Best Generator for Sump Pump

If the power goes out, you can only rely on a battery backup system for a certain period of time. After that, you are out of luck. When the power goes out for days, there is no way your battery backup system can keep your basement dry.

For events like these, you will need portable generators to guard your basement against flooding by keeping the sump pump running at all times. When the power goes out, and you have recurring water issues, you will need the best generator for sump pump to keep that pump going.

A 12V backup sump doesn’t have the power needed to keep your basement dry during a bad storm. Even a good sump pump running on a deep cycle battery will be out of power sooner than you might expect.

If you live in an area that is prone to power outages, having multiple backup systems, including a small, portable generator, is a really good idea for a variety of reasons.

What Need To See Before Buying The Best Sump Pump Generator?

Now, there are a couple of things you will need to take into consideration before you invest in a portable generator for a sump pump.

Size Matters

To determine how much power is needed for a sump pump, here are some numbers:

A 1/3 HP sump pump needs a starting power of 1300 watts and a running power of 800 watts. This will vary depending on the brand. A 1/2 HP sump pump needs 2150 starting watts and 1050 running watts.

You will need to double these wattages if you want to run two sump pumps with a small portable generator. These numbers are just for example. In short, If there is a power outage, you’ll need a generator with enough wattage to keep your sump pumps running.

It is possible to use a mid-sized generator (3,000-5,000 watts) to power appliances like a sump pump, refrigerator, and other essential appliances simultaneously. In addition to powering a heater, a 5-kilowatt portable generator can be used for other essentials as well.


if you don’t plan on taking your small generator to other locations for purposes other than powering sump pumps, you do not need to have a wheel kit.

The wheel kit would make that process much easier if you were moving it around or loading it onto a truck to move it to a construction site or to use for power tools.

Control Panel

The electric start makes it easy to start the generator quickly. It is different from using a recoil start, which can pose challenges for you before it can start your generator.

The features available on the control panel will help you determine whether you are operating the sump pump generator correctly. When choosing a generator, make sure the display shows different parameters.

Fuel Supply

The size and quantity of appliances a portable generator can accommodate will be determined by the number of outlets found on it. You can power as many appliances as you wish with stand-by models that run directly on your home’s fuel supply.

Your generator will run efficiently using different sources of power when it is dual fuel compatible. You can use it when one of the fuel sources is not available.

Noise Level

The sound from generators can reach 100 decibels or the equivalent of a lawnmower running non-stop. Make sure the generator’s decibel rating meets the requirements if you will be running it in a noise-restricted environment.

If you’d prefer to use a quieter generator, consider an inverter. For reduced noise levels, select generator models run at lower speeds or feature Quiet Test technology.

Best Generator For Sump Pump

Here are some portable generators for sump pumps that can keep your pump pumping during a power outage.

Durostar DS4000S – Portable Generator For Sump Pump

The DuroStar DS4000S 7HP portable generator for sump pumps has everything a homeowner owner needs. The device is intended for light-duty and emergency backup applications. From its all-metal construction to its Surge Arrest, which protects your generator from power surges, this one has it all.

The construction of this sump pump generator makes it tough enough to last even in the toughest places. The DuroStar DS4000S is capable of generating 4000 peak watts which is more than enough for most household sump pumps. You can even run high-amperage power tools using this machine.

On a full tank of gas, you can expect a runtime of eight hours without any interruption. Moreover, it is fitted with a mechanism that will automatically shut off the generator when it detects that the oil levels are low. Additionally, it has a power panel with outlets to meet the needs of every homeowner.

The device includes two household 120V outlets as well as a twist lock 120V 30amp outlet. A voltmeter is also included for measuring the output voltage. This generator is approved by both the CARB and the EPA. Last but not least, the 208cc OHV engine ensures you get plenty of power when you need it the most.


  • 3,300 running watts and 4,000 peak watts.
  • It is powered by a 208cc OHV engine.
  • Emergency low-oil shut-off.
  • Runs quieter than a lawnmower..


  • Nothing to nitpick about.

Champion Power Equipment 100555 Portable Sump Pump Generator

The Champion Power Equipment 100555 is an RV-ready, gasoline-powered portable generator with a peak watt of 4375 and a running watt of 3500. It is powered by a 4-stroke 208cc OHV engine that ensures an interruption-free 12-hours of run time. Even though it’s a powerful generator, it runs very quietly.

At 50% load, the sound only reaches 68 dBA. This is a very convenient 3500-watt generator that is perfect for keeping your sump pump running during long power outages. Let’s talk about the safety aspects of this generator. It comes with a built-in surge protector called the Volt Guard.

The feature keeps your equipment and appliances safe by preventing overloads. It also features a low oil shut-off sensor, push-to-reset circuit breakers, and an oil funnel for easy oil changes. As for the control panels, there are two 120V AC outlets, one 30A 120V outlet, and a 120V 30A locking outlet.

The generator is also capable of providing you with ample backup power during periods of outage. Additionally, cold weather start is guaranteed thanks to the Cold Start Technology. With this generator, you can even start and run a 15,000 BTU air conditioner to cool your RV during an outage.


  • It runs on a reliable 208cc single cylinder.
  • A low oil shut-off sensor built-in.
  • Champion’s reliable recoil start for easy startup.
  • Low noise level of 68 dBA.


  • It doesn’t come with wheels.

Rainier R12000DF – Natural Gas Generator For Sump Pump

Last but not least, we have a powerful, heavy-duty dual fuel generator from Rainier Outdoor Power Equipment. The Rainier R12000DF is a hybrid generator that runs on a heavy-duty 4 Stroke 457cc OHV Rainier engine. It has a 6.6-gallon capacity fuel tank and also includes a fuel gauge.

For safety, there is an automatic low oil shutdown that turns of the generator when it senses a low oil level. Now, the key feature of this generator is its dual-fuel compatibility. If you run out of gasoline, you can simply connect a propane gas tank and keep the generator running.

On propane, this generator can produce 10800 starting watts and 8500 running watts. This means you can connect multiple household appliances at once during power outages. Also, it is the most powerful portable generator for sump pumps on this list. On gasoline, the number goes even higher.

It can reach a peak watt of 12000 and a running watt of 9500 on gasoline. A full tank of gas can keep the generator running for 17 hours at a time if you use 25% load. This portable generator includes a wheel kit for easy transportability. There are two foam grip handle and 10-inch tires included in the kit.


  • It runs on a heavy-duty 457cc engine.
  • You can connect it straight to your manual transfer switch.
  • Two fueling options for convenience.
  • Push to start electric start switch.


  • Excessive propane usage.

Sump Pump Battery Backup Vs. Generator

Generators can keep your system running for an extended period during a power outage. If you’re only worried about this at home, then that’s fine.


A portable generator and an extension cord from the basement window to the generator could be installed or, if you don’t want to get a portable generator, you could get one installed.

Alternatively, you could install an automatic transfer switch and start capability on a whole-house generator if you prefer not to worry about starting the generator manually.


A battery system can back up an existing sump pump, but it’ll have to be a fairly powerful one depending on the size of the sump pump. Sump pumps draw a lot of power, so you will need a large battery bank if you intend to run them all day.

Use Cases

To run it with an external battery pack, you’ll probably need a 1500-2000 kVA unit.

At that point, rackmount systems are your only choice, not standalone units. Backup systems using 12V batteries, like those you see, use a smaller pump, but they are available to buy separately. A couple of deep cycle batteries can be ganged together for longer runtime.

It is possible to invest in a small generator if you find yourself in that kind of situation, even if your generator isn’t hard-wired into your house. However, you should prepare a plan to power the sump pump, refrigerator, etc., with a few hundred dollars’ worth of equipment and some extension cords.

Alternatively, if you don’t have a flood-prone basement and your backup requirements are moderate, you can go for a backup sump pump with a battery. Keep the batteries in check (and likely replace them) every few years. Pumps themselves last much longer than these accessories.


In the event of a storm or power outage, I believe this should give your basement the best protection.

It’s not enough to have one sump pump – you need two. Install a top-notch battery backup sump pump. Make sure it comes with monitoring sensors and water alarms.

You should have enough backup power in case of power outages for a couple of days. In the event of prolonged outages, you may want to consider a generator to power those items and other items in your home.

How To Install A Generator For A Sump Pump?

There is not much to it when it comes to installing a portable generator. However, there are a couple of things that you should follow to install a generator for a sump pump.

Pick The Right Generator

To make sure that your sump pump runs no matter what the situation, you should start by choosing a powerful generator. Generators that are utilized at less than 75% of their capacity are highly efficient. Do your maths, calculate the wattage, and pick a generator accordingly.

Check The Generator Before Installing

Check your generator regularly to ensure it’s in good running condition. Check the generator for defects, and make sure it is clean.

Make sure your generator is clean, as a dirty generator can cause larger problems later on. Make sure it fires up by giving it a few test pulls. You don’t want to install a generator that doesn’t fire up.

Keeping A Good Distance

When you are setting up your generator, keep at least 15 feet of distance from the machine to the door or window. Most portable generators run on a combustion engine that emits fumes. If not properly ventilated, the generator is likely to produce fumes that are harmful to humans and pets.

Keep a minimum distance of 15 feet away from windows or doors if you’re able to put the generator outside. By maintaining this distance, hazardous gases will have time to dissipate before it gets into your home.

Depending on the size of the generator, this can also reduce noise levels because they tend to be very loud. What happens when you have to use a generator in an enclosed space without ventilation holes? A generator exhaust can be made to route the gases outside.

Generators can be used in garages or under awnings when it is wet or snowing with these exhausts. Generators can be used in wet weather by plugging them into these structures — they are easy to make and can be used in a variety of ways.

Get the Correct Extension Cord

Extension cords are very important. If you don’t know what type of cord to use, check the user manual of your generator. Also, you can check online to find the best-suited extension cable for your generator.

Avoid using a cheap extension cord to lead to overheating and shocks and damage your appliances and generator. You should use construction-grade extension cords when you use generators with extension cords.

Calculate the extension cord size by measuring or eyeballing the distance between the sump pump and your machine. The only way your sump pump will use power from your generator is through this. Do not take it lightly.

Load Up The Tank

Fill your generator with fuel before connecting your sump pump and turning on the generator. I know this is a very common thing to forget, but it happens a lot. When people are in a hurry to save their basement, they can easily forget to put gas in the generator.

Connect The Generator To Your Sump Pump

Last but not least, make sure your generator is powered by the sump pump and make sure everything is functioning properly.

You should hear the sump pump turn on and notice the water level decrease as the power reaches the sump pump. Check that the sump pump is moving water where it is supposed to and the flow of water.

Frequently Asked Questions

What size generator do I need to run a sump pump?

The power of a generator is measured in kilowatts.
1000 watts = 1 kilowatt
Key appliances in the average home consume between 5,000 and 7,000 watts.

If you wish to run multiple appliances simultaneously, add the total wattage of those appliances together to determine the size of the generator you need.

Also, you should take into account surge wattage requirements for motor-driven appliances. It is recommended that you run your generator at 75 percent capacity to maximize efficiency.

You can determine the generator size you need for your sump pump after determining the amount of power you require. You should be able to get by with a medium-sized generator in most cases.

How many watts do I need to run a sump pump?

The power consumption of sump pumps is generally high when they are started. Before they can stabilize and run continuously at 500 watts, the surge of power can reach as high as 2000 watts. For your safety, you should buy a generator that has a surge capacity of more than 2000 watts.

Also, will a generator that delivers 2000 watts run a 1/3HP sump pump? If you are using an electric range connected to a generator, you will have to use the entire 2000 watts of power. When a storm hits, the sump pump can be started up and keep on running on a 2000-watt generator.

How to hook up a generator to a sump pump?

First, get yourself a portable generator. Along with that, you will need a long extension that can keep your generator at a safe distance from your home. Ensure that the cord can reach your pump. Fill up your generator with fuel. Start the generator by plugging in the extension cord.

Be sure to turn your sump pump on once you’ve connected it to the extension cord and make sure it is running. Be sure to monitor the water level to ensure it is functioning properly. Generators should never be near or in enclosed spaces such as a garage, tent, or home.

Final Words

And that’s all there is to it. These are the best generators for sump pumps that should provide you with plenty of starting power to start the pump. Also, the running watts on these machines are more than enough to power multiple household items continuously at once.

If you are one fence about which one to choose, I would suggest you go with the Durostar DS4000S. It is powerful enough to keep your sump pump going for long hours. On the other hand, If you need more power, go with the Rainier R12000DF. This one can be powered using gasoline and propane.

About the Author Juan Williams

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