Do smart thermostats save money?

Updated June 2026Independently researchedNo paid placement.

What do the studies actually say about thermostat savings?

Ecobee’s own research claims users save up to 23 percent on heating and cooling, but independent studies paint a more conservative picture. The American Council for an Energy-Efficient Economy (ACEEE) reviewed multiple smart thermostat studies and found average savings between 8 and 12 percent for heating and around 15 percent for cooling. Lawrence Berkeley National Lab’s analysis estimated similar numbers, with the caveat that real-world savings depend on how aggressively you set the hold temperature and how often you override the schedule. The important nuance: these averages come from households that previously did little to no programming or manual adjustment. If you already kept your home at 68°F in winter and 78°F in summer, a smart thermostat adds almost nothing to your bottom line. The device’s main trick is making it easy to set a schedule and stick to it, which many people didn’t do before.

Which factors have the biggest impact on your savings?

Three variables matter most: your climate, your home’s insulation, and your previous thermostat habits. In extreme climates (very hot summers or very cold winters), a smart thermostat’s setback periods create meaningful reductions because the HVAC system runs for long stretches. In temperate climates like the Pacific Northwest or California coast, the savings drop to the low single digits or even zero. Home insulation quality matters because a tight building envelope holds temperature longer, giving you more flexibility to set back the thermostat without discomfort. A drafty home will recover from setbacks quickly, erasing much of the benefit. Finally, the biggest variable is you. If you used to leave the thermostat at 72°F year-round, a smart device will probably save a lot. If you already manually adjusted it when you left the house, the gain is minimal.

When do smart thermostats fail to pay for themselves?

In mild climates where HVAC runs only a few weeks per year, the annual savings may be less than the device’s cost. For example, a household in San Diego with no air conditioning and a gas furnace used only a few dozen days a winter might save under ten dollars a year. At that pace, a thermostat that costs a few hundred dollars would take decades to pay back. Similarly, if you live in a very small apartment with low energy bills, the percentage saved is small in absolute terms. Another scenario: people who already used a programmable thermostat correctly and kept consistent set points. Smart features like occupancy sensing and learning do help, but the incremental savings over a well-programmed schedule are often too small to justify the premium. In these cases, you’re paying for convenience, remote control, or integration with other smart home gear, not energy savings.

Geofencing vs. learning vs. manual scheduling: which saves most?

Geofencing, which uses your phone’s location to automatically switch to an away or home mode, tends to produce the largest savings because it ensures you never heat or cool an empty home. But it depends on consistent phone carriage and a reasonable distance radius. If you often leave your phone behind or the geofence radius is too large, you might trigger the system back on early. Learning algorithms, like those in the Nest, try to infer your schedule and preferences over time. They’re convenient, but studies show they rarely outperform a simple, well-set manual schedule. Manual scheduling remains the most reliable approach for savings, especially if you set a tight schedule and stick to it. A smart thermostat with remote app control lets you adjust on the fly, which can beat any algorithm. For most people, the best savings come from combining geofencing with a solid manual schedule, letting the phone handle absences while a fixed schedule covers predictable daily routines.

How to find utility rebates and calculate your payback period

Utility rebates are one of the biggest reasons a smart thermostat can pay for itself quickly. Many electric and gas companies offer rebates ranging from a modest discount up to essentially covering the full cost. Check your utility’s website or the Energy Star rebate finder tool for current offers. Some states also have income-qualified programs that can provide a free thermostat and installation. To estimate your payback, take your annual heating and cooling costs (look at your utility bills for the previous year) and multiply by the expected savings percentage. For a typical home spending about a thousand dollars a year on HVAC, a 10 percent saving means about a hundred dollars annually. If the thermostat costs two hundred dollars after rebate, payback is two years. If your bill is lower or your climate milder, payback stretches much longer. Keep in mind that many thermostats have a lifespan of eight to ten years, so even a three-year payback still leaves years of net savings.

The honest verdict: who should buy a smart thermostat and who shouldn’t?

You should buy one if you live in a climate with distinct heating and cooling seasons, you currently set the temperature manually throughout the day (or leave it constant), and you want remote control for comfort and convenience. Also consider it if you have a vacation home, or if you want to integrate your thermostat with other smart devices like lights or voice assistants. In these cases, the savings plus convenience easily justify the investment. You should probably skip it if you live in a mild, consistent climate, if you already religiously adjust your thermostat before leaving home, or if your energy bills are very low to begin with. Also avoid it if your home lacks a C-wire and you’re not comfortable doing simple wiring. The upfront cost and installation hassle won’t be recouped in any reasonable time. For everyone in between, the decision comes down to whether the peace of mind and smartphone control are worth a modest net outlay.

Frequently asked questions