Best Whole House Standby Generator in 2025: Tested and Reviewed

Power outages can strike without warning—leaving your home dark, cold, and disconnected. That’s where a reliable whole house standby generator becomes a true lifesaver. But with so many options on the market, how do you know which one is actually worth your investment? In this guide, we’ve tested and reviewed the best whole house standby generators to help you make an informed decision. Whether you need to keep the lights on during a storm or run your entire household during an extended outage, we break down the top models for performance, noise level, fuel efficiency, and overall value.

List of the Best Whole House Standby Generator:

Check out the detailed reviews below.

1. Generac Guardian 24kW Home Standby Generator

The Generac Guardian 24kW Home Standby Generator with 200 Amp Transfer Switch sets a new standard for residential backup power solutions. Delivering a powerful 24,000 watts with less than 5% total harmonic distortion, it ensures clean and stable electricity for sensitive appliances. This generator, proudly engineered and assembled in the USA, features Generac’s exclusive G-Force Engine, designed for durability and reduced maintenance. When outages strike, the unit activates automatically, running on natural gas or LP fuel for uninterrupted comfort and security. Its all-aluminum enclosure resists corrosion, while the 200 Amp transfer switch guarantees whole-house coverage.

Furthermore, integrated Wi-Fi and Mobile Link technology offer seamless remote monitoring via smartphone or computer. Homeowners can stay informed of maintenance schedules and performance status, wherever they are. Backed by a robust 5-year limited warranty and supported by a vast nationwide dealer network, the Guardian 24kW offers reliability and peace of mind. Though installation requires a certified electrician, the design includes installer-friendly features for quicker setup.

Key Features, Pros, and Cons

Key Features:

• 24kW True Power Technology ensures clean, stable power
• Mobile Link Wi-Fi allows remote performance monitoring
• 200 Amp outdoor-rated transfer switch for whole-house backup
• Durable all-aluminum enclosure resists harsh conditions
• Made in USA with robust G-Force Engine for reduced maintenance

Pros:

• Seamless automatic operation during outages
• Clean power suitable for sensitive electronics
• Strong warranty and nationwide support
• Efficient, low-maintenance engine
• Remote monitoring adds convenience

Cons:

• Installation requires certified electrician

2. Westinghouse 28000 Watt Home Backup Generator

The Westinghouse 28000 Peak Watt Home Backup Portable Generator delivers exceptional power and reliability for residential use. With an impressive 28,000 peak watts and 20,000 running watts, it easily supports large homes and essential appliances during outages. Featuring a robust 999cc V-Twin OHV engine with a cast iron sleeve, this gas-powered unit offers durability and performance. Thanks to its 17-gallon fuel tank, it runs up to 11 hours at 50% load, ensuring extended backup without frequent refueling.

User convenience is a priority. The generator includes a remote start key fob, push-button electric start, and an easy-access control panel. It also boasts multiple outlets, including 30A and 50A transfer switch ready ports, making it versatile for whole-home backup. Safety is enhanced with automatic low oil shutoff, a CO sensor, and rubber outlet covers. Meanwhile, the digital readout keeps users informed of runtime, volts, and frequency.

Key Features, Pros, and Cons

Key Features:

• 28,000 peak and 20,000 running watts for whole-house coverage
• Remote electric start with auto choke for easy operation
• Multiple outlets including 30A and 50A transfer switch ready ports
• CO sensor and automatic low oil shutdown for safety
• 11-hour runtime at 50% load on a 17-gallon fuel tank

Pros:

• Extremely powerful for residential backup
• Remote start and easy-access control panel
• Comprehensive safety features
• Long runtime per tank
• Versatile outlet options

Cons:

• Gasoline-only fuel limits flexibility

3. Westinghouse 18000 Watt Dual Fuel Home Backup Generator

The Westinghouse 18000 Peak Watt Dual Fuel Home Backup Portable Generator offers exceptional versatility and power for residential backup needs. With up to 18,000 peak watts on gasoline and 16,000 peak watts on propane, it easily supports major appliances during outages. Running at 14,500 watts on gas and 13,000 watts on propane, it ensures continuous power when you need it most. Its ultra-duty 713cc V-Twin OHV engine delivers up to 11 hours of runtime at 50% load using the 10.5-gallon fuel tank, reducing refueling interruptions.

This generator features dual fuel capability, allowing homeowners to switch between gasoline and propane based on availability. Starting is effortless with electric start and a remote key fob, while the VFT Data Center displays volts, frequency, and run time. Safety is prioritized through automatic low oil shutdown, a CO sensor, and rubber outlet covers. Additionally, the generator offers flexible connectivity with multiple outlets, including transfer switch ready L14-30R and RV-ready 14-50R ports, plus USB ports for electronics.

Key Features, Pros, and Cons

Key Features:

• 18,000 peak watts (gas) and 16,000 peak watts (propane) for reliable backup
• Dual fuel capability for flexibility during emergencies
• Electric and remote start with easy push-button ignition
• CO sensor, low oil shutdown, and rubber outlet covers for safety
• Up to 11-hour runtime on gasoline with 10.5-gallon fuel tank

Pros:

• Powerful and dual fuel capable
• Remote and electric start for convenience
• Extensive outlet options including USB
• Strong safety features
• Portable despite size

Cons:

• Not ideal for ultra-quiet environments

4. DuroMax XP13000HXT Portable Generator

The DuroMax XP13000HXT Tri Fuel Portable Generator delivers robust and flexible power for both residential and commercial needs. Featuring 13,000 watts of peak power, this generator easily runs large homes during outages. Its advanced 500cc OHV engine ensures strong, stable performance across all fuel types. Thanks to Tri Fuel capability, users can choose between gasoline, propane, or natural gas. This versatility makes it easy to operate during emergencies when fuel availability may vary.

Starting is simple with the push-button electric start or remote start, offering convenience from a distance. The user-friendly front-facing interface allows for effortless fuel switching. Furthermore, the generator includes multiple outlets, such as a transfer switch-ready 50A outlet, which powers essential appliances simultaneously. Safety is a top priority with the integrated CO Alert, which automatically shuts down the unit if harmful carbon monoxide levels are detected.

Key Features, Pros, and Cons

Key Features:

• 13,000 watts peak power with tri fuel (gasoline, propane, natural gas) capability
• 500cc OHV engine for durable, high-output performance
• Push button and remote start for easy operation
• Transfer switch-ready 50A outlet supports whole-home use
• CO Alert system ensures user safety

Pros:

• Tri fuel flexibility for fuel choice
• Powerful enough for large homes
• Easy start options including remote control
• Integrated CO protection
• User-friendly fuel switching interface

Cons:

• Some reports of starting issues

5. DuroMax XP13000EH Dual Fuel Portable Generator

The DuroMax XP13000EH Dual Fuel Portable Generator offers powerful and flexible home backup power. Delivering up to 13,000 peak watts, this generator runs on both gasoline and propane, giving homeowners fuel flexibility during outages. With 10,500 running watts, it can support essential appliances, HVAC systems, and more. The electric start with push-button ignition ensures easy operation, while the intuitive front-facing control panel allows quick fuel switching.

Designed for durability, the XP13000EH features a heavy-duty all-metal frame and 100% copper windings for enhanced reliability and longer lifespan. Its transfer switch-ready 50A outlet makes it ideal for whole-home backup, while multiple outlet types ensure compatibility with RVs and job sites. Safety is prioritized with low oil shutdown and a CO sensor to protect users from harmful fumes. Despite weighing 234 pounds, the unit is easy to move with its no-flat tires and foldable handle.

Key Features, Pros, and Cons

Key Features:

• 13,000 peak watts and dual fuel flexibility (gasoline or propane)
• 500cc DuroMax engine with electric push-button start
• Transfer switch-ready 50A outlet for whole-home backup
• Heavy-duty metal frame and 100% copper windings for durability
• CO sensor and low oil shutdown for safety

Pros:

• Dual fuel capability offers fuel choice
• Electric start for easy operation
• Powers entire homes and RVs
• Rugged build with copper windings
• Easy fuel switching interface

Cons:

• Not ultra-quiet for sensitive environments

How to Choose the Best Whole House Standby Generator?

When the lights go out and the fridge stops humming, one thing becomes crystal clear: power is everything. A whole house standby generator isn’t just a luxury anymore—it’s peace of mind in uncertain times. Whether you live in a storm-prone area or simply want to prepare for the unexpected, choosing the right generator can be a game-changer.

Why a Whole House Standby Generator?

Before diving into specs, let’s talk about why you might need one. Unlike portable generators, a whole house standby generator is permanently installed and automatically powers your home when the grid goes down. No cords. No fuel cans. Just seamless backup power for everything—from your HVAC system to your Wi-Fi router.

When we had a three-day blackout last winter, our standby generator kicked in within seconds. The heater stayed on, the food didn’t spoil, and honestly, it felt like magic. That experience made me realize how vital choosing the right generator really is.

Start with Your Power Needs

First things first: How much power do you actually need? To avoid overspending—or undersizing—make a list of the appliances and systems you want to keep running. These might include:

• HVAC units
• Refrigerator/freezer
• Lights and outlets
• Medical equipment
• Internet/router
• Sump pump
• Washer/dryer

Add up the total wattage required. Most whole house generators range between 12kW to 24kW, but don’t guess—use an online calculator or ask an electrician for a load assessment. For example, a 20kW generator can comfortably support a 2,500 sq. ft. home with essential appliances.

Fuel Type: What’s Best for Your Area?

Standby generators typically run on natural gas, propane, or diesel. Here’s how to decide:

• Natural Gas: Best for urban or suburban areas with gas lines. It’s convenient and never needs refueling.
• Propane: Great for rural areas without gas lines. You’ll need a tank and refills, but it burns clean.
• Diesel: Less common for residential use, but powerful and efficient. Consider only if you already have a diesel system in place.

If I had to choose again, I’d still go with natural gas—no fuss, no interruptions.

Consider Automatic Transfer Switch (ATS)

An Automatic Transfer Switch is the unsung hero of generator systems. It senses a power outage and automatically starts your generator—no action needed. Some models even offer smart load management, prioritizing appliances to avoid overloading.

Look for UL-listed ATS models compatible with your generator size. Trust me, you don’t want to be fumbling in the dark trying to manually power your home.

Noise Level Matters More Than You Think

Generators aren’t silent, but some are whisper-quiet compared to others. A typical generator operates between 60–70 decibels—about the level of a normal conversation. For suburban living, look for low-noise models or ones with sound-dampening enclosures. Your neighbors (and your ears) will thank you.

Budget Wisely, but Don’t Cut Corners

A reliable whole house generator can range from $7,000 to $15,000+, including installation. While it’s a big investment, think of it as insurance. The cost of replacing spoiled food, hotel stays, and frozen pipes can add up fast.

If budget is tight, consider smaller models with load management—they’ll power your essentials without breaking the bank.

Frequently Asked Questions When Selecting the Best Whole House Standby Generator

1. What is the best whole house standby generator?

The best whole house standby generator depends on your home’s size, power requirements, and location. Choosing the best one means balancing wattage, fuel type, brand reliability, and professional installation quality.

2. How many watts does a whole house generator need to power a typical home?

A typical home needs a generator between 14,000 to 24,000 watts (14–24 kW) to power all essential appliances and systems. For a smaller home (under 2,000 sq. ft.), 14–18 kW may be sufficient. Larger homes with multiple HVAC systems and high-energy appliances may require 20–24 kW or more. It’s best to calculate your total load using a wattage calculator or consult an electrician to determine exact needs.

3. What fuel type is best for a standby generator?

The best fuel type depends on availability and convenience. Natural gas is ideal if you have access to municipal gas lines—it’s clean, reliable, and requires no on-site storage. Propane is a great alternative for rural areas, offering clean combustion and good storage life. Diesel is more efficient for high-power needs but usually used in commercial or off-grid situations. Most homeowners choose natural gas for ease and automatic refueling.

4. How long can a whole house standby generator run?

Whole house generators can run indefinitely, as long as they have a steady fuel supply. Natural gas models can run continuously during extended outages because they’re connected to utility gas lines. Propane and diesel models are limited by tank size—typically running for 24 to 72 hours on a full tank. Always follow manufacturer guidelines for maintenance intervals during long runtimes.

5. Are standby generators noisy?

Modern standby generators are much quieter than older models. Most operate between 60–70 decibels, similar to a normal conversation or dishwasher. Brands like Kohler and Cummins are known for quieter engines and insulated enclosures. For neighborhoods with noise restrictions, choosing a low-noise model is important.

6. Can a standby generator power the entire house or just essentials?

It depends on the generator’s size and how it’s configured. Larger generators (20–24 kW and above) with an Automatic Transfer Switch (ATS) can power your entire home, including central HVAC, kitchen appliances, and electronics. Smaller units may only support critical circuits unless paired with a load management system that prioritizes usage based on real-time demand.

7. How much does it cost to install a whole house standby generator?

Installation typically costs between $2,000 to $6,000, depending on site conditions, electrical work, gas line connection, and permit requirements. The total cost—including the generator—ranges from $7,000 to $15,000+. Getting quotes from licensed installers ensures accurate pricing and code compliance.

8. Do I need a professional to install a standby generator?

Yes, professional installation is strongly recommended and often required to meet local codes and ensure warranty coverage. Installing a standby generator involves complex electrical connections, fuel line installation, and securing permits. Certified electricians and plumbers ensure the system is safe, reliable, and properly configured.

9. How often does a standby generator need maintenance?

Most manufacturers recommend maintenance every 6–12 months or after every 100–200 hours of use. This includes oil changes, air filter replacements, and checking battery levels. Many brands offer maintenance kits, and some installers provide annual service contracts to keep the unit in top shape.

10. Will a standby generator increase my home’s value?

Yes, installing a standby generator can increase your home’s resale value and appeal—especially in regions prone to power outages. It signals preparedness and reduces the inconvenience of future disruptions. Real estate experts report that homes with backup power often sell faster and at a higher price.

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