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Generac 18 kW home standby generator
The Short AnswerThe Generac 18 kW air-cooled home standby generator (model 7259) is rated at 18 kW on propane and 17 kW on natural gas. Middle of the range in the lineup we install. Southern Power Generators installs it with an automatic transfer switch across metro Atlanta, and James Hill, a licensed Master Electrician, confirms it's the right size for your home first.
18 kWon propane
17 kWon natural gas
65 dBAat 23 ft, running
5 yearsGenerac limited warranty
Is it the right size?
Middle of the range
Often a fit for covering much of an average home, depending on your A/C units and whether your appliances are gas or electric.
Every home is different. The number of A/C units, electric appliances and pumps all change the answer, so James confirms the size on a free site visit before you decide.
| Generac model | 7259 (generator) |
| Rated output, propane | 18 kW |
| Rated output, natural gas | 17 kW |
| Engine | Generac G-Force 800, 817 cc |
| Sound at 23 ft, normal operation | 65 dBA |
| Sound at 23 ft, quiet weekly test | 55 dBA |
| Size (L x W x H) | 46.4 x 26.3 x 30.7 in |
| Weight | About 426 lb |
| Fuel use at full load | 235 cu ft/hr natural gas · 2.87 gal/hr propane |
| Monitoring | Cellular connectivity with Generac's Mobile Link app |
| Generac warranty | 5-year limited |
Specs from Generac's air-cooled standby generator spec sheets (Rev D, August 2026). Ratings are Generac's maximum power ratings and drop at high temperatures and altitudes. Generac may update its specs, so check Generac's site for the latest. See it on Generac.com.
Questions about the 18 kW
Your generator questions, answered
What can a 18 kW generator run?
Often a fit for covering much of an average home, depending on your A/C units and whether your appliances are gas or electric. The real answer depends on your home, so James sizes it on the free site visit.
How much does a 18 kW Generac cost installed?
Every home is different. The price depends on the generator size, how far it sits from your gas meter and electrical panel, whether you need a propane tank, any panel work, and what your permit requires. After a free site visit, James gives you a written estimate that spells out the equipment, installation and extras. No hidden fees and no pressure.
Does the 18 kW run on natural gas or propane?
Both. Generac rates it at 18 kW on propane and 17 kW on natural gas.
Does it come with a transfer switch?
Every standby generator we install comes with an automatic transfer switch, matched to your panel.
Get a generator quote
Ready before the next storm?
Tell us a little about your home and we'll call or text you to set up a free site visit.
Call or text404-593-6308
Emailjames@southernpg.com
Office2637 White Oak Dr, Decatur, GA 30032
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