Thermostats: Lennox S40, Nest, ecobee and More
Pure Comfort installs and sets up Lennox S40, Nest, ecobee and Honeywell thermostats, matched to your heating and cooling equipment and wiring so staging, humidity and zoning controls work the way they should.
As a Lennox Premier Dealer, we set up and register Lennox comfort systems and their controls.
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What the Thermostat Controls
A thermostat senses temperature and tells the HVAC system when to heat, cool or circulate air. Depending on the equipment, it may also manage operating stages, fan settings, humidity accessories or connected-system features.
A control cannot correct every comfort problem. Wiring faults, equipment safeties, airflow issues and poor thermostat placement can create symptoms that look like thermostat failure.
Common Thermostat Types
- Programmable ThermostatsProgrammable controls use scheduled temperature changes to support consistent routines without requiring remote connectivity.
- Wi-Fi and Smart ThermostatsConnected controls may add app access, scheduling and usage features. Compatibility and power requirements should be confirmed before installation.
- Communicating ControlsCommunicating thermostats exchange more detailed operating information with compatible equipment and may manage features unavailable through conventional wiring.
Thermostats We Install: Good, Better, Best
The thermostat is the brain of your system. We install everything from simple programmable thermostats to Google Nest, ecobee and the Lennox S40, which unlocks every feature of a Lennox communicating system. Here's how they compare.
Braeburn, Emerson & Honeywell
Trusted, easy-to-use thermostats from the big names. Great for straightforward systems and budget-minded upgrades.
- Programmable and Wi-Fi models
- Works with most standard systems
- Simple, familiar controls
Smart Thermostats
Wi-Fi smart thermostats you control from your phone. Lennox E30 and E40, Google Nest and ecobee all work with most equipment.
- Remote control and scheduling from your phone
- Energy reports and learning features
- Lennox E40 works with multi-stage equipment
Lennox S40
Lennox's top smart thermostat. It talks directly to Lennox communicating equipment to fine-tune comfort, efficiency and air quality.
- Unlocks every feature of Lennox communicating systems
- Alerts and remote diagnostics
- 10-year limited warranty
Compare our thermostat options
| Thermostat | Type | Works best with | Highlights | Details |
|---|---|---|---|---|
| Good · Standard brands | ||||
| Braeburn | Programmable or Wi-Fi | Most standard systems | Reliable, budget-friendly | Learn more ↗ |
| Emerson | Programmable or Wi-Fi | Most standard systems | Simple, trusted controls | — |
| Honeywell Home | Programmable or Wi-Fi | Most standard systems | Familiar, easy to use | Learn more ↗ |
| Better · Smart thermostats | ||||
| Lennox E40 | Smart Wi-Fi | Multi-stage, non-communicating equipment | ENERGY STAR certified, universally compatible | Learn more ↗ |
| Lennox iComfort E30 | Smart Wi-Fi | Most systems | Versatile smart control | Learn more ↗ |
| Google Nest | Smart Wi-Fi | Most standard systems | Learns your schedule, phone control | Learn more ↗ |
| ecobee | Smart Wi-Fi | Most standard systems | Room sensors even out hot and cold spots | Learn more ↗ |
| Best · Lennox S40 | ||||
| Lennox S40 | Smart, communicating | Lennox communicating systems | Full system control, alerts, 10-year limited warranty | Learn more ↗ |
We'll recommend the right thermostat for your equipment. Installed thermostats start around $225, up to about $1,095 for a Lennox S40.
When a New Thermostat May Make Sense
Replacement may be appropriate when the existing control is damaged, inaccurate, unsupported or unable to operate the HVAC system’s available stages and features. Homeowners may also consider an upgrade for scheduling or remote access.
If the system does not respond correctly, diagnosis should come first. The actual issue may be in the furnace, air conditioner, heat pump or wiring.
Features to Compare
Compatibility First, Features Second
Choosing Compatibility Before Features
A thermostat offers little value if the HVAC equipment cannot use its functions. The decision should start with the system type, operating stages, wiring and connected accessories.
Pure Comfort can separate thermostat operation from equipment performance, then explain which control levels are compatible without adding features the homeowner does not need.
Installation and System Setup
Installation includes confirming wiring, power, equipment configuration and thermostat location. Controls for heat pumps, dual-fuel systems, zoning or communicating equipment require the correct setup to operate available stages safely and effectively.
After installation, Pure Comfort tests system response and walks the homeowner through the settings that matter for normal use.
Why Choose Pure Comfort for Thermostat Guidance
Checks the thermostat and HVAC equipment before recommending replacement
Matches controls to wiring, staging and accessory requirements
Experience with conventional and communicating HVAC systems
Explains settings plainly and services all major makes and models
Related Services and Guides
Frequently Asked Questions
Will any thermostat work with my HVAC system?
No. Equipment type, staging, wiring, power and communication requirements determine whether a thermostat is compatible.
What is a communicating thermostat?
It exchanges operating information with compatible HVAC equipment and can control functions that may not be available through conventional wiring.
Do smart thermostats require a C-wire?
Many connected thermostats need continuous power, but requirements vary by control and system. The available wiring should be checked before selection.
Can a thermostat cause short cycling?
It can contribute, but airflow restrictions, equipment controls and mechanical problems can create the same symptom. The complete system should be evaluated.
How much does thermostat installation cost?
A basic non-programmable thermostat starts at $225, including the part and installation. Wi-Fi models cost more, and a communicating thermostat like the Lennox S40 can be up to $1,095 installed. Thermostats cost less when we install them as part of a new system.
Which thermostat brands do you install?
We install all major brands, including ecobee, Google Nest, Honeywell, White-Rodgers, Trane, Emerson, Braeburn, ProStat and Lennox. We’ll make sure the thermostat you choose is compatible with your equipment and wiring.
Rebates you may qualify for
2026 utility programs for Northern Illinois homes. Amounts checked October 2026.
| Program | Equipment | Rebate |
|---|---|---|
| Nicor Gas | Smart thermostat | $25 |
| Nicor Gas | Furnace + smart thermostat bundle (95% / 97%+ AFUE) | $200 / $275 |
| ComEd | ENERGY STAR smart thermostat with a heat pump | +$75 |
The federal 25C tax credit ended for systems installed after December 31, 2025. Illinois income-qualified HEAR heat pump rebates (up to $8,000) are not available yet as of October 2026, and projects finished before the program opens will not qualify. We confirm the current status on your written quote. ComEd discounts come off your invoice when a ComEd heat pump-trained contractor installs qualifying equipment. Nicor Gas rebates require qualifying equipment and Nicor’s rebate application. Programs can change, so we confirm what your home qualifies for on your written quote. Programs and amounts can change, so confirm current details on the utility sites before you buy. Official details: Nicor Gas rebates · ComEd heat pump discounts.
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- Lennox Premier Dealer
- NATE-certified technicians
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- Licensed business in the Village of Streamwood
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