How to Choose the Perfect Whole House Generator: A Beginner's Guide

Power outages can happen at any time, leaving you in the dark and disconnecting you from essential services. A whole house generator provides peace of mind, but choosing the right one can feel overwhelming. This guide breaks down everything you need to know to make a confident decision.

Quick Tip: The average American home needs a 16-22kW generator to power essential systems during an outage.

5Top Brands Comparison
6Installation and Costs
7Maintenance Requirements
8Making Your Final Decision

What is a Whole House Generator?

A whole house generator (also called a standby generator) is like a backup power plant for your home. It automatically detects when your regular power goes out and starts up within seconds to keep your lights on, refrigerator running, and heating or cooling systems working.

How It Works

The generator sits outside your home (similar to an AC unit)
A transfer switch monitors your home's power supply
When an outage occurs, the switch signals the generator
The generator starts automatically and powers your home
When utility power returns, it switches back and shuts down

Key Components

Engine: Converts fuel into electrical power
Alternator: Produces the electricity
Transfer Switch: Safely connects to your home's electrical panel
Weather-Proof Housing: Protects all components
Control Panel: Manages operation and monitors status

Important: Unlike portable generators, whole house generators are permanently installed, connect directly to your home's electrical system, and start automatically during outages without you having to do anything.

Why You Might Need a Whole House Generator

Power outages are becoming more common across the US due to aging infrastructure, extreme weather events, and increased demand on the grid. Here's a look at when outages typically occur throughout the year:

Safety & Comfort

Keep heating, cooling, security systems, and medical devices running during outages. Protect your family from extreme temperatures and potential hazards.

Prevent Financial Loss

Avoid spoiled food, frozen pipes, flooded basements (from sump pump failures), and property damage. Maintain productivity if you work from home.

Peace of Mind

Relax knowing your home will continue running normally during extended outages. No need to worry about finding hotel rooms or relocating during emergencies.

Who Benefits Most from a Whole House Generator?

✓Families with young children or elderly members who are more vulnerable to temperature extremes
✓Households with medical needs requiring powered equipment (CPAP machines, oxygen concentrators, etc.)
✓Remote or rural homes that experience frequent or prolonged outages
✓Areas prone to extreme weather like hurricanes, ice storms, or high winds
✓Homes with sump pumps to prevent basement flooding during power outages
✓Remote workers who can't afford to lose internet connectivity

Sizing: How Much Power Do You Need?

Choosing the right size generator is crucial. Too small, and it can't handle your needs; too large, and you're wasting money on capacity you'll never use. Here's how to determine what size is right for you:

Common household appliances and their power requirements

Understanding Generator Sizing Terminology

Term	What It Means	Why It Matters
Kilowatt (kW)	A unit of power equal to 1,000 watts	Generator sizes are typically listed in kW (e.g., 16kW, 20kW, 24kW)
Running Watts	Power needed to keep appliances running	Determines the base load your generator must handle
Starting Watts	Extra power needed when motors first start up	Can be 2-3x higher than running watts for items like AC units
Load Management	Technology that prioritizes certain circuits	Allows a smaller generator to power more by cycling appliances

Common Generator Sizes for Homes

Size	Typically Powers
8-10kW	Essential circuits only (lights, refrigerator, select outlets)
14-16kW	Small to medium home with gas heat (no central AC)
20-22kW	Medium home with central AC or electric heat pump
24-30kW	Large home or homes with multiple AC units
30kW+	Luxury homes, all-electric homes, or homes with specialized equipment

How to Calculate Your Needs

List all appliances you want to power during an outage
Find running and starting watts for each item (check labels or manuals)
Add up all running watts to get your base load
Identify the appliance with the highest starting watts
Add the highest starting watts to your base load
Choose a generator with at least that capacity

Pro Tip: Many dealers offer free sizing consultations and will perform a detailed load calculation for your specific home.

Fuel Options Explained

The type of fuel your generator uses affects cost, reliability, and maintenance requirements. Here are the most common options:

Comparing Fuel Types

Fuel Type	Pros	Cons
Natural Gas	Unlimited supply via utility line No refueling needed Generally cleaner burning	Gas service may be disrupted in disasters Slightly less power output
Propane (LP)	Long shelf life (doesn't degrade) Clean burning Good for rural areas without natural gas	Requires tank installation Need to schedule refills Limited run time based on tank size
Diesel	Most fuel-efficient option Longer engine life Higher power output	Fuel can degrade over time Noisier operation More maintenance required

Popularity of Fuel Types

Residential generator fuel type distribution in the US

Real-World Advice: If natural gas is available in your area, it's typically the most convenient option for most homeowners. For areas without natural gas service, a propane generator with a large tank (250-500 gallons) provides good balance of convenience and reliability.

Top Generator Brands Comparison

Four manufacturers dominate the residential standby generator market. Each has strengths and weaknesses to consider:

Brand	Known For	Price Range	Warranty	Best For
Generac	Market leader, extensive dealer network	$3,000 - $6,000+	5-10 years depending on model	Homeowners wanting reliability and widespread support
Kohler	Premium quality, quieter operation	$3,500 - $7,000+	5 years/2,000 hours	Quality-focused buyers willing to pay more
Briggs & Stratton	Value pricing, engine expertise	$2,800 - $5,500+	4-6 years depending on model	Budget-conscious homeowners
Cummins	Commercial-grade durability, quietest operation	$4,000 - $7,500+	5 years/2,000 hours	Those wanting industrial quality and longer lifespan

Brand Selection Guidance

1
Choose Generac if you want the widest selection of models, sizes, and features with the largest support network.
2
Choose Kohler if you want premium quality, excellent power output, and don't mind paying more for a refined product.
3
Choose Briggs & Stratton if you're on a tighter budget but still want a reliable name-brand system.
4
Choose Cummins if you value industrial-grade construction, quieter operation, and plan to keep your home long-term.

Expert Advice on Brand Selection

"In my 20+ years of generator installations, I've found that the dealer's expertise and service quality often matters more than the brand itself. A well-installed, properly maintained Briggs & Stratton will outperform a poorly installed, neglected Kohler or Generac any day of the week."

— Mike Rodriguez, Master Electrician

Pro Tip: When selecting a brand, research local dealers first. A strong local service provider can make any brand a good choice for your home.

Installation and Costs

Installing a whole house generator isn't a DIY project. It requires professional electricians, plumbers, and sometimes concrete work. Here's what to expect:

Typical Installation Process

Site Preparation

Creating a proper pad (concrete or composite), ensuring proper clearances from windows, doors, and property lines.

Fuel Connection

Connecting to natural gas line or installing a propane tank. Must be done by a licensed professional.

Electrical Work

Installing the transfer switch, connecting to your electrical panel, and running wiring between components.

Generator Placement

Positioning the generator on the pad and connecting all components.

Permits and Inspections

Obtaining necessary permits and passing required inspections.

Testing

Thorough testing of the entire system before signing off on the installation.

Cost Breakdown

Component	Typical Cost Range
Generator Unit	$2,500 - $10,000+
Transfer Switch	$500 - $1,500
Installation Labor	$1,500 - $3,500
Electrical Work	$800 - $2,000
Gas Line Connection	$300 - $1,000
Concrete Pad	$300 - $800
Permits & Inspections	$200 - $500
Total Project Cost	$6,100 - $19,300+

Finding a Qualified Installer

The quality of installation significantly impacts your generator's performance and longevity. Here's how to find a good installer:

✓Look for factory-certified installers for your chosen brand
✓Check reviews and ask for references from previous installations
✓Verify proper licensing and insurance
✓Get at least 3 quotes for comparison
✓Ask about warranty support and ongoing maintenance options
✓Ensure they'll handle all permitting and inspection processes

Pro Tip: Be wary of significantly low-priced quotes. Quality installation is crucial for safety and reliability.

Maintenance Requirements

Like any mechanical system, generators require regular maintenance to operate reliably. Here's what you need to know:

Regular Maintenance Tasks

Task	Frequency	DIY or Pro?
Visual Inspection	Monthly	DIY
Oil & Filter Change	Annually or 100 hrs	Pro Recommended
Air Filter Check/Replace	Every 200 hrs	DIY Possible
Spark Plug Check	Annually	Pro Recommended
Battery Check/Replace	Every 2-3 years	Pro Recommended
Full System Inspection	Annually	Professional Only

Maintenance Costs & Contracts

Many dealers offer maintenance contracts that provide regular service and priority during emergencies:

Service Level	Typical Annual Cost	What's Included
Basic	$150-$300	Annual inspection, basic oil change
Standard	$300-$500	Basic + filters, spark plugs, priority service
Premium	$500-$800	All of the above + parts coverage, 24/7 emergency support

Pro Tip: Maintenance contracts often pay for themselves by extending generator life and preventing costly emergency repairs.

Remember: Regular maintenance is vital for ensuring your generator works when you need it most. A neglected generator may fail during an emergency—exactly when you're counting on it to perform.

Making Your Final Decision

With so many factors to consider, here's a step-by-step approach to finalizing your generator purchase:

Decision Checklist

Determine Your Power Needs

Calculate the total wattage required for essential systems and appliances. Remember to account for starting watts of motors and compressors.

Select Appropriate Size

Choose a generator that can handle your calculated load with at least 20% additional capacity for future needs.

Choose Fuel Type

Based on your location and preferences, select natural gas, propane, or diesel.

Research Brands & Models

Compare features, warranties, and prices across major manufacturers that fit your requirements.

Find Qualified Dealers

Research local dealers with good reviews and manufacturer certifications.

Get Multiple Quotes

Request detailed quotes from at least three dealers, including installation and maintenance options.

Consider Total Cost of Ownership

Factor in purchase price, installation, fuel costs, and maintenance over a 10-15 year period.

Make Your Selection

Choose the option that best balances your needs, budget, and long-term reliability.

Common Buying Mistakes to Avoid

✗Undersizing your generator – This is the most common and serious mistake
✗Choosing solely on price – Quality and support matter more long-term
✗Neglecting to check local codes – Some areas have noise or placement restrictions
✗Skipping professional installation – This is never DIY-friendly and affects safety
✗Forgetting about maintenance – Plan for upkeep from the beginning
✗Overlooking noise considerations – Check decibel ratings if you have close neighbors
✗Not considering future needs – Your power requirements may increase over time

Questions to Ask Before Buying

Q
What size generator do I need to run my entire home?
Q
What happens to the generator when I'm on vacation?
Q
How loud is the generator during operation?
Q
What kind of warranty comes with the generator?
Q
How quickly will the generator respond to a power outage?
Q
What is the expected lifespan of this generator?

Ready to Protect Your Home?

Find qualified generator dealers in your area who can provide personalized quotes and professional installation.

FIND LOCAL DEALERS

Conclusion

A whole house generator represents a significant investment in your home's comfort, safety, and resilience. By understanding the key factors we've covered in this guide—from sizing and fuel options to brands and maintenance—you're now equipped to make an informed decision.

Remember that the perfect generator is the one that meets your specific needs, budget, and local conditions. Take your time with this decision, get multiple quotes from reputable dealers, and focus on quality installation.

With the right generator in place, you'll gain invaluable peace of mind knowing that when the lights go out for everyone else, your home will remain a safe, comfortable haven for you and your family.

Frequently Asked Questions

How long do standby generators typically last?

With proper maintenance, a quality standby generator can last 15-20 years for residential use. Factors affecting lifespan include frequency of use, maintenance schedule, and environmental conditions. Commercial-grade models like Cummins may last even longer.

Will my generator turn on automatically when the power goes out?

Yes, whole house generators are designed to start automatically when they detect a power outage through the automatic transfer switch. This typically happens within 10-30 seconds of losing utility power, depending on the brand and model.

How much fuel does a standby generator use during an outage?

Fuel consumption varies based on generator size and load. As a general guideline, a 20kW natural gas generator running at full load consumes approximately 210-245 cubic feet per hour. For propane, the same generator would use about 2.3-2.8 gallons per hour. At half load, these numbers would be roughly half.

Do I need to be home to operate the generator?

No, whole house generators operate completely automatically whether you're home or away. Many models also offer smartphone apps that allow you to monitor your generator's status remotely.

Will a generator increase my home's value?

Yes, studies suggest that adding a whole house generator can increase home value by 3-5%, with an average ROI of about 54% of the installation cost. In areas prone to frequent power outages, the value-add can be even higher. More importantly, it can be a significant selling point that differentiates your home in a competitive market.