by Generac
Generac Guardian 18kW with Transfer Switch
18 kW standby generator
Key specifications
- Rated output, propane
- 18 kW
- Rated output, natural gas
- 17 kW
- Fuel
- Dual fuel (NG / LP)
- Phase
- Single-phase
- Transfer switch
- Included
- MSRP (starting)
- $6,769
- Dimensions
- 46.4 x 26.3 x 30.7 in
- Weight
- 426 lb
- Warranty
- 5 years
Unverifiable specs are omitted, not estimated. See sources below for what we can defend.
Fuel use
| Fuel | Half load | Full load |
|---|---|---|
| Propane | 1.65 gal/hr | 2.87 gal/hr |
| Natural gas | 164 ft³/hr | 235 ft³/hr |
On propane, a 500-gallon tank filled to 80% holds about 400 gallons. That runs the Generac Guardian 18kW with Transfer Switch for about 242 hours (10.1 days) nonstop at half load, or about 139 hours (5.8 days) at full load. See how much propane a generator uses for other tank sizes.
On natural gas, the gas line and meter have to deliver the full-load figure, 235 ft³/hr, even if the generator rarely runs that hard. Installers size the pipe to it.
Sources
Every spec above traces back to one of these citations.
- Generac product page — Standby Generator 18kW with Transfer Switch (G0073240) · checked July 2026
- Generac product page: Standby Generator 18kW with Transfer Switch (G0073240) (specifications table) · checked September 2026
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