5 Best Whole-House Generators of 2026, Lab-Tested and Reviewed
Home standby generators from companies like Champion, Generac, and Kohler are pricey, but they provide immediate backup power during outages
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If you often lose power where you live, whether because of seasonal storms such as hurricanes or problems with the electrical grid, having a whole-house generator can be very convenient. It ensures that your appliances are available when you need them—even hardwired devices like your well pump, water heater, and air conditioning and heating systems—not to mention lifesaving devices like medical equipment.
These professionally installed units, also called home backup generators or whole-home generators, pump out lots of electricity. One characteristic that sets them apart from portable generators is the ability to kick on automatically when the power goes out, letting you go about your daily life almost as if there were no outage at all. They’re about the size of a central air conditioning unit and sit permanently on a concrete pad. They can run on natural gas, which provides an essentially limitless source of fuel, or on a large propane tank, which needs to be refueled much less often than the gas tank on a portable generator.
- Whole-House Generators: Best Large Models Best Small Models
- How CR Tests Generators
- Pros and Cons
Best Whole-House Generators With More Than 15,000 Watts
Large whole-house generators have an output of 15,000 watts or more, which means there’s enough power for all your appliances. On average, these big models run from 120 to 250 hours on a propane tank, which is a shorter range of duration than some of their smaller counterparts.
Best Whole-House Generators With Under 15,000 Watts
Smaller whole-house generators in our ratings are those that put out less than 15,000 watts of power. The upshot is that they often run longer on propane than larger standby generators. Note that while smaller models are less expensive to purchase, the installation costs are comparable with those of larger models, so your overall savings might not be as large as you expect.
How to Use Your Generator Safely
As we mentioned, there’s a risk of carbon monoxide (CO) poisoning with home standby generators, just as with portable generators. In fact, there’s new information on this risk from the Consumer Product Safety Commission.
In 2025, the CPSC reported findings from a case study of CO poisoning incidents involving stationary generators in Louisiana following Hurricane Ida, which caused widespread power outages in 2021. The CPSC received information on 256 homes that reported CO exposure and determined that 105 had CO exposure caused by stationary generators. (There were no deaths reported from those incidents, though residents from a dozen homes had symptoms of CO poisoning.)
“The 2025 CPSC report dispels the common misconception that stationary generators do not pose a risk of carbon monoxide (CO) exposure,” says Gabe Knight, a senior policy analyst for safety at Consumer Reports. “The report also makes clear that the current applicable voluntary standards are entirely inadequate to mitigate CO exposure risks, leaving consumers vulnerable.”
Carbon monoxide is an invisible, odorless gas. If people are exposed to high concentrations of CO, it can cause brain or heart damage, Knight says, or even death. But he says that prolonged exposure, even to lower levels of CO (which might not set off a typical CO alarm), can have negative health consequences, particularly for children, pregnant people, and those with preexisting health conditions. Early symptoms of CO poisoning include headache, dizziness, and nausea—problems that resemble a number of other conditions. So people might not recognize right away that they’re experiencing these symptoms due to CO exposure.
Here are CR’s recommendations for reducing the risk of CO exposure if you have a home standby generator:
- Make sure to have CO detectors installed throughout your home, and test them regularly. Specifically, Knight recommends CR detectors that are UL 2034 certified, or ETL listed, and be mindful of detectors without independent certification that are sold through third-party vendors like Walmart and Amazon. You can find good choices in our ratings of CO detectors, which are free to anyone.
- CR also recommends having low-level CO detectors, which are particularly important for older people, children, those with preexisting conditions, and pregnant women.
- Before installing a standby generator, be sure to harden your home’s exterior by sealing off openings where exhaust could enter, such as windows and dryer or crawl space vents.
- Install the generator as far from the home as possible. The CPSC recommends installing at a distance of 25 feet. You’ll also want to make sure that the generator is 25 feet away from any neighbors.
- Your installer should place the generator away from vulnerable spots, like basement windows, dryer vents, and any vents on the underside of the roof (known as soffit vents).
- Homeowners can also place a fan next to the generator exhaust to help push CO away from the home.
Pros and Cons of Standby Generators
There are many benefits to installing a whole-house generator.
- Because they start automatically, unlike a sometimes stubborn gas-powered generator, there’s no futzing in the dark with flashlights to get them started.
- They give you a choice of fuel: propane, which can be stored in a large tank and is less risky than pouring a large supply of gasoline into a portable generator’s fuel tank, or natural gas, which provides an unlimited supply of power.
- Many run a self-diagnosis and let you know when maintenance is needed.
But there are downsides.
- Whole-house generators cost more than portables. Models in our ratings can range from $3,400 to nearly $7,000. By comparison, large portable generators in our ratings that can power a whole house start as low as $800.
- They’re large and require a level concrete pad outside your home, a bit like a central air conditioning unit.
- They require professional installation, sometimes involving a plumbing/heating contractor for a gas line, a general contractor for the concrete pad, and an electrician to hook up the generator to your electrical panel.
- The installation can be more expensive than the unit itself, ranging from about $5,000 to $10,000 or more, and smaller units cost almost as much to install as larger ones.
How CR Tests Generators
To test how a generator will perform when you need it most, our expert engineers take every model to our test facility and load it up with a variety of essentials you might want to power during an outage, such as a space heater, refrigerator, or window air conditioner.
Our testers make sure the generator can handle the load it’s designed for and also determine what happens when a sudden spike in voltage hits, such as when your fridge’s compressor kicks on when the generator is already close to capacity. The best models take that in stride, while lower-performing generators bog down or even stall. We also look at how efficiently a generator uses fuel and how long it runs on a tank of propane. Check out our generator buying guide for more details on our intensive testing program.
