Home > All Products > Generators > Home Backup Generators > Centurion Series > 20kW-6258 whole house switch
Centurion 20kW with Whole House Switch

Centurion 20kW with Whole House Switch

Model #6258

Starting At

$4,549.00 MSRP MSRP Includes Transfer Switch and Not Installation Add to My Products

Centurion 20 kW Generator Features and Benefits

One of the most powerful air-cooled generators on the market today, the Centurion Series 20 kW automatic home standby generator can provide whole-house backup power for many homes.

Centurion 20 kW Generator <strong>Features and Benefits</strong>

Generac OHVI® Engine
Your Centurion Series generator might have to get you through days—or weeks—without utility power. Generac’s OHVI® engine, specifically designed for generator use, provides the reliability to power through the most severe outages.

True Power™ Technology
Best-in-class power quality with less than 5% total harmonic distortion means clean, smooth operation of your sensitive electronics and appliances.

Evolution™ Controller
The next generation of intuitive controllers featuring a multilingual, two-line LCD text display with color-coded, backlit buttons.

Certified for 18" Installation to the Home
Third-party certified to NFPA standards to be installed as close as 18” from the home’s exterior wall, provided it is located away from doors, windows, and fresh-air intakes, and unless otherwise directed by local codes.

Easy Installation
When combined with a Smart Switch, re-engineered connection points, and composite mounting pad that eliminates the need for a poured concrete base (unless specified by local codes), the Centurion Series 20 kW generator is easy to install.

Rated for Operation in Areas with Low Natural Gas Pressure
In areas with low natural gas pressure, the Centurion Series 20 kW generator can operate on natural gas pressures of only 3.5” of water column.

All-Weather Steel Enclosure
Our durable powder-coat finish helps make the sturdy, Galvanneal steel enclosure perfect for all weather conditions. It’s also able to withstand 150 mph winds.

Tool-less Fuel Conversion
Switch between natural gas and LP fuel in the field in a few seconds, without the need for any tools.

Quiet-Test™ Mode
Thanks to Quiet-Test, your Centurion Series home standby generator runs its weekly self-test at a lower RPM for only five minutes. Choose your schedule - weekly, bi-weekly or monthly.

Mobile Link™ Compatible
Take advantage of Generac’s Mobile Link cellular remote monitoring system and check on your generator’s status using your computer, tablet or smartphone, even when you are away. Sold separately.

Non-cellular remote monitoring options are also available for generator monitoring from inside the home.

24/7/365 Customer Support
Power outages don’t always occur during normal working hours. That’s why Generac’s customer care call center—right here in Wisconsin—provides support any time of day or night, all year long. Generac is standing by 24/7, every minute of every day, to answer your questions.

5-year Limited Warranty

Home Generator Buyer's Guide

Included with This Generator Bundle

Gain up to whole-house coverage through smart power management. If it is unlikely you will turn on every appliance at the same time (most people don’t), a smaller generator paired with a Generac Smart power management transfer switch provides whole-house coverage through a managed power solution. The process is simple - non-essential circuits are shed when the generator approaches maximum capacity to eliminate overload, then are cycled back on when essential circuits are satisfied. Give yourself a little more than just the basics without a substantial increase in your investment.

Download the Spec Sheet

Generac's Managed
Generac values your feedback!

When writing your review, please consider the following guidelines:

  • Prior to providing a review, refer to a product’s documentation to ensure that unit is being used and maintained properly
  • Alluding to issues incurred in the wake of negligent maintenance or improper use will void review submissions
  • Focus on your experience with the product and its features
  • Provide details about why you liked or disliked a product
  • Reviews submitted for products other than those listed will be rejected immediately
  • Any product reviews referencing independent authorized dealers, service providers, or retailers by name will NOT be posted. (Dealer reviews can be provided here)
  • All submitted reviews are subject to the terms set forth in our Terms of Use

We reserve the right not to post your review if it contains any of the following types of content or violates other guidelines:

  • Obscenities, discriminatory language, or other language not suitable for a public forum
  • Advertisements, “spam” content, or references to other products, offers, or websites
  • Email addresses, URLs, phone numbers, product serial numbers, physical addresses or other forms of contact information
  • Critical or spiteful comments on other reviews posted on the page or their authors

If you wish to share feedback with us about product selection, pricing, ordering, delivery, or other customer service issues, please do not submit this feedback through a product review. Instead, contact us directly.

Enjoy writing your review!

Rated 5 out of 5 by Best money ever spent This system is by far and away the best investment I've ever made I would Recommend to everyone go big or go home. This thing will run a small city May 5, 2016
Rated 5 out of 5 by Works great! Almost instant transition when the power goes out! When the power goes out, this product click right on and we have power back within seconds. Although we don't have everything connected to it, we have everything we need and forget that the power is off. No complaints! February 26, 2016
Rated 5 out of 5 by Peace of mind I recently had my generator installed with the transfer switch. Luckily I haven't needed it yet, but knowing it is there feels great! January 31, 2016
Rated 5 out of 5 by would recomend this product Had ice storm last February 2015 ran for 96 hours straight had no problems at all I would highly recommend this product. December 25, 2015
Rated 5 out of 5 by Best of any on the market So you are looking for a home backup power source, well after 3 years of research I found the CADILLAC of backup generstors, it is quiet, very reliable, affordable, goodlooking, blends into landscaape and will male your neighbors envious. So do your research and you will come up with the name, GENERAC. December 17, 2015
Rated 5 out of 5 by LMG. Love My Generac!! Having my Generac installed was the smartest move I have ever made. I never have to worry about losing my power. No more worries that the power may go out when I am not home. The peace of mind I have is a wonderful thing. If you are think gin of getting one. DO IT you will not regret it December 17, 2015
Rated 5 out of 5 by 20 KW runs the whole house We had the 20 KW unit installed in May 2014. It performs the weekly self test/run every week without fail. In addition I flip the main breaker maybe a couple times each month and the unit kicks in and runs the whole house. Last year during the summer a tornado/high wind event came through the area and the power went out for three hours but the Generac came on and ran two air conditioners, pool pump, pool heat pump, refrigerator and TV for three hours no problem. It eased the anxiety associated with the event. It worked just as well through the cold New England winter, starting and running with the cold weather battery warmer option. December 15, 2015
Rated 5 out of 5 by Best Deal for the Home I have had purchased 2 of the 20KW back up generators for both of my homes. One was natural gas and the other propane and both are reliable and effective operating generators at a very fair price. December 8, 2015
  • 2016-05-28 T09:46:28.095-05:00
  • bvseo_lps, prod_bvrr, vn_prr_5.6
  • cp-1, bvpage1
  • co_hasreviews, tv_269, tr_269
  • loc_en_US, sid_Cent6258, prod, sort_default
2 3 4 5 ... 28 next>>
  • bvseo_sdk, net_sdk,
  • CLOUD, getReviews, 0ms
Rated 4.8 out of 5 by 269 reviewers.
  • 2016-05-28 T09:46:28.095-05:00
  • bvseo_lps, prod_bvrr, vn_prr_5.6
  • cp-1, bvpage1
  • co_hasreviews, tv_269, tr_269
  • loc_en_US, sid_Cent6258, prod, sort_default
  • bvseo_sdk, net_sdk,
  • CLOUD, getAggregateRating, 16ms

The Generac Promise


Peace of mind.

And the power to live.

The Generac Promise means that our 8 – 22 kilowatt Guardian® Series home backup generators will give you peace of mind and the power to live. It means that we engineer and build them here in America*. It means we stand behind them with a strong 5-year limited warranty. We promise to continue to innovate, like with our new Mobile Link™ cellular monitoring system, so you’ll know the status of your generator, no matter where you are. And if you ever need to call, we’re standing by 24/7, every minute of every day, ready to pick up the phone right here in Wisconsin.

*Built in the USA using domestic and foreign parts.

We’ll back you up. We’re standing by. Count on it.

Generac Stock Ticker

  • NYQ
  • GNRC
  • $37.70
  • 5/27/2016 4:02 PM EST