040591 12KW – 6 Year Warranty


Our dealer exclusive Fortress standby generator line comes with great additional features. We offer the longest premium level of protection in the industry with a 6-year parts, labor and travel warranty. These generators come equipped with oil warmers for when the temperature drops to -1°C or lower.

Now 60% quieter* and 50% smaller than our old 12 kW, you don't have to compromise your home's curb appeal to get the protection of automatic backup power. With its sleek, compact profile, the 12 kW Home Standby Generator adds new dimension to “Powering More for Less.” Perfect for smaller to medium-sized homes, the new 12 kW generator combined with our Symphony® II Power Management System allows you to meet the power needs of your whole house, (including up to two 4-ton air conditioners).

*Based on no load sound power.

Managed Whole House Power
Not all appliances are powered equally. Some, such as your central air conditioner, electric clothes dryer, electric stovetop, oven, or whirlpool tub, require a large amount of power to start up or operate properly.

The Symphony® II Power Management orchestrates these high-demand appliances with lower-demand items to give you true whole-house power with a smaller, more affordable generator.
Fortress 12 kW Standby Generator System
Engine BrandBriggs & Stratton
Engine SeriesVanguard™
Engine Displacement627
OperationFully Automatic
Voltage (V)120/240V AC, Single Phase, 1.0 pf
Alternator TypeComputer Friendly
Weekly ExerciserYes
Battery/Battery ChargerYes
Overcrank ProtectionYes
Hour MeterYes
Diagnostic Alerts With Remote System StatusLow Oil Shutdown, Engine Does Not Start, Low Frequency, Engine Overspeed, Low Voltage, Low Battery Voltage, Oil Temp High, Transfer Switch Fault
Length (in)28
Width (in)26
Height (in)37.2
Weight (lbs)318
Warranty (Product)***6 Year Parts, Labor & Travel Limited Warranty
Running Watts LP12,000
Fuel Consumption Cubic Feet per Hour at Half Load LP50% load = 2.36 gal/hr
Running Watts NG11,000
Fuel Consumption Cubic Feet per Hour at Half Load NG50% load = 119 ft³ /hr
Running Amperage NG45.8
Running Amperage LP50
Warranty Consumer Product Info6 Year Parts, Labor & Travel Limited Warranty


*NG = Natural Gas; LP = Liquid Propane.

**Fuel consumption rates are estimated based on normal operating conditions at 1/2 load. Generator operation may be greatly affected by elevation and the cycling operation of multiple electrical appliances - fuel flow rates may vary depending on these factors.

***See Operator's Manual for complete warranty details