Lennox S40 (22V24) Smart Thermostat, Touchscreen, WiFi, Communicating System Control, Programmable, High Efficiency, Geo-Fencing, Remote Access, Wi-Fi and Alexa Enabled, Easy Installation
$358.53
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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.
To provide worry-free 10 year warranty against manufacturing defects or defects. To maintain warranty validity, it is necessary to hire a certified HVAC loader for proper installation. Failure to use a professional HVAC loader may render the warranty void. If the thermostat is not professionally installed, the item cannot be returned or returned. How to register for warranty, instruction included in the box.
It has a 7 inch high resolution color screen for easy readability. User-friendly touchscreen for easy system configuration and maintenance alerts. Using geographical fencing technology, multiple programs offer One-Touch Away Mode and Smart Away feature.
Compatible with 4-wire standard thermostat cables, use protected thermostat cable to prevent noise interference. Works with most 24VAC ovens, air conditioners, air conditioning processors and heat pump (up to 3-stage heat and 2 cooling stages) outside of the communication of HVAC equipment outside LENNOX.
Compatible with traditional HVAC systems with optional Equipment Interface Module (EIM) for control. The Smart Zoom System (iHarmony) allows the entire home improvement with full control from the S40 Smart Thermostat.
On-Demand Weather provides live weather data and seven day forecasts. Quickly set up and configure with the Lennox Smart app. Installer setup displays allow quick system configuration without manuals.
Test on the entire system or individual components for maintenance and troubleshooting. Service Panel allows real-time monitoring of installed smart systems.
Improve temperature and air quality control with advanced accessories such as Smart Room Sensor, Smart Air Quality Monitor and Wireless Expander. Taking insights from digital controls and through the PureAi S Air Purification System to maintain efficient working conditions.
4 reviews for Lennox S40 (22V24) Smart Thermostat, Touchscreen, WiFi, Communicating System Control, Programmable, High Efficiency, Geo-Fencing, Remote Access, Wi-Fi and Alexa Enabled, Easy Installation
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$358.53
Lovestospendmoney –
Worked great and easy setup.
Perfect replacement for my comfort sync black screen.I know I won’t get the warranty. But I couldn’t see spending that much money to have some rando put 4 wires into this new thermostat and push setup.It’s accurate. It has more features than my comfort sync. It’s wireless and app is seamless.Got it for 325. HUGE improvement since these go for 700-900 usually.I’m a happy guy in a cool house
EJ Honda –
Easy DIY swap for an existing Lennox iComfort 10f81 thermostat
After 12 years, my previous Lennox iComfort 10f81 WiFi thermostat started having screen issues, so I started digging into my options. So glad I found information indicating this S40 thermostat was a viable replacement (the older 10f81 thermostat is no longer manufactured and can only be purchased used, for about the same price or more than this new S40). This S40 is a huge step up in functionality, and the excellent Lennox Home app is lightyears ahead of the dated Lennox iComfort WiFi app. So much so, I’d consider recommending folks upgrade their thermostats even if their 10f81 is still functioning.Install was a breeze since the wiring is the same between the wall plate connectors. Just note what color wire goes to each of the R, I+, I-, and C terminals. They’re in the same order on the S40 wall plate, but I did note my 10f81 used Philips set screws while the S40 set screws were flat head. The 10f81 set screws required the wiring to connect to the bottom of the terminals, but the S40 terminals had the wire ends coming into the top of the terminals. The wall plate for the S40, while slightly smaller than the 10f81 plate, has wider spaced mounting holes, requiring new holes in the wall, but the old ones will be covered by the plate. I made sure to turn power off to the furnace as suggested in installation documentation prior to rewiring to the new wall plate. I also used blue painters tape to keep the new S40 wallplate in place while I decided where the new mounting screws needed to go, starting with drilling one screw into the wall, then using a level to determine where the next screw needed to be placed in order to keep the plate level. I used a short level, balanced on the top two mounting prongs the thermostat will eventually click onto. Was pleased to feel how much less effort is needed to snap the S40 thermostat on and off compared to the old 10f81. Turned the furnace back on and waited for the thermostat to power up and initialize itself.The longest part of this install was the software set up of the S40. It’s easier if you install the Lennox Home app on your phone FIRST, create a Lennox account if you don’t already have one, and get logged into the app before proceeding. I added my HVAC company’s phone number when prompted, but that was about it, skipping the rest of the dealer setup portion. Supposedly you lose the 10 year warranty without dealer installation, but reading about the crazy expensive installation costs, I figured it’d be cheaper to just buy another thermostat if needed. My guess is that you’re actually buying that 10 year warranty through the dealer’s install fee, but that’s just a theory.
Retired Navy Veteran –
A solid DIY upgrade from the Lennox 10F81—especially if you catch it on sale
A quick note on installation: While this can be a DIY project, if your Lennox system is still under warranty, you should probably let a licensed tech handle it to avoid any issues with coverage.I didn’t upgrade by choice—my Lennox 10F81 display suddenly went blank one day. It still had power, but the screen was completely unresponsive, so I had no way to control the HVAC. Since that model isn’t even available on Amazon anymore, I went with the Lennox S40. After installing and dialing it in, it honestly feels like I have a whole new system.Installation was easier than I expected. The mounting is very similar to the old unit, and I used the same 4 wires (confirmed 24VAC on the R wire using the C wire as the common—see my wiring photo). I didn’t have to patch or repaint anything since two of the original screw holes lined up perfectly. The screen is clear and responsive, though it can be a little slow when entering things manually. The weather screensaver is a nice touch when it’s idle.The app walks you through setup step-by-step—just take a picture of your old wiring first so you don’t have to guess. I also added it to Alexa, which was simple. I used ChatGPT a bit to help fine-tune the “feels like” temperature and humidity settings. I’m retired and home most of the day, so I built a schedule that actually fits how I live. I didn’t want to rely on geofencing “guessing” when I’m home or not; for me, the cost to reheat the home after being away a few hours is minimal anyway.Right after installing, it flagged an airflow issue. Turned out to be a dirty humidifier pad—something I never would’ve caught with the old thermostat. The diagnostics alone make this worth it. I’ve since set 6-month reminders for my filter and pad so I don’t forget down the road. I also have Allergen Defender turned on using my zip code. It monitors local air quality and runs the system more when pollen is high, which is a nice bonus.Comfort-wise, humidity control is the biggest difference. With dew point and the humidifier working together, the house feels warmer without turning the heat up (running at 71° “Feels Like” at 36% humidity feels perfect). Once I got everything set (72–75, cooler at night), I stopped touching it. No big swings, no constant adjusting.Price-wise, I paid $387.98 total. The unit was on sale for $329.98 (about 62% off), plus $45 overnight shipping and no tax. At that price, it made sense.If you’re coming from a Lennox 10F81—or dealing with a blank screen—this is the upgrade path. Compared to the 10F81, the S40 actually feels like it’s managing the system instead of just reacting to it.
Sue Ellen Hendrixson –
Lennox Wi-Fi Thermostat was an excellent choice.
Excellent thermostat. Works well with the phone app. an monitor and set temperature remotely. Programming is very easy. Expensive but works very well.