Best Generators for Well Pumps
The best generators for well pumps, with sizing for 1/2 to 1.5 HP 240V pumps, dual-fuel and inverter picks, and transfer switch tips.
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The short answer
Most residential well pumps run on 240 volts and need two to three times their running watts for a split second at startup, so the generator has to deliver both 240V and a big surge. For a typical 1/2 to 1 HP pump plus essential household circuits, a 9,000–13,000 peak-watt dual-fuel generator with a 240V outlet is the practical range. Our top pick is the Westinghouse WGen9500DF; for larger pumps or more of the house, choose the DuroMax XP13000EH. If you want clean, quiet 240V power, the Honda EU7000iS inverter is the premium option.
How much generator does a well pump need?
Well pumps are induction motors, and motors draw a large inrush current to get moving. Industry sizing guides commonly put that startup surge at roughly 3 to 5 times the running amps. The exact figures are on your pump’s nameplate or in the control box, so check there first. Typical ranges published by water-system suppliers look like this:
| Pump size | Approx. running watts | Approx. starting watts | Generator to look at |
|---|---|---|---|
| 1/2 HP | About 1,000–1,500 | About 2,000–3,000 | 5,000–7,500W with 240V |
| 1 HP | About 1,500–2,000 | About 4,000–6,000 | 7,500–10,000W with 240V |
| 1.5 HP | About 3,000 | About 7,500–10,000 | 10,000–13,000W with 240V |
Then add whatever else needs to run during an outage: refrigerator, freezer, furnace blower, lights, a water softener (which draws little) and phone chargers. A common rule is to add 20–30% headroom above your total. A soft-start device on the pump can cut the startup surge substantially and may let you get by with a smaller generator; ask your well contractor whether one suits your pump.
Our picks at a glance
| Pick | Model | Fuel | Key feature | Best for | Amazon |
|---|---|---|---|---|---|
| Best overall | Westinghouse WGen9500DF | Gas / propane | 12,500 peak watts, remote electric start, transfer-switch ready | 1/2–1 HP pump plus essentials | Check price |
| Best for big pumps | DuroMax XP13000EH | Gas / propane | 13,000 peak watts, electric start, transfer-switch ready | 1–1.5 HP pumps, more circuits | Check price |
| Best value | Champion 9375-Watt Dual Fuel | Gas / propane | Electric start, 3-year warranty | Smaller pumps on a budget | Check price |
| Best inverter | Champion 11,000-Watt Inverter | Gas / propane | Inverter power, quieter operation, electric start | Pump plus sensitive electronics | Check price |
| Premium pick | Honda EU7000iS | Gas | 120/240V inverter, up to 16 hours runtime (rated) | Quiet, reliable 240V for smaller pumps | Check price |
Peak and running ratings are manufacturer figures; generators produce less on propane than on gasoline. Always verify that the specific model and outlet configuration you buy delivers 240V.
1. Westinghouse WGen9500DF — Best overall
The WGen9500DF is one of the most popular home-backup portables for good reason. It is rated at 12,500 peak watts, runs on gasoline or propane, and has remote electric start, so you are not yanking a pull cord in a storm. It is built to connect to a transfer switch or interlock kit, which is how a 240V well pump should be powered: through the home’s panel, not an extension cord. That surge capacity comfortably covers the startup of a typical 1/2 to 1 HP pump with room for a fridge, freezer and lights.
Good to know: a version with a CO sensor, the WGen9500DFc, adds automatic shutoff if carbon monoxide builds up, and is worth the small premium.
Check the Westinghouse WGen9500DF on Amazon →
2. DuroMax XP13000EH — Best for larger pumps
If your pump is 1 HP or larger, or you want to run the pump, a well-pressure tank, a furnace and kitchen circuits together, step up to the 13,000-watt DuroMax. It is dual fuel, has electric start, and is marketed as transfer-switch ready for whole-home backup. The extra surge headroom is what matters with deep-well pumps: undersized generators can stall or trip when the pump kicks on while other loads are running.
Good to know: this is a big, heavy, loud open-frame generator. Plan a permanent outdoor spot and a short, heavy-gauge cord or inlet run. The XP13000HX is a closely related alternative if it is easier to find in stock.
Check the DuroMax XP13000EH on Amazon →
3. Champion 9375-Watt Dual Fuel — Best value
Champion’s 9375-watt dual-fuel portable is a well-reviewed, budget-friendly choice for a 1/2 HP pump plus essentials. It has electric start and Champion backs it with a 3-year limited warranty and a US-based support line, which owners frequently mention. A version with CO Shield auto-shutoff is also available.
Good to know: with a 1 HP or bigger pump, this size gets tight once other motors (fridge, freezer, sump) start at the same time. Stagger loads or size up.
Check the Champion 9375-Watt on Amazon →
4. Champion 11,000-Watt Inverter — Best inverter for well pumps
Large inverter generators used to be rare, but Champion’s 11,000-watt dual-fuel inverter brings inverter power to home-backup size. Inverters produce cleaner power, which is friendlier to computers, smart thermostats and modern appliance boards, and they are quieter than open-frame generators. It has electric start and runs on gas or propane.
Good to know: inverter surge capacity is often tighter than an open-frame generator with the same headline number. Compare your pump’s starting watts against the inverter’s rated starting watts before buying.
Check the Champion 11,000-Watt Inverter on Amazon →
5. Honda EU7000iS — Premium pick
The EU7000iS is Honda’s largest portable inverter, with 120/240V output, electric start and a rated runtime of up to 16 hours. Honda generators have a strong reputation for longevity and quiet running, so this is the one for buyers who want backup they will barely hear. It suits smaller well pumps and essential circuits rather than whole-home loads.
Good to know: it is gasoline only and costs significantly more than open-frame competitors. A 50-state California-compliant version is sold separately.
Check the Honda EU7000iS on Amazon →
Buying checklist
- 240V output. Look for a 120/240V twist-lock (L14-30R) or 50A (14-50R) outlet. A 120V-only generator cannot run most well pumps.
- Starting watts, not just running watts. Compare the pump’s nameplate starting load against the generator’s peak rating, with other motors running.
- Transfer switch or interlock. A well pump is hard-wired. Have a licensed electrician install a transfer switch or interlock kit and power inlet. Never backfeed through a dryer outlet.
- Dual fuel. Propane stores for years without going stale, which helps for long outages.
- CO safety. Choose a model with CO auto-shutoff when possible.
- Soft starter. Ask your well installer about a soft-start kit if you want to run a smaller generator.
Safety: carbon monoxide and placement
Run any portable generator outdoors only, at least 20 feet from the house with the exhaust pointed away from doors, windows and vents. Never run one in a garage, basement or crawlspace, even with the door open. Install battery-powered CO alarms inside the home. Let the engine cool before refueling.
FAQ
What size generator do I need to run a well pump?
For a typical 1/2 HP 240V pump, about 5,000–7,500 watts with a 240V outlet. For a 1 HP pump plus household essentials, 9,000–12,500 peak watts is a safer range. Larger pumps need more.
Can I run a well pump on a 120V generator?
Only if the pump itself is a 120V model, which is uncommon. Most submersible and jet well pumps are 240V and need a generator with 240V output.
Will an inverter generator run a well pump?
Yes, if it has 240V output and enough starting watts. Large inverters like the Honda EU7000iS or Champion’s 11,000-watt model can, but always check the surge rating against your pump.
Do I need a transfer switch for a well pump?
Practically, yes. Well pumps are hard-wired to the panel, so the safe, code-compliant way to power one is a transfer switch or interlock kit installed by an electrician.
How do I find my well pump’s horsepower?
Check the label on the pressure-switch control box or the pump paperwork. If the pump is submersible, the control box in the basement or well house usually lists HP and voltage.
