Do Smart Thermostats Actually Save Money?
Smart thermostats can save about 8% on heating and cooling. Here's where the savings come from, how rebates help and the settings that matter most.
Yes, for most homes. ENERGY STAR says certified smart thermostats save the average home about 8% on heating and cooling, or roughly $50 a year, and more in homes with high bills. Savings come from automatic setbacks when you sleep or leave. Utility rebates and demand response bonuses can cut the payback to a year or two.
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Heating and cooling are the biggest energy costs in most American homes. ENERGY STAR says they make up almost half of the average household’s annual energy bill, more than $900 a year. So when a gadget promises to trim that number automatically, it’s worth asking whether the savings are real.
The short answer: smart thermostats do save money for most households, but not because they’re magic. They save money by doing consistently what most of us forget to do, which is turning the heat or air conditioning down when nobody needs it.
This guide explains where the savings come from, how much you can realistically expect, how utility rebates change the math and which settings make the biggest difference.
How much smart thermostats really save
ENERGY STAR certifies smart thermostats based on actual field data from homes, not lab claims. According to ENERGY STAR, certified smart thermostats save the average home about 8% on heating and cooling costs, or about $50 per year. Homes with high heating and cooling bills can save more, up to about $100 per year by ENERGY STAR’s estimate.
The U.S. Department of Energy offers a related rule of thumb: you can save as much as 10% a year on heating and cooling by turning your thermostat back 7 to 10°F for 8 hours a day from its normal setting.
Your results depend on a few factors:
- Your habits today. If you already adjust your thermostat diligently, a smart model adds less. If your house sits at 72°F all day while it’s empty, it adds a lot.
- Your climate. Long, cold winters or hot summers mean bigger bills and more room to save.
- Your HVAC system. Furnaces and central air respond well to setbacks. Heat pumps need special handling (more on that below).
- How the house is used. A home that’s empty during workdays saves more than one where someone is home all day.
Key takeaway: A smart thermostat saves money by automating setbacks. If your home is often empty or you rarely adjust the temperature now, expect real savings. If you already manage it carefully, the gain is smaller.
Where the savings actually come from
Automatic schedules and setbacks
The biggest win is simple: lowering the heat at night and when you’re out, then bringing it back before you wake up or return. Smart thermostats make this automatic, and many learn your patterns over time.
Occupancy and geofencing
Many models use motion sensors or your phone’s location to detect when everyone has left and switch to an “away” setting. When you head home, they start heating or cooling so the house is comfortable when you arrive. This catches the irregular days that a fixed schedule misses.
Remote control
Forgot to adjust the thermostat before a weekend trip? You can fix it from your phone. It’s a small feature that prevents expensive mistakes.
Usage reports and alerts
Monthly reports show how many hours your system ran and why. Some models alert you to unusual runtimes, which can flag a dirty filter or failing equipment early.
Utility programs
Many smart thermostats can enroll in utility demand response programs, which pay you to let the utility adjust your temperature slightly during a few peak hours each year. This is the simplest form of a virtual power plant.
Smart vs programmable vs manual thermostats
| Feature | Manual | Programmable | Smart (Wi-Fi) |
|---|---|---|---|
| Automatic schedule | No | Yes, if you set it | Yes, often learns or suggests one |
| Adjusts when you leave | No | No | Often, via geofencing or sensors |
| Remote control by app | No | No | Yes |
| Energy reports | No | Rarely | Yes |
| Utility rebates and programs | Rarely | Sometimes | Often, especially ENERGY STAR models |
| Typical savings potential | Depends entirely on you | Good if programmed correctly | Good, with less effort |
Programmable thermostats can save just as much in theory. The catch is that many people never program them, or override the schedule and forget to resume it. Smart thermostats reduce that human error.
How utility rebates change the math
Rebates are what turn a smart thermostat from “nice to have” into a quick payback. Many utilities offer instant discounts, mail-in rebates or bill credits for ENERGY STAR certified smart thermostats. Some also pay an enrollment bonus or seasonal credits if you join a demand response program.
Amounts vary a lot by utility and change often, so check before you buy:
- Use the ENERGY STAR Rebate Finder. Enter your ZIP code on the ENERGY STAR smart thermostat page to see current offers.
- Check your utility’s website for “thermostat rebate,” “smart thermostat” or “demand response.”
- Look at your utility’s online marketplace. Some utilities sell thermostats with the rebate already applied.
- Read the eligibility rules. Many rebates require an ENERGY STAR certified model, a specific HVAC type or professional installation.
Here’s a simple way to estimate payback:
Payback (years) = (thermostat price + installation - rebates) / estimated annual savings
If rebates cover a large share of the price, payback can arrive within a year or two. Without rebates, and in a mild climate, it can take several years.
The settings that make the difference
A smart thermostat only saves money if it’s set up well. These are the settings that matter most.
1. Set real setback temperatures
Choose a sleep and away temperature that’s meaningfully different from your comfort setting. The DOE guideline is 7 to 10°F back for about 8 hours. Start smaller if needed, then push it further as you get used to it.
2. Turn on away mode or geofencing
Make sure every adult’s phone is connected if you use location-based away mode. Otherwise, the thermostat may think someone’s still home.
3. Avoid constant manual overrides
Each time you bump the temperature, many thermostats hold it until the next scheduled change. Frequent overrides can quietly erase your savings.
4. Use eco or energy-saving features
Most brands offer “eco” temperatures or savings suggestions. Accept the ones you can live with.
5. Handle heat pumps carefully
The DOE notes that deep setbacks can backfire with heat pumps in heating mode, because recovering from a big setback may trigger expensive backup electric resistance heat. If you have a heat pump, use a thermostat designed for heat pumps and keep setbacks modest. Our heat pump vs furnace guide explains how these systems differ.
6. Place it well
A thermostat near a sunny window, kitchen or drafty door reads the wrong temperature. Remote room sensors, offered with some models, help in homes with uneven temperatures.
When a smart thermostat won’t save much
Be realistic. A smart thermostat may not pay off if:
- Someone is home all day and needs a steady temperature.
- You already use a programmable thermostat well.
- Your climate is mild and your heating and cooling bills are small.
- Your home loses heat fast through air leaks and poor insulation. Fix those first; our guide to a DIY home energy audit shows how to find them.
- Your HVAC system isn’t compatible. Some older systems or homes without a common wire (C-wire) need an adapter or professional installation.
Where to start
- Check compatibility. Most brands have an online tool where you enter the wire labels on your current thermostat.
- Search for rebates with the ENERGY STAR Rebate Finder and your utility’s site before buying.
- Pick an ENERGY STAR certified model so you qualify for more rebates and programs. Popular brands include Google Nest, ecobee and Honeywell Home.
- Install it yourself if you’re comfortable turning off power and moving labeled wires, or hire an HVAC technician.
- Set your schedule and setbacks on day one, and turn on away mode.
- Enroll in a utility program if one is available and the terms work for you.
- Review your energy reports after a month and fine-tune.
If you’re building out a connected home, our guides on how to set up a smart home and Alexa vs Google Home vs Apple HomeKit can help you choose an ecosystem that works with your thermostat.
The bottom line
Smart thermostats do save money for most households, typically through automatic setbacks that cut heating and cooling use. ENERGY STAR puts the average at about 8%, or roughly $50 a year, with more for homes with high bills. Combine an ENERGY STAR model with a utility rebate, set real setbacks and avoid constant overrides, and the device often pays for itself quickly. If your bills keep climbing anyway, our explainer on why electricity bills are rising covers the other forces at work.
Sources
- ENERGY STAR: Smart thermostats — field-data certification, features, heating and cooling share of bills, Rebate Finder
- ENERGY STAR: Smart thermostats technical bulletin — average savings of 8% on heating and cooling, about $50 per year
- U.S. Department of Energy: Home upgrades — up to 10% a year by setting back 7 to 10°F for 8 hours a day
- U.S. Department of Energy: Energy Saver guide — heat pump owners should use thermostats designed for heat pumps
Frequently asked questions
How much money does a smart thermostat save per year?
ENERGY STAR says certified smart thermostats save the average home about 8% on heating and cooling, or roughly $50 a year. Homes with high heating and cooling bills can save up to about $100 a year. Your savings depend on climate, HVAC type, how often the home is empty and how you manage the temperature today.
Is a smart thermostat worth it?
For most homes, yes, especially if the house is empty during the day or you rarely adjust the temperature now. Utility rebates and demand response bonuses can cut the net cost sharply, which shortens payback. It's less worthwhile if someone is home all day, your climate is mild or you already use a programmable thermostat well.
Do smart thermostats work with heat pumps?
Many do, but set them up carefully. The Department of Energy notes that big setbacks with a heat pump in heating mode can trigger backup electric resistance heat during recovery, which can erase savings. Choose a model designed for heat pumps, configure the system type correctly during setup and keep setbacks modest.
Are there rebates for smart thermostats?
Often, yes. Many utilities offer rebates, instant discounts or bill credits for ENERGY STAR certified smart thermostats, and some add bonuses for joining demand response programs. Amounts vary by utility and change often. Use the ENERGY STAR Rebate Finder with your ZIP code and check your utility's website before you buy.
What temperature should I set my thermostat to save money?
Set it back 7 to 10°F from your normal temperature for about 8 hours a day, such as overnight or while you're at work. The Department of Energy says that can save up to 10% a year on heating and cooling. Choose comfortable settings you'll stick with, since frequent manual overrides cancel much of the savings.
Do I need a C-wire for a smart thermostat?
Many smart thermostats need a common wire (C-wire) for steady power, but not all. Some models work without one, and others include a power adapter for homes that lack it. Check the manufacturer's online compatibility tool by entering the wire labels from your current thermostat before you buy.
Do smart thermostats raise privacy concerns?
They collect data on temperature, schedules and sometimes occupancy, and that data goes to the manufacturer's cloud and possibly your utility if you enroll in a program. Review the privacy settings in the app, decide whether to share location for geofencing and read program terms before enrolling in utility events.
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Manishdai
Manishdai writes about the technology that is reshaping every industry — from AI agents and cloud platforms to healthtech, fintech and the IT companies building it all across the United States.
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