Costco Honeywell 18kW Generator Review: The Best Value for Most Homes

Published: February 21, 2025 | By Michael Johnson, Home Energy Solutions Expert

Honeywell 18kW Home Standby Generator with Transfer Switch

When the power goes out, having a reliable backup generator can mean the difference between comfort and chaos. The Honeywell 18kW Home Standby Generator sold at Costco has become a popular choice for homeowners seeking peace of mind during outages—but is it worth the investment?

This comprehensive review explores whether this generator provides the right amount of power for a typical home, its value compared to similar models, and the real customer experience—including my own—with Costco's famous customer service when issues arise.

Quick Facts: Costco Honeywell 18kW Generator

Current Price: $5,199

Includes: Automatic transfer switch (added value)

Bonus: Additional 5% off with Costco credit card

Shipping: Free delivery included

True Identity: Generac-manufactured with Honeywell branding

App Compatibility: Works with Generac app

Service Compatibility: Serviceable by Generac dealers

Warranty: Backed by Costco's customer satisfaction guarantee

Compare Before You Buy

Looking at multiple options? This review will help you understand if the Costco Honeywell unit is right for your home's power needs.

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What Makes This Generator Special?

A Generac in Disguise

While branded as Honeywell, this generator is actually manufactured by Generac—one of the most trusted names in home backup power. You're getting Generac engineering with Honeywell aesthetics.

Transfer Switch Included

Unlike many competitors, this package includes the automatic transfer switch—a critical component that typically costs $500-1,000 when purchased separately.

Costco's Legendary Service

Beyond the manufacturer's warranty, you get Costco's famous customer satisfaction guarantee—a safety net that's proven valuable for many buyers, including myself.

Is 18kW Enough? Understanding What This Generator Can Power

For most average-sized homes (2,000-3,000 sq ft), an 18kW generator hits the sweet spot between power capacity and cost. Here's what you can expect to run simultaneously:

Room/Area	Appliances You Can Run	Notes
Kitchen	Refrigerator, microwave, dishwasher, lights, most kitchen outlets	Can handle electric range, but may require load management
Climate Control	Central AC (up to 5 tons), furnace fan, electric heat pump	Manages the high starting load of AC compressors
Basement/Utility	Sump pump, well pump, water heater, security system	Critical systems during power outages fully covered
Home Office	Multiple computers, Wi-Fi, printers, charging stations	Keep working remotely during extended outages
Entertainment	TVs, gaming consoles, audio equipment, streaming devices	Stay entertained during long outages
Multiple Bathrooms	Lights, exhaust fans, electric toilets, one electric water heater	All bathroom functionality maintained

Common Household Appliance Power Needs

With 18kW (18,000 watts), you can run multiple high-demand appliances simultaneously.

Pro Tip: The 18kW size is ideal for most homes, but if you have multiple air conditioning units or a very large home (4,000+ sq ft), you might need to consider a larger unit or implement load management.

Value Comparison: Is the Costco Price Worth It?

At $5,199, the Costco Honeywell generator represents significant value when you consider what's included and the alternatives:

Feature	Costco Honeywell 18kW	Direct from Honeywell	Comparable Generac
Generator Price	$5,199	$5,601.95	$5,099
Transfer Switch	Included	Not included	Not included
Transfer Switch Cost	$0 (included)	$600-900	$600-900
Shipping	Free	$200-400	Varies by dealer
Costco Credit Card Discount	5% ($260 savings)	N/A	N/A
Total Effective Cost	$4,939	$6,401-6,901	$5,899-6,199
Return Policy	Costco Satisfaction Guarantee	Varies	Varies by dealer

Historical Price Perspective

While the Costco Honeywell generator represents good value today, it's worth noting that the unit has been downsized over the years. Previous models offered 20kW capacity at a similar price point. The current 18kW model reflects the trend of "shrinkflation" we've seen across many consumer products.

Despite this reduction, 18kW remains sufficient for most households, and the value proposition—especially with the included transfer switch—remains strong.

My Personal Experience: Costco's Customer Service in Action

Like many major purchases, the path isn't always perfect. When my Honeywell generator was delivered, I discovered it had a leaking oil tank—an issue that could have been a nightmare with another retailer.

Here's how Costco handled the situation:

I contacted Costco customer service about the damaged unit
They arranged pickup of the damaged generator within 48 hours
A complete replacement was scheduled and delivered
Costco provided a partial refund for the inconvenience—without me even asking
The entire process was handled with minimal effort on my part

This experience reinforced a key value proposition: when buying a complex, expensive piece of equipment, the retailer's commitment to customer satisfaction matters just as much as the product itself.

Important Considerations Before You Buy

Installation Is On You

Costco delivers the generator to your home (curbside), but installation is your responsibility. This is a major difference from purchasing through a dealer who typically handles installation.

The generator weighs approximately 450 pounds and requires professional electrical and gas connections. You'll need to hire a qualified installer—and some installers may decline to work on units they didn't sell.

Seamless Generac Compatibility

Despite the Honeywell branding, this is essentially a Generac generator. This provides several advantages:

Compatible with the Generac app for monitoring
Uses standard Generac parts for maintenance
Can be serviced by any authorized Generac technician
Benefits from Generac's extensive dealer network

The Installation Reality: What to Expect

While Costco delivers the generator, you'll need to arrange and manage the installation process:

Installation Component	Typical Cost Range	Notes
Concrete Pad	$300-600	Required for stable mounting and proper operation
Electrical Connection	$1,000-2,000	Licensed electrician required, includes transfer switch installation
Gas Line Installation	$500-1,200	Licensed plumber needed for natural gas or propane connection
Permits	$200-500	Electrical, gas, and sometimes zoning permits required
Generator Placement	$300-500	Moving 450lb unit from delivery location to installation site
Total Installation	$2,300-4,800	Varies significantly based on complexity and location

Important: Some generator dealers may decline to install units they didn't sell. Be sure to line up qualified installation professionals before purchasing. Always obtain multiple installation quotes to ensure competitive pricing.

Finding the Right Installer

Since installation isn't included, you'll need to find qualified professionals:

Authorized Generac Dealers

Ask if they'll install customer-supplied units. Some will, but may charge a premium compared to installing units they sell.

Licensed Electricians

Many qualified electricians can handle generator installations. Look for those with specific generator experience.

Installation Services

Some areas have specialized generator installation services that will handle the entire process from permitting to final testing.

Key Takeaways

The Costco Honeywell 18kW generator provides exceptional value with the included transfer switch
18kW is sufficient for most average homes (2,000-3,000 sq ft) to maintain essential functions and comfort
This is a Generac-manufactured unit with Honeywell branding, offering compatibility with Generac's ecosystem
Costco's customer service provides valuable protection if issues arise
Plan for $2,300-4,800 in additional installation costs beyond the purchase price
Remember to factor in 5% additional savings when using your Costco credit card

Final Verdict: Is It Worth It?

For most homeowners seeking reliable backup power, the Costco Honeywell 18kW generator represents excellent value. The combination of Generac engineering, included transfer switch, free shipping, and Costco's customer service makes this a compelling option despite the need to arrange your own installation.

If you're comfortable managing the installation process separately and want to save $1,000+ compared to dealer packages, this generator should be at the top of your consideration list.

Ready to Secure Your Home's Power?

The Costco Honeywell 18kW generator provides peace of mind during power outages at a competitive price point.

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Remember: Orders with your Costco credit card save an additional 5%.