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Generac standby generators in Colorado

Generac is the default standby generator in Colorado: it's what most installers sell and service. Size it for altitude. Generac's own spec sheets cut output about 3.5% per 1,000 feet, so a 26 kW unit loses roughly a fifth of its power in Denver, and natural gas ratings already start lower than propane.

Headquarters: Waukesha, Wisconsin, USA
Where it’s made: Generac says its generators and engines are 'engineered and assembled in the USA' using domestic and foreign parts.
Warranty: 5-year limited, generator and transfer switch
Altitude: About 3.5% less output per 1,000 ft
Cold weather: Battery and oil heaters recommended where it regularly drops below 32°F
Colorado installers: 57 of 83 in our October 2026 survey list Generac

Models for home backup

Next-generation air-cooled home standby, 22/24/26/28 kW (G-Force 1000 engine, built-in cellular; announced Jan 22, 2025, shipping from 2H 2025)

Natural gas output	22 kW model: 21; 24 kW model: 22.5; 26 kW model: 24; 28 kW model: 25
Propane output	22 / 24 / 26 / 28
Fuel	Natural gas or LP (field-selectable gaseous)
Transfer switch	Sold separately or bundled (bundles G007325-0, G007326-0, G007328-0, G007329-0 include a 200 A service-rated, 2-pole 120/240 V NEMA 3R ATS with integrated surge protection, part A0005902810)
Sound	67 dB(A) at 23 ft at normal load; 55 dB(A) in low-speed Quiet-Test exercise
Notes	Manufacturer calls the 28 kW the most powerful air-cooled home standby on the market. New Electronic Fuel and Ignition Control (EFIC) for motor starting; can start a 5-ton A/C per the announcement.

Next-generation air-cooled home standby, 10/14/18 kW (built-in cellular)

Propane output	14 kW model: 14; 18 kW model: 18
Fuel	Natural gas or LP
Transfer switch	Available with or without ATS (e.g. G0073230 14 kW 'with Transfer Switch'); ATS has built-in whole-home surge protection
Engine	18 kW: G-Force 800

Guardian Series Wi-Fi models (prior generation, still listed: 14/18/22/24/26 kW, e.g. G0072900 26 kW, G0070420 22 kW)

Fuel	Natural gas or LP
Transfer switch	Sold bare or with whole-house or 16-circuit transfer switch depending on SKU
Connectivity	Wi-Fi (Mobile Link)

Warranty

5-year limited warranty on every Generac home standby generator; the 22-28 kW spec sheet says it covers the generator and transfer switch.

Altitude

'Maximum power decreases approximately 3.5% for each 1,000 ft (304.8 m) above sea level.' Also about 1% per 10°F above 60°F. At Denver (~5,280 ft), that is roughly an 18% reduction.

Cold weather

No single cold-weather kit for the new 22-28 kW line. Spec sheet lists a battery heater and an oil heater, both recommended if temperatures regularly fall below 32°F (0°C), and a breather heater for extreme cold with heavy icing, recommended if temperatures regularly fall below 0°F (-18°C). Product pages cite 'improved cold start performance' and a sloped roof plus rear air intake to cut snow and ice intrusion. No generator operating temperature range is published on the spec sheet.

Monitoring and the app

Mobile Link app. New-generation units have built-in cellular connectivity (no home Wi-Fi needed, so it can keep reporting during a grid outage if the cellular network is up). Product pages say 'free Mobile Link' but also footnote that some features (real-time updates, maintenance alerts) need a Mobile Link premium subscription. Older Guardian models use Wi-Fi, which depends on the home router having backup power.

Recalls

2021-07-29: Generac and DR 6500 W and 8000 W portable generators (XT8000E, XT8000EFI, GP6500, GP6500E, GP8000E, HomeLink 6500E, DR PRO 6500M/6500E), about 321,160 units in the US. Recall 21-173. Hazard: An unlocked handle can pinch fingers against the frame when the unit is moved (finger amputation and crushing hazard). CPSC notice

2022-11-10: Reannouncement of the July 2021 recall of the same 6500 W/8000 W portable models, with a new repair kit. Recall 23-040. Hazard: Finger amputation and crushing hazard from the unlocked handle. CPSC notice

2023-09-14: Generac GP15000E and GP17500E portable generators and DR Power PROXL17500DP, about 64,000 units. Recall 23-288. Hazard: The fuel tank may not vent properly through the rollover valve. Pressure can build and fuel can be expelled when the tank is opened (fire and burn hazard). CPSC notice

All three recalls are Generac portable generators. No CPSC recall of Generac home standby generators since 2021 was found.

What a Colorado homeowner should know

At 5,000-6,000 ft, the published 3.5%-per-1,000-ft derate takes a meaningful bite. A 26 kW unit (24 kW on natural gas at sea level) delivers noticeably less in Denver, so size with derate in mind.
Natural gas output is lower than LP on most sizes (e.g. 28 kW model: 25 kW NG vs 28 kW LP). Most Front Range homes would be on NG.
New line integrates with ecobee thermostats and Generac PWRcell batteries; built-in cellular works without home internet.

Generac is sold and installed through certified installers. Tell us what you need and we’ll connect you with one who installs it in your area.

Get an install quote Size my backup

Reviewed October 29, 2026 from manufacturer documents and CPSC records. Specs and terms change; confirm with the manufacturer or your installer. Colorado Peak Power is independent of Generac.

Sources

generac.com /residential-products/standby-generators/gaseous/standby-generator-26k
manfilemode-generacsoa.generac.com /api/manualfiles/G0072600/A0005151077/0
generac.com /residential-products/standby-generators/gaseous/standby-generator-14k
generac.com /residential-products/standby-generators/gaseous/standby-generator-18k
generac.com /residential-products/standby-generators/
generac.com /residential-products/standby-generators/gaseous/standby-generator-28k
cpsc.gov /Recalls/2021/Generac-Recalls-Portable-Generators-Due-to-Finger-Amputa
cpsc.gov /Recalls/2023/CPSC-Reannounces-Recall-of-Generac-Portable-Generators-A
cpsc.gov /Recalls/2023/Generac-Recalls-Portable-Generators-Due-to-Serious-Fire-
altenergymag.com /story/2025/01/generac-unveils-the-most-powerful-air-cooled-home-stand