Best Smart Thermostats in 2025: Real Savings, Simple Control, and Heat-Pump Smarts
Updated October 2025
Tested by Alex Rivera
Heating and cooling still consume about half of the energy in most homes, so a smart thermostat remains one of the highest-ROI upgrades you can make. This 2025 guide compares the best models (ecobee, Nest, Honeywell, and Emerson), covers C-wire and heat-pump compatibility, and shows a safe DIY install—plus utility rebates to lower the cost.
Expanding your smart home? Pair your thermostat with smart bulbs for presence-based scenes that optimize both comfort and efficiency.
Our top pick: ecobee Smart Thermostat Premium
The most complete smart thermostat for 2025 — energy-saving intelligence, occupancy sensing, air-quality awareness, and broad smart-home compatibility.
Why a smart thermostat matters in 2025
Heating and cooling still dominate home energy bills. According to the U.S. Energy Information Administration, HVAC accounts for nearly half of residential consumption. Smart thermostats combine sensors, schedules, and weather awareness to reduce waste while keeping your home comfortable.
Look for the ENERGY STAR® label. These models are tested on real-world savings and often qualify for rebates—start with the ENERGY STAR Rebate Finder. If you’re on a heat pump, features like auxiliary heat lockout can materially cut winter costs—our Aux Heat Lockout guide explains ideal settings.
Before you buy: 6 must-knows
- HVAC compatibility: Identify single-stage, two-stage, or variable-speed. Most modern models work with gas, electric, boiler, and heat-pump systems; cold-climate heat pumps need careful setup—see our heat-pump buyer’s guide.
- C-wire (common wire): Required for continuous 24V power. If missing, use an adapter or add one at the air handler. See C-wire explained and our DIY setup guide.
- Wi-Fi reliability: Ensure stable 2.4 GHz coverage; weak signal causes dropouts.
- Design & interface: You’ll use it daily—pick a responsive interface and an app you like.
- Room sensors & presence detection: Sensors average comfort across rooms. Compare options in our sensor comparison.
- Rebates & demand response: Utilities often offer rebates and bill credits—start with our state directory.
Smart thermostat comparison (2025)
| Model | Price* | Smart Ecosystem | Heat Pump Support | Room Sensors | Key Extras |
|---|---|---|---|---|---|
| ecobee Smart Thermostat Premium | ≈ $249–$299 | Alexa, Google, Apple Home, SmartThings | ✔ Yes (Aux heat lockout) | ✔ Yes | Air-quality sensor, radar presence, ENERGY STAR |
| Nest Learning Thermostat (3rd-gen) | ≈ $199–$249 | Google Home, Alexa (limited) | ✔ Yes | Optional Nest sensors | Auto-Schedule, geofencing, Farsight display |
| Honeywell Home T10 Pro | ≈ $179–$229 | Alexa, Google | ✔ Yes | ✔ Yes | Humidity control, multi-room averaging |
| Emerson Sensi Touch | ≈ $129–$169 | Alexa, Google, Apple Home (some models) | ✔ Yes | ✖ No | Touchscreen, easy app setup |
*Prices vary by retailer and rebate eligibility.
The 4 best smart thermostats (reviews)
ecobee Smart Thermostat Premium
Supports nearly all HVAC types—including variable-speed and dual-fuel heat pumps. Radar presence was the most consistent in our tests, and built-in IAQ/humidity data helped refine schedules. For heat pumps, combine with correct aux heat lockout to avoid expensive backup heat.
Pros
- Excellent heat-pump controls (aux lockout, staging)
- Built-in IAQ and humidity sensors
- Works with Alexa/Google/Apple/SmartThings
- SmartSensor option for room averaging
Cons
- Premium price
- Setup wizard is thorough but long
Next reads: Thermostat placement · Room sensor tips
Google Nest Learning Thermostat (3rd-gen)
The metal dial remains delightful. Auto-Schedule learns quickly, geofencing is simple, and Farsight makes status visible across the room. For heat-pump optimization, compare settings with ecobee in our heat-pump showdown and see real-world Away/Vacation behavior in our modes test.
Pros
- Beautiful, durable design
- Auto-Schedule + geofencing
- Farsight glanceable display
Cons
- No built-in IAQ sensor
- Limited Apple Home support
Shines for multi-room balance. Remote sensors track temperature and occupancy, averaging the rooms you pick. One of the few consumer models with integrated humidity control—great if you run a whole-home humidifier/dehumidifier. See placement best practices in our sensor comparison.
Pros
- Supports humidifiers/dehumidifiers
- Accurate occupancy-aware averaging
- Flexible scheduling in app
Cons
- Occasional app bugs
- Design less premium than ecobee/Nest
Solid reliability, geofencing, and clear touchscreen controls at a lower price. Lacks room sensors/IAQ, but nails the basics. If wiring your first smart thermostat, check our C-wire guide for adapter options.
Pros
- Affordable and dependable
- Simple installation + app pairing
- Works with Alexa/Google (some Apple Home models)
Cons
- No IAQ or occupancy sensors
- Basic industrial design
DIY installation (C-wire & safety)
Most people can install a modern smart thermostat in under 30 minutes. Follow these steps carefully or use our visual walkthrough: How to set up a smart thermostat.
- Turn off HVAC power at the circuit breaker.
- Remove the old faceplate and take a photo of wire labels.
- Detach wires, mount the new backplate, and pull wires through.
- Connect wires to matching terminals. Use a C-wire adapter if needed (C-wire explained).
- Attach the new faceplate, restore power, and connect to Wi-Fi.
- Run system test, enable Home/Away, and link sensors (see sensor tips).
Need help with placement to avoid hot/cold bias? See our thermostat placement guide.
FAQ
How much can a smart thermostat really save?
ENERGY STAR-certified models commonly save ~8–12% annually, depending on climate, schedule accuracy, and occupancy sensing. Real wins come from correct scheduling, aux heat lockout on heat pumps, and good placement.
Do I need geofencing if I have room sensors?
No. Geofencing (phone location) is optional; room sensors detect presence at home. Power users combine both. See geofencing vs occupancy sensing.
Which thermostat is best for cold-climate heat pumps?
Pick a model with fine-grained aux-heat control (ecobee Premium is strong). Then set an appropriate lockout temperature to prevent expensive emergency/aux heat. Start with our heat-pump thermostat guide.
Are rebates worth the paperwork?
Yes—rebates can materially lower upfront cost and demand-response programs may pay annual bill credits. Begin with our rebate directory and the ENERGY STAR Rebate Finder.
How we tested
We prioritize heat-pump behavior, aux-heat controls, sensor accuracy, and app reliability. We evaluate installation clarity, placement sensitivity, and daily usability. Our picks favor models with proven ENERGY STAR performance and broad ecosystem support.
Bottom line
For best overall savings and integration, choose the ecobee Smart Thermostat Premium. If you prefer simplicity and design, the Nest Learning Thermostat remains a joy to use. The Honeywell T10 Pro is ideal for multi-room comfort and humidity control, and the Emerson Sensi Touch delivers dependable value under $150.
Round out your setup with smart bulbs and smart locks with cameras. Tinkerers? Explore our 2025 best 3D printers for weekend projects.
