Best Home Standby Generators

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The short answer

For most homes, a Generac Guardian air-cooled standby generator in the 14–24kW range is the safe default. Generac is the most widely installed brand, with the largest network of certified installers. A Generac Guardian 24kW can typically power an average-size home including central AC, while a 14kW unit covers essentials and some comfort loads for less money. Champion’s 14kW aXis is the value alternative, and Briggs & Stratton and Kohler are strong options if you have a good local dealer. Whatever you buy, professional installation, permitting and a correctly sized transfer switch matter as much as the brand.

Our picks at a glance

Pick	Model	Size class	Fuel	Best for	Amazon
Best overall	Generac Guardian 24kW	24kW air-cooled	Natural gas / LP	Whole home incl. central AC	Check price
Best mid-size	Generac Guardian 14kW	14kW air-cooled	Natural gas / LP	Essentials plus some AC	Check price
Best value	Champion 14kW aXis	14kW air-cooled	Natural gas / LP	Budget whole-home backup	Check price
Best dealer alternative	Briggs & Stratton PowerProtect	Multiple sizes	Natural gas / LP	Buyers with a B&S dealer nearby	Check price
Best small standby	Generac Guardian 10kW	10kW air-cooled	Natural gas / LP	Essential circuits only	Check price

Standby output is lower on natural gas than on propane (LP). Check the rating for your fuel type on the spec sheet. Prices vary widely, and installation often costs as much as the unit or more.

How we picked

We compared manufacturer specifications, owner reviews and published reviews, along with installer and service availability. For standby generators, the most important factors are output on your fuel type, transfer switch options (whole-house vs. essential circuits, load management), installer network, warranty length, remote monitoring, noise and exercise-cycle behavior.

1. Generac Guardian 24kW — Best overall

The Guardian series is the best-selling home standby line in the US, and the 24kW model is a common choice for whole-home backup. It can usually carry central AC, an electric water heater and most household loads. It’s typically paired with a 200-amp automatic transfer switch and Generac’s load-management modules, which shed big loads when needed. Most Guardian models include Generac’s Mobile Link Wi-Fi monitoring.

Who it’s for: homeowners who want the whole house to keep running, AC included, with minimal thought.

Good to know: availability of installers and parts is the biggest reason to choose Generac. Confirm your local installer is factory-authorized to keep the warranty.

Check the Generac Guardian 24kW on Amazon →

2. Generac Guardian 14kW — Best mid-size

For smaller homes, or larger homes where you’re willing to skip some loads, 14kW covers refrigeration, heating, well or sump pumps, lights and electronics, and often a smaller AC with load management. It’s cheaper to buy and to run.

Check the Generac Guardian 14kW on Amazon →

3. Champion 14kW aXis — Best value

Champion’s standby units are generally priced below comparable Generac models and are sold with an automatic transfer switch in common bundles. Champion has a strong reputation in portable generators and offers a competitive warranty on its standby line.

Good to know: the installer network is smaller than Generac’s. Line up an installer before you buy.

Check the Champion 14kW aXis on Amazon →

4. Briggs & Stratton PowerProtect — Best dealer alternative

Briggs & Stratton’s standby line covers several sizes and is a solid option if you have a trusted dealer nearby. Kohler, sold mainly through dealers, is another well-regarded alternative.

Check Briggs & Stratton standby generators on Amazon →

5. Generac Guardian 10kW — Best small standby

If you only need to keep the essentials running (fridge, furnace, sump pump, lights, internet), a 10kW standby with an essential-circuit transfer switch is the most affordable way to get automatic backup.

Check the Generac Guardian 10kW on Amazon →

Sizing a standby generator

Home and loads	Typical size
Essential circuits only, no central AC	About 10–14kW
Average home, one central AC with load management	About 14–22kW
Larger home, whole-house with central AC	About 22–26kW
Very large home, multiple AC units, electric heat	Liquid-cooled 30kW+ (dealer sale)

A licensed electrician or installer should do a load calculation. Undersizing causes overloads, and oversizing wastes money and fuel.

Buying and installation checklist

• Fuel supply. Natural gas needs an adequately sized meter and line. Propane needs a properly sized tank, often 250–500 gallons for extended outages.
• Transfer switch. Decide on whole-house (service-rated) vs. essential circuits, and whether you need load management for AC.
• Permits and placement. Most areas require permits and set minimum clearances from windows, doors, vents and property lines. Follow the manufacturer’s and local code distances.
• Installer. Use a factory-authorized installer to keep the warranty valid.
• Maintenance. Plan for annual service: oil, filters, plugs and battery.
• Exercise cycle and noise. Standby units run a short weekly or monthly self-test. Check the noise and schedule settings.
• CO safety. Standby generators sit outdoors, but you should still keep battery-backed CO alarms inside. Shop CO alarms

Air-cooled vs. liquid-cooled

Almost every residential standby generator up to about 26kW is air-cooled. These units are simpler, cheaper and fine for typical homes. Liquid-cooled generators, usually 30kW and up, run slower, quieter and cooler, and they’re built for long run times and very large homes. They cost much more and are sold through dealers, so they’re not covered here.

What installation involves

Expect a site visit, a load calculation, a permit application, a concrete or composite pad, a gas line from your meter or propane tank, an automatic transfer switch next to your main panel, and an inspection before the unit goes live. Your gas utility may need to upgrade the meter if the generator’s demand plus your furnace, water heater and range exceed its capacity. Lead times can stretch to weeks during storm season, so it’s best to buy and install in the off-season.

Features worth paying for

• Load management. Modules that temporarily shut off AC or other big loads let a smaller generator cover more of the house.
• Remote monitoring. Wi-Fi or cellular monitoring (Generac’s Mobile Link, for example) alerts you to faults and maintenance needs while you’re away.
• Quiet exercise mode. Low-speed self-tests are less disruptive to you and your neighbors.
• Corrosion-resistant enclosure. Important in coastal areas with salt air.
• Cold-weather kit. Battery and oil warmers help the generator start reliably in northern winters.

Standby vs. portable generator

Factor	Home standby	Portable
Starts automatically	Yes, within seconds	No, manual setup
Fuel	Natural gas or large propane tank	Gas cans or small propane tanks
Power	Whole home possible	Selected circuits
Cost	Much higher, plus installation	Lower
Home value	Often seen as an upgrade	None

FAQ

What size standby generator do I need for a 2,000 sq ft house?

Many 2,000 sq ft homes with one central AC fall in the 14–22kW range, often with load management. An electrician’s load calculation is the only way to be sure.

How long can a standby generator run?

On natural gas it can run as long as gas service continues, with breaks for maintenance during long outages. On propane, runtime depends on tank size and load.

Can I install a standby generator myself?

It’s not recommended. Installation involves gas plumbing, electrical work, permits and inspections, and DIY installation can void the warranty.

Is Generac the best standby generator brand?

Generac is the market leader with the largest installer network. Kohler, Briggs & Stratton and Champion are strong alternatives, and local service availability should guide your choice.