without a manual 
  • Installer can also run tests on complete system or individual components for easy maintenance and troubleshooting 
  • Service Dashboard features online real-time monitoring of installed smart digitally enabled systems 
  • Uses 4-wire standard thermostat wiring. We highly recommend using 18 - 22AWG shielded thermostat cable for communications terminals (I+ and I-) which will help eliminate any noise interference. 

Note: The Lennox S40 Smart Thermostat with Equipment Interface Module (22X18) will work with most 24VAC furnaces, air conditioners, air handlers and heat pumps (up to 3 stages of heat and 2 stages of cooling), EXCEPT IT WILL NOT WORK with any brand of communicating HVAC equipment other than LENNOX®. 


Brand: Lennox
Catalog Number: 22V24
Model/Part NumberS40
Minimum Order Quantity: 0.0
Base Unit of Measure: Unit(S)
TypeCommunicating Touchscreen Smart Thermostat
Gross Weight: 1 LB
Core Product: No
TypeT: ouchscreen Smart Thermostat
Programs per Week: 7 Day
Changeover: Auto changeover
Wi-Fi Enabled: WiFi
Intelligent Recovery: Intelligent Recovery
Product Height4.438 Inch
Product Width: 7.063 Inch
Product Depth: 0.75 Inch
Stages: Universal 3 Heat/2 Cool

The S40 Smart Thermostat is a one-piece architecture display.   

*** Important Warranty Note*** 

10-year warranty valid on S40 Smart Thermostat in residential applications.  See warranty documents for details on how to file claim.  
Manuals are virtual.  Inside box you will find an Installer Quick Start Guide and a Homeowner Quick Start Guide.