Best Generator for Sump Pump [Guide And Reviews]

A generator for sump pump is an essential alternative during power outages. This is important for buildings with basements where water needs to be pumped out to avoid flooding. If you don’t have an alternative way to power up the sump pump, you will end up with a flooded basement and damages costing hundreds of dollars. Although this may seem easy to buy a small generator for sump pump, considering the size and power output of the generator is very important. Let’s identify the process of determining the size of the generator for a sump pump and how to choose the best among the many options available in the market.

What Size Generator Do I Need To Run A Sump Pump?

There are some factors to consider when choosing the correct size for a sump pump. This includes the power rating, generator usage, and the number of sump pumps that need to be powered up by the generator. Having a proper idea of these important features is important when looking for a backup generator for sump pump. Let’s identify what you need to focus on related to these factors.

The Power Rating

You need to read the electrical rating on the sump pump which will be indicated at the back. You can find information such as the voltage, frequency, amperage, and horsepower. You can estimate the power required for the sump pump using this information.

Continuous Power Supply Required=Voltage×Amperage

However, like most other electrical appliances, sump pumps also need starting wattage in addition to continuous running power. The starting wattage is relatively higher than the running wattage. So you need to go for a generator that provides power higher than the running wattage of the sump pump.

Usage of the Generator

Next, you need to think about the additional uses of the generator. Sometimes you may need to light up a few bulbs or run a fan and some small devices with the same generator. If so, you need to add the power requirement of these appliances to the power consumed by the pump sump and decide on the final power rating. If you are concerned about the amperage of the system, knowing more about what size portable generator to power 200 amp service will also be useful.

Number of Sump Pumps

If you have multiple sump pumps, then add up all the power ratings of them to find the power requirement. Different makes and models may have different power ratings. So check them carefully when adding up the values. Some generators facilitate connecting them parallelly using connector kits to get more power output. You need to have two identical generators to double the power using this method.

Determining The Generator Size

After finding out the power requirement of your sump pumps, you can then choose the right size of the generator. When the sump pumps have more horsepower they will draw more power from the generator. For example, a sump with 0.75 horsepower will run at 800 watts but needs 1300 watts to start. Similarly, a 0.5 horsepower sump would need 2150 watts for starting and then run at 1050 watts. Selecting a generator that delivers at least 20% more power than the starting power will be a wise choice. This is because you need to have more power than the exact amount needed by the sump pumps. The generators should not run at full load all the time as it will cause premature wear and tear. 

Considering a sump pump of 1 horsepower which is around 745.7 watts, the running power is preferable to be around 1.5 times or twice this amount. This shows that a generator of around 1500 watts will be a good generator for sump pump. But if you need to power up a few lights, fans, and electrical devices in addition to this, you need to consider getting a larger generator. In addition to this, you also need to determine the size of the gauge wire to be used. You need a 16 gauge power cord of length 50 feet to power up the sump pump and another cord of the same dimensions for the other appliances.

How To Install A Generator For A Sump Pump?

A generator should always be installed outdoors at least 20 feet away from the doors and windows of a building. This is because they emit toxic gases including carbon monoxide which are poisonous when inhaled. Setting up the generator far from your living space will also give you the advantage of less disturbance due to noise during its operation. Therefore, avoid running your generator inside closed spaces such as garages and porches. You can create a separate shed away from your house to protect the generator from rain and snow. Place the generator on a higher surface to avoid flooding of water during wet seasons. For your information, here’s how to run a generator in rain.

The wires and connecting tools are very important in connecting the sump pump to the generator. You can try it if you are experienced in the field. If not, it should be installed by a professional technician or an electrician to prevent any faults. 

Alternatives To Sump Pump Generators

The sump pump generator backup is also important during emergencies where the usual generator may not be able to function. The practical alternative for this is a battery-powered generator for the sump pump. They are suitable for running for a short time since they have a limited running time. Water-powered backup is another sump pump generator backup. This is a good solution for deep flooding where the generators run on the power of water. They can run for many hours even if there is no electricity. This works best when the water is maintained at a specific level and needs constant water flow. So are generators waterproof when running in these conditions?

Features Of Best Sump Pump Generators

The most important thing to know before purchasing a generator is the power rating of the pump. The generator should have appropriate surge power that is enough to start the pump. The generator will not be able to operate the sump pump properly if it does not have enough surge power and running power. In addition to this, the following important factors need to be considered when selecting the best generator for sump pump.


The surge power at the beginning is approximately 20% more than the running power. Therefore, if you get a generator of power 3000 W, the peak power needs to be 4000 watts. When considering the power requirement of a sump pump, it is better to start with a generator of 2000 W. 

Run Time

The run time of the generator needs to last more than the working time of the sump pump. You can find good generators that have very high fuel efficiency and runs for over 12 hours on propane

Noise Level

The noise generated during operation is one of the greatest downsides of a generator. Therefore, it is important to select a generator with a low noise level at least below 60 dB. Many inverter generators have new muffling technology which brings down the noise level to around 50 dB. 

Dual Fuel Mode

Some modern generators run on both gasoline and propane. A generator with this dual fuel mode is more advantageous as you have two options in fueling up to run the sump pumps. The running time of these generators varies depending on the type of fuel. Usually, the generator runs longer on propane than when using gasoline.

Control Panels

Go for a generator with a display panel that shows the functioning parameters and allows you to control its functions easily. There are also multifunctional control panels that make the usage of the generator more convenient.


There are generators for various prices in the market depending on the brands and models. The best generators for sump pump may cost something from $500 to $6,000. Although there may be plenty of high-end generators, you can always choose something affordable to suit your requirement. 

Where to Buy

You can find generators for sump pumps at your local hardware stores. But purchasing them online at Amazon allows you to select from a wide range of products at a cheaper price.

How Best Generators are Picked

The best generators are selected by testing in certain ways. First, the generators are plugged directly into a sump pump to check the function. The amperage of the generator output is also tested. The run time is tested to whether it can run for at least 4 hours before shutting down. The size and weight of the generators are also considered when picking the best generators. 

Customers may occasionally have issues related to the products they bought. Therefore, the quality of the customer service is also considered in selecting the ideal generator brand. Finally, the generator should be affordable both in the initial purchase and maintenance. If the product is too cheap, you need to be careful as the quality could be compromised. Generators are usually built to resist external damages and optimize their function. Learn more about; are generators EMP proof?

Best Generator For A Sump Pump

The following are some of the recommended generators for sump pumps. Depending on your power requirement, you can choose the best generator among them. This also includes the special features and facilities provided by each generator.

1. Durostar DS4000S Portable Generator

This portable generator is very convenient due to its compact size and weighs around 94 pounds. It has an average run time of 12.3 hours with a running wattage of 3300 W and a peak wattage of 4000 W. It consists of a fuel tank that has a capacity of 3.9 gallons. This is considered one of the best generators to power up heavy-duty machinery including sump pumps and refrigerators. This is also an ideal generator for RVs, tailgating, camping, and construction sites. Let’s identify the benefits and downsides of this portable generator.


  • Heavy-duty machine
  • Easy to install
  • Durable construction
  • Has a convenient power panel system


  • Reported oil leaks from the air filter housing
  • No dual fuel option
  • Issues in handles and wheels

2. Champion 3400-Watt Dual Fuel Generator

generator for sump pump

If you are looking for a dual fuel system for your generator, this will be the best choice. It functions with both gasoline and propane. It can run up to 7.5 hours on gasoline and up to 14.5 hours on propane. When low fuel is detected, the auto shut-off system will turn off the system. This can store 0.6 quarts of oil as well. You can easily operate this generator with the touch control panel. It has a surge power of 3400 watts and a continuous running power of 3100 watts. Cold weather is not an issue for this generator as it has cold start technology for an easy start. You can also connect two of these generators using a parallel generator connection to double the output power. There are two 120V 20A household outlets, one 120V 30A RV outlet, and a 12V DC outlet with a USB adapter in this generator.


  • Clean electricity with less than 3% THD
  • Dual fuel system
  • Relatively quiet with only 59dB
  • Quick touch control panel features
  • 3 position start-up switches for an easy electric start
  • Limited warranty of 3 years


  • Sometimes may have carburetor malfunctions
  • Could have functioning issues when running on propane

3. Jackery Solar Generator 1000 Watts

This portable generator is very light in weight at only 22 pounds. It is an ideal solar generator for sump pumps with a powerful solar panel backup. This generator can also be charged with car outlets and wall outlets in addition to the solar power system when traveling outdoors. This is an eco-friendly product with zero emissions. The surge power is 2000 watts and the running wattage is 1000 watts. This is enough to power up a sump pump and keep it running with solar power. It consists of 3 pure sine wave AC outputs, 2 USB C ports, and one charge port. The power tracking allows you to maximize power usage conveniently. A battery-powered generator for sump pump like this will be an ideal solution for your requirement.


  • Can power up to 8 devices
  • Zero-emission 
  • No maintenance cost
  • Versatile, light in weight, and reliable
  • Solar panels can be charged fast within 5 hours


  • Limited to 1000 W
  • May not charge some devices

4. WEN 56203i Super Quiet 2000-Watt Generator 

This is another backup generator for sump pump which is ultralight facilitating convenience in portability. The fuel shutoff system allows maximum fuel management efficiency by detecting low fuel levels. It is also EPA and CARB compliant, implying that this generator is environmentally friendly. It provides clean and reliable power with curbs harmonic distortion limited to 1.2%. This generator weighs 39 pounds with a 79cc 4 stroke OHV engine generating 1700 watts and a surge wattage of 2000 watts. It runs with less noise of only 51 dB at 25% load. The fuel tank provides room for 1 gallon of fuel with a run time of 10.8 hours at the same load. It consists of two 3 prong 120V receptacles, one 12 DC outlet, and two 5V USB ports.


  • Has a light indicator to indicate power output, low oil, and overload
  • The eco mode adjusts the fuel consumption and enhances its useful life
  • Can connect two generators using parallel connection
  • A warranty of 2 years
  • Needs limited maintenance and eco friendly


  • Possible variation of surge wattage
  • May underperform at times
  • Needs external grounding

5. Westinghouse iGen2200 Inverter Generator

This inverter generator is an ideal generator for sump pump due to its quiet operation. It has a noise level of only 52 dB due to low tone mufflers, an insulated acoustic insulator, and asymmetrical cooling fans. The fuel consumption is very efficient as it optimizes the fuel needed to generate power. It can operate up to 12 hours with a load of 25% and provides clean electricity with less than 3% THD. The indicators notify overload and low fuel status. It has a peak wattage of 2200 watts and a running power of 1800 watts.

You can even double the power output by pairing this generator with an ideal one by connecting them parallelly. This weight of 46 pounds can be carried about easily with the built-in handle of this generator. This comes with two 120V 5-20R household outlets and two 5V USB ports. So this will be the best option if you are looking for a backup generator sump pump.


  • Super quiet with only 52 dB
  • Light in weight and easily portable
  • The 1.12-gallon fuel tank supports up to 12 hours of operation
  • Limited warranty of 3 years
  • The speed of 4 stroke OVH engine is automatically adjusted
  • Supports parallel connection to get more output


  • The peak wattage may vary
  • May underperform for large devices
  • The amps and outlets could have matching issues

Frequently Asked Questions

How to use a sump pump generator?

The generator needs to be connected to the sump system so that it is activated automatically during a power outage. Get a professional electrician to connect them if you are not aware. Then the pump would drain the water as required to avoid any flooding.

How many watts does a sump pump use?

To be on the safe side the generator needs to have more capacity than the actual power consumed by the sump pump. Running a small generator for sump pump under maximum load leads to premature damage. Therefore, check the requirements well or get the advice of a professional before deciding on the power rating of the generator. The following table shows the estimated running and starting watts based on the horsepower of the sump pumps.

Pump HorsepowerEstimated Running WattsEstimated Starting Watts
1/3 hp800 W1300 – 2900 W
½ hp1050 W2150 – 4100 W

Can a 2000 watts generator run a sump pump?

A sump pump needs a surge wattage/ peak power of 2000 W to operate a sump pump. So a generator with this rating will power up a sump pump. Selecting the correct size of the generator depending on the requirement is also important. Using an oversized generator means you are paying extra for something that you don’t need. Undersized generators will not be able to run the pump due to inadequate power output.

How much do best generators for sump pump cost?

The best generators cost somewhere from $500 – $6000 depending on the type and power generated. There are also high-end generators for higher prices which are mainly used for industrial purposes. It is also not recommended to go for generators that are too cheap as there might be issues with the quality of the product.

How long will a 12v battery run a sump pump?

You can use a battery-powered sump pump to pump out water during power outages. Most new batteries that are fully charged will last for about 5 – 7 hours of continuous pumping. For non-continuous pumping, this may be around 1 – 3 days depending on the time and frequency of usage.

Should a sump pump in a basement be protected by a GFCI outlet?

A sump pump having a 20 amp septic circuit should have a #12 wire gauge. The sump pump should also be protected by either a GFCI outlet or a GFCI circuit breaker. A method of disconnection for the sump pump must be located closely and readily accessible. In the case of having receptacle outlets, weatherproof covers must be installed even while the sump pump is plugged in.


Having an alternative power source to power up your sump pump is a wise choice as you don’t need costly damages and inconvenience due to flooding. This guide must have helped you in finding the best generator for sump pump depending on your need and budget. These generators will automatically turn on and keep your basements safe from water damage. Go through the user reviews and invest in a quality generator to power up your sump pump.

Similar to this article, you will also find it useful to know what size generator to run the refrigerator and freezer.