The best portable generator for home backup: WEN DF8000X
Buy the WEN DF8000X ($623 at Amazon). This plan needs up to 7,060 starting watts and 4,060 running watts; it makes 8,000 and 6,500 on gasoline.
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.
We sized every generator we track for the moment the sump pump starts while the fridge, freezer and furnace are already running. That starting number decides the buy.
| Model | Running | Peak | Room over the hardest motor start | CO shutoff | Weight | Price | |
|---|---|---|---|---|---|---|---|
| Our pick |  WEN DF8000X | 6,500 W | 8,000 W | +940 W | CO Watchdog | 139 lb | $623 at Amazon |
| Quieter pick |  Champion 201520 10000W Tri Fuel Inverter | 7,750 W | 10,000 W | +2,940 W | CO Shield | 181 lb | $1,399 at Amazon |
Who this is for
You want the fridge, freezer, furnace and sump pump to keep going through an outage that lasts days, and you have a safe spot outdoors for an engine. You are willing to store fuel and to have an electrician fit an inlet so the generator can reach the things that are wired in.
How much generator you need
This plan needs up to 4,060 watts to keep running and up to 7,060 watts for the second a motor starts. The second number decides the buy: a generator sized only to the running total can stall when the sump pump kicks on while everything else runs. We size to the high end of every range, so an efficient fridge and a small pump leave you room to spare.
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, chest freezer, furnace blower and sump pump, plus lights, Wi-Fi and phones (this page’s plan) | 4,060 W | 7,060 W | 120 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, 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 |
|---|---|---|---|---|---|
| Gas-furnace blower | 24 | 400–1,200 | 30–70% | 2,880–20,160 Wh | 47% |
| Sump pump | 24 | 700–1,500 | 5–35% | 840–12,600 Wh | 30% |
| Chest freezer | 24 | 80–500 | 15–45% | 288–5,400 Wh | 13% |
| Refrigerator/freezer | 24 | 100–700 | see note | 1,300–3,100 Wh | 7% |
| Wi-Fi router and modem | 24 | 15–40 | 100% | 360–960 Wh | 2% |
| A few LED lights | 6 | 15–80 | 25–75% | 22–360 Wh | 1% |
| Phone charging and small USB devices | 4 | 10–40 | 20–60% | 8–96 Wh | 0% |
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 fridge, a chest freezer, a furnace blower, a sump pump, lights, Wi-Fi and phones, run against all 20 generators we track: 18 clear at least the best case, 0 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
Starts the whole plan, with a CO shutoff
$623 at Amazon, November 1, 20266,500 W continuous8,000 W peak139 lbgasoline, propane
The WEN DF8000X clears this plan's starting watts on gasoline, shuts off on carbon monoxide and has the L14-30R outlet an inlet cord plugs into. On propane it makes 5,850 running watts.
How we picked it: the lowest Amazon price among the generators that run this list and start its biggest motor, 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 fridge, a chest freezer, a furnace blower, a sump pump, lights, Wi-Fi and phones:
- 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 for the same plan
$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, so it runs quieter at light loads and makes cleaner power for electronics. It clears this plan's starting watts, 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 fridge, a chest freezer, a furnace blower, a sump pump, lights, Wi-Fi and phones:
- 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. Count the refills an outage of several days takes and buy fuel cans before the storm. Propane keeps for years; gasoline goes stale unless you treat it.
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.
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
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. Appliance figures are ranges, and your own fridge and pump may need less.
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. Good generators we could not price stay in the roster without a pick.
The competition
Every unit we track, run against the same plan.
Every unit on Amazon that clears at least the best case (10)
| 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 |
 Honda EU3000iS Inverter Generator | 2,800W | 3,000W | gasoline | $2,499 | Best case only |
 Champion 201513 6500W Inverter | 5,000W | 6,500W | gasoline | $999 | Best case only |
8 more clear it but have no verified bare-unit Amazon listing; the planner lists them.
What will not work, and why (0)
Every generator we track either clears this plan or is listed above as one we could not judge.
Questions people ask
What size generator do I need for home backup?
For a fridge, a chest freezer, a furnace blower, a sump pump, lights and Wi-Fi: at least 4,060 running watts and 7,060 starting watts. A 240-volt well pump needs a bigger one. The sizing table on this page shows each step and the generator that clears it.
Do I need a generator with a CO shutoff?
We only pick generators that have one. A CO shutoff stops the engine when carbon monoxide builds up near it. It does not make indoor use safe: run the generator outdoors, away from windows and doors, and keep battery CO alarms in the house. Westinghouse's WGen9500DF, the generator this page used to pick, has no CO sensor; the WGen9500DFc does.
Can I plug a generator into my house?
Not into a wall outlet. That sends power back down the utility line and can kill a line worker. A furnace blower or a sump pump that is wired in is reached through an inlet with an interlock, or a transfer switch, fitted by a licensed electrician. That is why the WEN DF8000X has the L14-30R outlet: it is the plug that inlet takes.
Other plans we sized
- Home backup
- Camping and road trips
- CPAP
- Refrigerator
- Sump pump
- Furnace
- Well pump
- 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