Lennox S40 Smart Thermostat Matter Compatibility

Lennox S40 Smart Thermostat Matter compatibility

The Lennox S40 Smart Thermostat (part 107088, catalog 22V24) is a Wi-Fi touchscreen communicating thermostat. It is certified for Matter 1.3 under CSA25B3DMAT47759-24, runs Matter over Wi-Fi, and needs no Thread border router. MatterCheck's thermostat type matrix lists Yes for pairing and control in Apple Home, Google Home, Amazon Alexa, SmartThings, Home Assistant, Homey and Hubitat. MatterAlpha's December 2025 coverage additionally names Apple Home, Google Home, Amazon Alexa and Samsung SmartThings as supported ecosystems for the L40 and S40 Matter update.

Matter transport and CSA certification facts

The CSA DCL record for this model lists the product name "Lennox S40 Smart Thermostat," part number 107088, and a device type of thermostat. MatterAlpha lists the latest certified firmware as 04.38.0087, Matter Specification Version 1.3, and network transport Matter over Wi-Fi. It also shows the current certification CSA25B3DMAT47759-24 certified on Tuesday, October 14, 2025, plus an earlier firmware 04.38.0081 certified September 24, 2025 under CSA2592BMAT47229-24.

MatterAlpha's news report says Lennox requires S40 firmware 4.38 or higher before owners can enable Matter; the on-device code is then scanned by the preferred ecosystem. Because this is Matter over Wi-Fi, no Thread border router is involved.

Lennox S40 Matter platform matrix

These are MatterCheck's type-level matrix answers for thermostats; they are not lab tests. Product-specific source differences follow the table. You can also check current platform support in MatterCheck's compatibility checker.

MatterAlpha's December 12, 2025 update report names Apple Home, Google Home, Amazon Alexa, and Samsung SmartThings as Matter ecosystems for the L40/S40. It does not name Home Assistant, Homey, or Hubitat; those rows remain MatterCheck type-level Yes answers rather than product-specific confirmations. Apple Home and Amazon Alexa automation-start cells are Unknown in MatterCheck's matrix no official source or dated hands-on report in the sources used confirms them.

Cross-platform comparison for Lennox S40

In the type matrix, every listed platform pairs and controls thermostat devices. Differences appear only in "Starts automations": Apple Home and Amazon Alexa are Unknown, while Google Home, SmartThings, Home Assistant, Homey, and Hubitat are Yes. Controlled-by-automations is Yes for all seven. Product-specific reporting is narrower: MatterAlpha names four major ecosystems as supported by the S40's Matter update, and none of the sourced product reviews provide hands-on Matter pairing results for the other three platform rows.

This means an S40 owner with a Google Home or SmartThings setup has an unqualified Yes automation-start answer in MatterCheck's matrix; an Apple Home or Alexa owner would need a dated, named confirmation to move that Unknown cell. No product-specific evidence in the sources contradicts the type matrix.

Lennox S40 Matter pairing steps

MatterAlpha reports these steps from Lennox's support FAQ for enabling Matter on the S40:

1. Meet Lennox's precondition of firmware 4.38 or higher with the S40 connected to the same Wi-Fi network, then follow the on-device steps below.
2. Tap Matter Settings on the main menu.
3. Tap Make Discoverable.
4. Tap Show Code.
5. Scan the QR code with the preferred smart home ecosystem.
6. Wait for "Pairing Successful" on the thermostat.

After pairing, the thermostat can be used in scenes, routines, and automation. For sharing across multiple ecosystems, Matter's multi-admin feature may apply, but the source does not document Lennox-specific multi-admin steps.

Lennox S40 specifications and limits

• LennoxPros lists catalog 22V24/model S40 as a communicating touchscreen smart thermostat, Wi-Fi enabled, universal 3 Heat/2 Cool, 7-day programmable, auto changeover, and intelligent recovery.
• Physical size from LennoxPros: height 4.438 in, width 7.063 in, depth 0.75 in; the display is a 7-inch high-definition color touchscreen measured diagonally.
• LennoxPros says the S40 recognizes model and serial number information for Lennox digitally communicating products and uses a 4-wire standard thermostat wiring setup. Lennox recommends 18-22 AWG shielded thermostat cable for I+ and I- communication terminals.
• For conventional, non-communicating HVAC systems, LennoxPros says the S40 requires the optional Equipment Interface Module 22X18 (EIM). The S40 with EIM works with most 24VAC furnaces, air conditioners, air handlers, and heat pumps up to 3 heat/2 cool, but not with other brands of communicating HVAC equipment.
• LennoxPros lists optional accessories: Smart Room Sensor 22V25, Wireless Extender 22V26, Smart Air Quality Monitor 21P02, EIM 22X18, Genesis 18/2 Plenum Rated Network Cable 22C97, PureAir S air purification, and optional iHarmony zoning for up to 4 zones.
• LennoxPros describes Schedule IQ, One-Touch Away Mode, Smart Away using geo-fencing, Weather-On-Demand, and up to four schedules.
• LennoxPros says a 10-year residential warranty applies, and the box includes an Installer Quick Start Guide and a Homeowner Quick Start Guide.

Reviewer and owner feedback for Lennox S40

• Electro Box's August 2026 review says setup feels simple and the interface is intuitive, but user ratings average about 3.4 out of 5 stars; some users report app crashes and reliability concerns, with clearing cache a temporary fix.
• Electro Box says some users noticed temperature readings become inaccurate when the screen is illuminated, though readings stabilize when the display dims.
• Electro Box says room-by-room temperature customization is a standout, and Smart Away Mode uses GPS to adjust temperatures when you leave.
• The Inside Review's June 2025 review of Amazon reviews reports most customers achieve flawless pairing with Lennox systems. Four labeled wires and two mounting screws often allow installation in under ten minutes; a guided app walkthrough is all that's needed.
• The Inside Review reports recurring complaints about high price compared with Ecobee or Nest and warranty confusion: online third-party buys may default to the marketplace seller's policy, with one reviewer citing a 20% restocking fee if returned.
• The Inside Review says no widespread reports of serious defects or hidden malfunctions surfaced in verified customer reviews.
• Lim Team's October 2025 hands-on calls the S40 a straightforward upgrade for previous Lennox communicating models, citing a user who noted a 'direct swap that used the same 4 wire set up,' but calls the unit proprietary with high initial cost.

Lennox S40 Smart Thermostat: buy if or skip if

• Buy if you own Lennox communicating HVAC equipment and want a Matter 1.3 Wi-Fi thermostat with a 7-inch HD display, 3 heat/2 cool control, optional zoning, and air-quality accessories.
• Buy if you want on-device Matter pairing after firmware 4.38 and use Apple Home, Google Home, Amazon Alexa, or Samsung SmartThings as named by MatterAlpha.
• Skip if you have a non-communicating HVAC system and do not want to add the EIM; LennoxPros says conventional systems require the separate Equipment Interface Module.
• Skip if you need product-specific Matter confirmations for Home Assistant, Homey, or Hubitat, or if you rely on Apple Home or Amazon Alexa starting automations from the S40; those specific cells are type-level only or Unknown in the sources used.
• Skip if upfront price is a concern: MatterAlpha lists an Amazon third-party price of $707 in December 2025, and The Inside Review notes third-party smart thermostats often retail for $200–$250, and that some customers find the S40's upfront cost steeper than popular alternatives like Ecobee and Nest.