Quick answer: a Generac generator is the default whole house choice in the US, and the Guardian 22kW is the model most homes actually need. This guide compares every Generac generator line for house backup and what each Generac generator costs installed.
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Generac sells more whole house generators in the US than anyone else. That scale is a real advantage - the dealer network for parts and service is the densest in the industry, and five-year warranties are standard on the main lines - but it also means the catalog is confusing, with overlapping model names and frequent product refreshes. This guide sorts the lineup by what each line is actually for. For what size you need before picking a model, start with the generator size calculator.
Generac generator standby lines
Guardian series (8.5kW - 26kW). The core whole-house line, air-cooled, natural gas or propane. The 22kW Guardian (model 7043 and its Wi-Fi variants) is the single most-installed home standby in the country; the 18kW and 24kW variants bracket it for smaller and larger loads. Most Guardian units pair with Generac's own automatic transfer switches, sold separately or bundled depending on the SKU - check this before comparing prices, because an ATS adds $500-$1,500.
PowerPact (7.5kW). Generac's budget standby: a fixed 8-circuit package with an included 50A transfer switch. It covers essentials (furnace, fridge, sump pump, lights, internet) rather than the whole house, and costs roughly half of a Guardian 22kW installed. For gas-heated homes under about 2,000 sq ft, it is often all that is justified. Our standby vs portable guide covers who should stop here.
Ecogen (liquid-cooled, 25-60kW). For very large or all-electric homes where air-cooled units run out of headroom. Installation economics change at this size; treat it as a small commercial project.
What a Generac standby actually costs installed
Equipment for a Guardian 22kW typically runs $4,000-$6,000; realistic all-in installed cost lands between $10,000 and $14,000 once you add the transfer switch, electrical work, gas connection, and pad. The PowerPact installs for roughly $5,000-$7,000 all-in. Quotes vary enormously between installers - we have seen $3,800 spreads on identical jobs - so get three and compare line items. The full cost breakdown explains every line.
Generac's portable and inverter units
Generac also sells conventional portables (GP series), inverter portables (IQ), and the dual-fuel XD diesel line. These compete with Champion and Westinghouse rather than with Generac's own standby units. The portables matter to this guide mainly as the budget path: a Generac portable plus a transfer switch covers essentials at a third of standby cost.
Generac generator ownership realities
Standby units self-run about 12 minutes weekly for exercise. In quiet neighborhoods this is audible; most owners stop noticing within a month, but it is a fair question for your installer about placement. Yearly oil and filter service runs roughly $150-$300 on a service plan, and Generac's Mobile Link monitoring (included or optional depending on SKU) emails you status.
Output derates about 3% per 1,000 ft of altitude, so high-elevation homes should size up one class; the calculator handles this automatically. Note that low gas pressure in older neighborhoods can trip units even without weather triggers, so your installer should verify supply during quoting.
Generac generator vs the alternatives
Kohler is the closest peer: comparable outputs, five-year warranties, commercial-grade engines, better enclosure reputation, fewer dealers in some regions. Briggs & Stratton sits slightly cheaper with 3-5 year warranties. Champion is primarily the value-portable player. See the comparison table for side-by-side specs.
Where to buy
- Generac 7043 Guardian 22kW on Amazon
- Generac 7210 16kW on Amazon
- Generac 24kW on Amazon
- Generac 7626 XD5000E portable on Amazon
FAQ
How long do Generac whole house generators last? With yearly maintenance, standby units commonly run 20-30 years of standby duty (exercise cycles plus outage hours). Engine-hours life is far higher than what home use accumulates.
Can a Generac run on propane only? Yes. All Guardian and PowerPact units run on natural gas or propane; propane requires a tank sized for expected outage duration - roughly a week of half-load runtime from a 500-gallon tank for a 22kW unit.
How big of a Generac do I need for a 2,500 sq ft house? Most 2,500 sq ft gas-heated homes with central AC land on 16-22kW; all-electric homes may need more. Run your appliance list through the calculator rather than guessing from square footage.
Do Generac generators qualify for rebates? Some utility and state programs rebate standby installs with automatic transfer switches, especially in the Northeast and Gulf Coast. Ask your installer what applies locally; $500-$1,000 back is common where programs exist.
Bottom line
For most buyers the decision collapses to two Generacs: PowerPact if you need essentials, Guardian 22kW if you need the whole house. Size first, then buy the best local installer you can find - on installation quality, the installer matters as much as the badge.
