The best generator for a well pump: WEN DF8000X
Buy the WEN DF8000X ($623 at Amazon). It makes 120/240 V, and its 8,000 starting watts on gasoline clear the 6,780 this plan can need when the pump starts with the fridge running.
It has CO Watchdog, which shuts the engine off if carbon monoxide builds up, and the L14-30R outlet that an electrician-fitted inlet takes.
A well pump is the hardest start in most homes, and it is wired in at 240 volts. So the generator needs 240 volts, enough starting watts for the pump, and an outlet that an electrician's inlet can take.
| Model | Running | Peak | Room over the hardest motor start | CO shutoff | Weight | Price | |
|---|---|---|---|---|---|---|---|
| Our pick |  WEN DF8000X | 6,500 W | 8,000 W | +1,220 W | CO Watchdog | 139 lb | $623 at Amazon |
| Quieter pick |  Champion 201520 10000W Tri Fuel Inverter | 7,750 W | 10,000 W | +3,220 W | CO Shield | 181 lb | $1,399 at Amazon |
Who this is for
You are on a well, so when the power goes the water goes with it: no tap, no shower, no second flush. You want the pump back, along with the fridge and a few lights, for about a day, and you have somewhere outdoors, well clear of the house, for a machine to sit and run.
How much generator you need
Two numbers come out of this plan; one decides everything. Keeping it all running takes 815 to 2,780 watts, which is the easy part. Starting the pump takes 2,115 to 6,780 watts for a split second, and a machine sized to the running total does not run the pump weakly, it stalls. A well pump is the hardest start in an ordinary house, and that surge is the number you shop on.
Generator size by what you run
The first row is this page’s plan. The other rows are other plans, smaller and bigger, so you can see where your house fits.
| What you run | Running watts | Starting watts | Volts | Lowest-priced generator that clears it |
|---|---|---|---|---|
| Fridge and a 240 V well pump, plus lights (this page’s plan) | 2,780 W | 6,780 W | 120/240 V | WEN DF8000X (6,500 W running, 8,000 W peak) $623 at Amazon |
| Fridge and chest freezer, plus lights, Wi-Fi and phones | 1,360 W | 3,560 W | 120 V | WEN DF8000X (6,500 W running, 8,000 W peak) $623 at Amazon |
| Fridge, chest freezer, furnace blower and sump pump, plus lights, Wi-Fi and phones | 4,060 W | 7,060 W | 120 V | WEN DF8000X (6,500 W running, 8,000 W peak) $623 at Amazon |
| Fridge, chest freezer, furnace blower, sump pump and a 240 V well pump, plus lights, Wi-Fi and phones | 6,060 W | 10,060 W | 120/240 V | Westinghouse WGen9500DFc (9,500 W running, 12,500 W peak) $1,049 at Amazon |
| Fridge, chest freezer, furnace blower, sump pump, 240 V well pump, window air conditioner and microwave, plus lights, Wi-Fi and phones | 11,110 W | 15,110 W | 120/240 V | No portable generator we can price clears it. This is a job for a standby generator sized by an electrician. |
Running watts: every appliance at the high end of its range, all on at once. Starting watts: that, plus the biggest motor starting. Appliance figures are on our appliance pages. A generator in the last column must clear both numbers on gasoline, shut itself off when carbon monoxide builds up, make 240 V where a row needs it, and have a 30 A or 50 A locking outlet when a row has a wired-in appliance (a furnace blower, a sump or well pump), because that outlet is how an electrician-fitted inlet reaches the house. Among those, it is the lowest Amazon price. For a whole house: what size generator for 200 amp service.
Adjust this plan to your house. Change the hours or the loads and the picks are re-scored here, with the same planner and the same maker figures.
Where the energy goes, load by load
| Load | Hours | Running watts | share of time running | Energy | Share of worst case |
|---|---|---|---|---|---|
| Well pump | 24 | 700–2,000 | 2–15% | 336–7,200 Wh | 67% |
| Refrigerator/freezer | 24 | 100–700 | see note | 1,300–3,100 Wh | 29% |
| A few LED lights | 8 | 15–80 | 25–75% | 30–480 Wh | 4% |
Refrigerator energy comes from ENERGY STAR’s certified models plus our allowance for the station and real use, from an efficient new fridge to an old, big one: see how much power a fridge uses. For every other load, energy = running watts × share of time running × hours, at each end of the range. The right-hand end of every row is what the plan is sized on.
A well pump, a refrigerator and a few LED lights for 24 hours, run against all 20 generators we track: 13 clear at least the best case, 5 do not, and 2 could not be judged (a missing maker figure or an unclear recall status). Every figure is from the maker’s own page or manual; nothing here was tested by us. The method.
Our pickWEN DF8000X
240 volts, starts the pump, CO shutoff
$623 at Amazon, November 1, 20266,500 W continuous8,000 W peak139 lbgasoline, propane
The WEN DF8000X makes 120/240 V, clears this plan's starting watts on gasoline, and shuts off on carbon monoxide. Its L14-30R outlet is the plug an inlet cord takes.
How we picked it: the lowest Amazon price among the generators that run this list and start its biggest motor, make 240 V, shut themselves off when carbon monoxide builds up, and have the 30 A or 50 A locking outlet an inlet cord plugs into.
Price as of November 1, 2026; the listing for this model on its own.
A well pump, a refrigerator and a few LED lights for 24 hours:
- Running loadyes, even in the worst case
- Starting surgeyes, even in the worst case
What you give up: Noise and clean power: it is an open-frame generator, louder than an inverter, so put a TV or computer on a surge protector.
Figures from wenproducts.com, captured October 13, 2026; recall screen: no published recall names this exact model (screened 2026-10-13) (how we screen, CPSC).
Quieter pickChampion 201520 10000W Tri Fuel Inverter
Quieter inverter that makes 240 volts
$1,399 at Amazon, November 1, 20267,750 W continuous10,000 W peak181 lbgasoline, propane, natural gas
The Champion 201520 10000W Tri Fuel Inverter is an inverter generator that makes 120/240 V, so it runs quieter at light loads and makes cleaner power. It starts this pump, has CO Shield and has the L14-30R outlet for an inlet.
Price as of November 1, 2026; the listing for this model on its own.
A well pump, a refrigerator and a few LED lights for 24 hours:
- Running loadyes, even in the worst case
- Starting surgeyes, even in the worst case
What you give up: Weight: at about 181 lb it is a wheeling job, not a carry.
Figures from championpowerequipment.com, captured October 13, 2026; recall screen: no published recall names this exact model (screened 2026-10-13) (how we screen, CPSC).
Past the first tank
A generator runs as long as you feed it. The maker rates the WEN DF8000X at 10.5 hours at half load on a full tank. The pump is idle most of the day, so a tank lasts longer than the starting watts suggest. Count the refills an outage takes and buy fuel cans before the storm.
Hooking it up safely
Four rules that are not optional
Outdoors only, at least 20 feet from the house, exhaust pointed away. Never in a garage, even with the door open. Fit battery-powered CO alarms indoors; a CO shutoff on the generator is not a substitute.
Never plug it into a wall outlet. That backfeeds the utility line and can kill the worker restoring your power. Wired loads need a transfer switch or inlet installed by a licensed electrician: which transfer switch fits your generator.
Keep it dry. Running it wet is an electrocution hazard; the makers sell covers for a running generator.
Fuel: never refuel a running or hot engine, and store fuel outside living space in containers made for it. The full safety boundaries.
How a generator reaches a wired-in pump
The pump is wired in, so there is no cord to move and no socket to use. An electrician can fit an inlet box outside with an interlock on your panel, or a transfer switch, and the generator's locking outlet plugs into that inlet. Both are permit work, and the makers of these parts say they must be fitted by a licensed or qualified electrician.
Never feed the house through a wall outlet. It sends power back down the utility line and can kill the crew restoring it. The generator stays outdoors, away from windows, doors and vents.
Buying it right
A search for these models returns bundles, sibling models and the same unit under two prices. We link only a listing whose own title states the unit on its own with its exact battery and output. Match the model number on the label to this page. How we check a listing.
- WEN DF8000X: we link the model on its own, checked November 1, 2026. We turned down 9 other listings (bundles, sibling models, repeats); see which and why.
- Champion 201520 10000W Tri Fuel Inverter: we link the model on its own, checked November 1, 2026. We turned down 9 other listings (bundles, sibling models, repeats); see which and why.
What this page can’t promise
This page sizes machines against a modelled well pump, not against yours. Horsepower, depth and the control box set the surge, and the label in your well house is the only place that number lives. If it sits above our range, everything here moves up a size.
Nothing here was tested by us. Every figure is the maker's own, from its product page or manual, and each model page links the source. We pick only generators sold on Amazon as the unit on its own, with a price checked within a day and no published recall naming the model.
The competition
Every unit we track, run against the same plan.
Every unit on Amazon that clears at least the best case (9)
| Model | Running | Peak | Fuel | Amazon price | Verdict |
|---|---|---|---|---|---|
 Champion 201169 6500W Tri Fuel | 6,500W | 8,125W | gasoline, propane, natural gas | $999 | Clears it |
| WEN DF8000X | 6,500W | 8,000W | gasoline, propane | $623 | Clears it |
 Westinghouse WGen7500DFc | 7,500W | 9,500W | gasoline, propane | $949 | Clears it |
| Champion 201520 10000W Tri Fuel Inverter | 7,750W | 10,000W | gasoline, propane, natural gas | $1,399 | Clears it |
 Westinghouse WGen9500DF | 9,500W | 12,500W | gasoline, propane | $999 | Clears it |
 Westinghouse WGen9500DFc | 9,500W | 12,500W | gasoline, propane | $1,049 | Clears it |
 Champion 201438 10000W Tri Fuel | 10,000W | 12,500W | gasoline, propane, natural gas | $1,260 | Clears it |
 DuroMax XP13000HX | 10,500W | 13,000W | gasoline, propane | $1,399 | Clears it |
 Champion 201513 6500W Inverter | 5,000W | 6,500W | gasoline | $999 | Best case only |
4 more clear it but have no verified bare-unit Amazon listing; the planner lists them.
What will not work, and why (5)
- 5 lack the 240 V output the plan needs
Every one, with the figure that fails, is in the planner when you enter this plan.
Questions people ask
What size generator do I need for a well pump?
For a well pump, a fridge and lights: at least 2,780 running watts and 6,780 starting watts, at 240 volts. That covers a large pump at the hard end; a small pump needs less, and the label on your pump tells you. Add a furnace and a sump pump and you need more: see the sizing table on this page.
Will a 120-volt generator run a well pump?
Not a 240-volt pump, and many well pumps are wired for 240 volts. A 120-volt generator cannot make 240 volts, and no adapter changes that. Check the voltage on the pump's listed, then buy a generator that makes 240 volts, like the WEN DF8000X.
Can I plug the generator into the house to run the pump?
Not through a wall outlet. That sends power back down the utility line, can kill a line worker, and breaks the National Electrical Code. The pump is reached through an inlet with an interlock, or a transfer switch, fitted by a licensed electrician, usually with a permit.
Other plans we sized
- Home backup
- Camping and road trips
- CPAP
- Portable generators
- Refrigerator
- Sump pump
- Furnace
- Power station or generator: which do you actually need?
- How to connect a power station to your house
- Solar panels for a power station: how many, and how long
- Expansion batteries: what an extra battery for a power station actually does
WEN DF8000XOur pick
$623 at Amazon