Generac standby generators: what the specs tell you
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Quick answer
Generac's air-cooled home standby generators run on natural gas or propane and start automatically through a transfer switch when the power fails. Two 22 kW bundles show what to compare. Model 7325 is rated 22 kW on propane and 21 kW on natural gas, and burns 2.45 gallons of propane an hour at half load. Model 7043 includes a 200 amp outdoor smart switch and lists under 5% total harmonic distortion. Both carry Generac's 5 year limited warranty. Check the fuel use against your propane tank and the connectivity terms before you buy.
How a Generac standby generator works
Think of a Generac standby unit as a permanent engine-generator parked beside the house on a pad, plumbed to your gas meter or propane tank. When utility power drops, its transfer switch senses the loss, the engine starts on its own, and the switch moves your circuits onto generator power within seconds. When the grid returns, it hands the load back and shuts down. Between storms the unit tests itself: Generac's Quiet-Test mode spins the engine at a lower speed for a five or twelve minute run, which keeps the weekly check quieter and lighter on fuel.
Two 22 kW bundles compared
| Model 7325 bundle | Model 7043 bundle | |
|---|---|---|
| Running watts | 22,000 | 22,000 |
| Propane rating | 22 kW | 22 kW |
| Natural gas rating | 21 kW | See spec sheet |
| Controller | Power Zone 200 | Evolution, with LCD display |
| Connectivity | Built-in cellular Mobile Link, premium subscription required | Mobile Link |
| Transfer switch | Bundled | 200 amp NEMA 3R outdoor smart switch |
| Weight | 451 lb | 466 lb |
| Warranty | 5 year limited | 5 year limited |
Model numbers matter. Similar 22 kW bundles differ in controller, connectivity and switch. Confirm the exact model on the quote you receive.
Fuel use: plan your propane tank
Generac lists the 7325's fuel use as 2.45 gallons of propane an hour at 50% load and 3.71 gallons an hour at full load. On natural gas at full load it uses 311 cubic feet an hour.
That adds up. A full day at half load on propane is about 59 gallons (2.45 times 24). If you heat with propane too, the generator and furnace draw from the same tank during a winter storm. Ask your propane supplier to size the tank for the longest outage you want to ride out. Natural gas homes avoid refilling, but your installer must confirm the meter and gas line can supply the generator.
Size: is 22 kW right for you?
Generac's own advice is to size from the electrical load you need to carry, not the floor area. In its guide, 22 kW is the usual whole-home choice around 2,000 square feet, smaller homes often fit 10 to 18 kW, and large homes with several AC units move up to 22 to 28 kW. If you only want the essentials, a 14 kW Guardian bundle paired with a 16-circuit switch is the lighter option. Our whole house generator guide explains essential circuits versus whole-home coverage.
Questions to ask before you sign
- Which exact model and switch? Get the model number in writing.
- Natural gas or propane rating? Size from the fuel you have. The 7325 is 1 kW lower on natural gas.
- Gas supply? Is the meter and line big enough at full load?
- Permit and inspection? Generac's sizing guide says professional installation is required and most jurisdictions require an electrical permit and an inspection.
- Monitoring cost? The 7325's cellular Mobile Link requires a premium subscription.
- Maintenance? Generac says to check oil every 24 hours of use during an outage and follow its maintenance schedule.
What to look for when you buy
Generac 22 kW home standby bundle (model 7325)
Best for: About 2,000 sq ft homes wanting whole-home backup on gas or propane
Generac lists 22 kW on propane and 21 kW on natural gas, 2.45 gallons per hour of propane at half load, a bundled transfer switch and a 5 year limited warranty.
Watch out: Cellular Mobile Link requires a premium subscription, and it weighs 451 pounds.
See options on Amazon (opens Amazon in a new tab)Generac 22 kW bundle with 200 amp smart switch (model 7043)
Best for: Homes that want the Evolution controller and a 200 amp outdoor switch
Generac lists 22,000 running watts, a 200 amp NEMA 3R aluminum smart switch, the Evolution controller with LCD, under 5% THD and a 5 year limited warranty.
Watch out: It weighs 466 pounds. Confirm the natural gas rating on the spec sheet for your variant.
See options on Amazon (opens Amazon in a new tab)Generac 14 kW Guardian with 16-circuit switch (model 7224)
Best for: Essential-circuit backup for smaller homes
Rated 14 kW on either propane or natural gas, this Guardian bundle ships with a 16-circuit switch so only the circuits you pick are backed up.
Watch out: Large loads like central air may not fit. Have your installer check.
See options on Amazon (opens Amazon in a new tab)Battery-operated carbon monoxide alarm
Best for: Every level of a home with a standby generator
Any fuel-burning generator makes carbon monoxide, and Ready.gov advises working CO detectors on every level of the home.
Watch out: Test it monthly and replace it on the maker's schedule.
See options on Amazon (opens Amazon in a new tab)Questions people ask
- How does a Generac generator work?
- An automatic transfer switch watches utility power. When it fails, the generator starts by itself and the switch moves the house onto it within seconds, then hands back to the grid when power returns.
- How much propane does a Generac 22kW use?
- Generac lists the 7325 at 2.45 gallons per hour at half load and 3.71 gallons per hour at full load.
- Does Generac Mobile Link cost extra?
- On the 7325 bundle, Generac says cellular Mobile Link requires a premium subscription. Check the terms for your exact model.
- What warranty does a Generac standby generator have?
- Generac says every standby generator comes with a 5 year limited warranty.
Sources
- Home Standby Generator, 22kW, Transfer Switch Bundle (7325), Generac
- 22kW Home Generator with Transfer Switch (7043), Generac
- What Size Generator Do I Need? Sizing Guide, Generac
- Home Generators for Backup Power & Peace of Mind, Generac
- 14kW Guardian Series Home Generator with Transfer Switch (7224), Generac
- Power Outages, Ready.gov