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What will a 4,000 watt generator run

22 of 25 common home loads run on their own with a generator of 4,000 watts. Whether a pump or an air conditioner starts up depends on starting watts, which run about 5,000.

22 of 25home loads it runs alone
5,000 Wstarting watts, a typical portable's 125% surge
Well pump, 1 hpbiggest motor it starts
0.38 galgasoline an hour at half load

Loads that run on a 4,000 watt generator

LoadRunningStartingVerdict
Refrigerator400 W1,200 Wruns
Chest or upright freezer500 W1,000 Wruns
Sump pump, 1/3 hp800 W1,600 Wruns
Sump pump, 1/2 hp1,050 W2,150 Wruns
Well pump, 1/2 hp1,000 W2,000 Wruns
Well pump, 1 hp2,000 W4,000 Wruns
Window AC, 5,000 BTU600 W1,200 Wruns
Window AC, 10,000 BTU1,200 W2,400 Wruns
Electric water heater4,500 Wno surgewon't run
Electric dryer6,000 Wno surgewon't run
Electric range, one burner2,400 Wno surgeruns
Dishwasher2,400 Wno surgeruns
Microwave1,200 Wno surgeruns
Washing machine1,000 W2,300 Wruns
Space heater1,500 Wno surgeruns
TV, 32 to 55 in400 Wno surgeruns
LED lights, 10 bulbs150 Wno surgeruns
Ceiling fan75 Wno surgeruns
Window fan200 Wno surgeruns
CPAP, no heated humidifier60 Wno surgeruns
CPAP with heated humidifier120 Wno surgeruns
Internet router and modem20 Wno surgeruns
Home security system40 Wno surgeruns
Phone and laptop chargers100 Wno surgeruns
EV charger, Level 2, 32 A7,680 Wno surgewon't run

A load works if its running watts stay within 4,000 W and its start stays within 5,000 W; "tight" means running above 3,200 W. Look at your own model's label to find its starting watts. Champion's published chart lists these wattages at the top of the range. The appliance wattage chart lists more loads.

1 more of these loads runs on a 5,000 watt generator, and the electric water heater is one of them.

Loads run together

TogetherRunningPeak at startVerdict
Fridge, freezer, lights, router, TV1,470 W2,270 Wruns
Fridge, 1/2 hp sump pump, lights, router1,620 W2,720 Wruns
Fridge, 1 hp well pump, microwave, lights3,750 W5,750 Wwon't run
Fridge, window AC 10,000 BTU, lights, TV2,150 W3,350 Wruns
Fridge, space heater, microwave, lights3,250 W4,050 Wtight

Motors starting one at a time let running watts add up, so only the biggest starting wattage counts on top.

Gasoline used per hour

0.38 galan hour at half load, about $1.62
0.65 galan hour at full load, about $2.77
9 hon a typical 3.4 gal tank at half load

$4.269 a gallon is the EIA US average price for gasoline. Keep a portable generator outside, 20 ft from the house, and hook it up with an interlock kit or a transfer switch, not a dryer outlet.

Sizes: 3,500 W generator 5,000 W generator All sizes