Can I Run My Well Pump With A Generator? (Yes!)

Many people rely on their own water supply systems in their homes. Usually, they have their Well pump. That is why continuous electricity supply is crucial to them. Sad but true, we face electricity failure during tropical storms and other disasters. So, people like me want to buy and install a generator for emergencies. 

Everybody knows the generator is good for small appliances. But when it is a large appliance like a well-pump, people become confused. Actually, you can run your Well pump smoothly with a portable generator these days.  

In this article, I will discuss elaborately the size selection of the generator for your Well pump. So, stay tuned!

Can I Run My Well Pump With A Generator

Can I Run My Well-Pump with a Generator? 

Yes, you could run your well pump with a generator. Even you could run your well-pump with a portable generator by plugging directly. The process depends on the power of your pump and the generator. 

The running watt of a 1/3 Hp Well-pump is 750-watt. And the starting watt of this particular Well pump is 1500 watts. That means, with a 2000-watt portable generator, you can smoothly run your Well pump. Anyway, keep reading to learn more about the perfect sizing of the generator for a well-pump.

An Estimated data of the conventional well-pump with their starting and running watt. This is only for generating ideas. Please, read the manual book to get a precise idea.

Well Pump SizeRunning Watt (typical)Starting Watt (typical)
1/3 HP Well-Pump750-watt1500-watt
1/2 HP Well-Pump900-watt2000-watt
3/4 HP Well-Pump1500-watt3000-watt
1 HP Well-Pump2000-watt4000-watt
1.5 HP Well-Pump2500-watt5000-Watt
2 HP Well-Pump3750-Watt 7500-Watt
3 HP Well-Pump5000-Watt10000-Watt
The Wattage varies with the brand and product. This is an estimated Chart Only.


What Size Generator Do Well Pumps Need?

Believe me, this is the most common question I have ever heard regarding well-pump during the blackout. There is no assumption here. Actually, no one can not tell you the exact or perfect generator size without knowing the power of your well-pump. 

You know, every electronic appliance has a starting and running wattage. Starting wattage is more than the running wattage. 

Say, you have a well-pump of .5 HP. You know, 1HP=746 watts. That means your well-pump comes with 373 watts. This is the running watt actually. You need a generator that comes with at least 10% more wattage supply than the starting watt. 

I would always recommend going for at least a 2000-watt generator for the Well pump. You can use lower than the 2000 watt. There is no doubt here. 

But, a high output will give a lot of flexibility. During a blackout or disaster, you not only need to run your Well pump but also other small appliances. 

In these circumstances, a large generator helps you to run the other household appliances along with the Well pump. 

generator for well pump

Can A Portable Generator Run A Submersible Well Pump?

Yes, you could use a portable generator to run the submersible well pump. People usually think it is not possible to run a submersible pump with a portable generator. But it is nothing but a misconception

You just need higher output than the starting watt of your submersible well pump. The calculation is very simple here. don’t make it complex anymore. 

How Many Watts Does Submersible Well Pump Use?

Say you have 1 HP submersible pump. That means your submersible will draw 746 watts in a 120 volts line while running. Since you need more than 746 watts to start your submersible, a 1500-watt generator is the best fit in this case. 

Yes, you could run your submersible with less than 1500 watts but it would not be a good idea for long-term use. 

Sump Pump SizeRunning Watt (typical)Starting Watt (typical)
1/3 HP Sump Pump800-Watt1300-Watt
1/2 HP Sump Pump1050-Watt2100-Watt
The Wattage varies with the brand and product. This is an estimated Chart Only.

Can I Plug My Well-Pump into a Generator?

Yes, you could directly plug your well pump into a generator. You need a portable generator for direct use. For other types of generators, you need a wiring line. 

Portable generators are effective indeed. they are a worthy investment. Apart from the large appliance like a washing machine or AC, you could run all the small appliances with a small but powerful portable generator. 

Even you could run the AC and washing machine if you have a larger portable generator than the sum of the other home appliances. 


Will a 2000 Watt Generator Run a Well Pump?

A 2000-watt generator can run up to a 3/4HP well pump smoothly. A 3/4HP well pump means that it needs a 560-watt power supply. So, a 2KW generator could easily run it. 

Will a 3500 Watt Generator Run a Well Pump?

Yes, you can run a 1/3 HP, 1/4 HP, 1/4 Hp Well Pump with a 3500 Watt generator smoothly. But you can not run 1 HP or more than 1 HP Well pump with a 3500 Watt generator. because a 1 HP Well Pump needs 4000-watt starting power and 2000 running power. So, the 3500-watt generator is not enough to provide the power to start the Well pump.

Will a 4000 Watt Generator Run a Well Pump?

Yes, a 4000-watt generator can run a Well pump up to 1HP easily. With a 4000-watt generator, you could run almost all of your home appliances at a time except for the large appliances. If you want to run a small device like a laptop, or computer, you could go for the portable generator. The portable generator is comparatively quieter than the regular generator. 

Will a 5000 Watt Generator Run a Well Pump?

Yes, you can run the smallest to medium-powered Well Pump with a 5000 Watt generator. A 5000 Watt generator is perfect for running Up to a 1.5 HP Well Pump. If you run the smaller well pump below 1 HP, you can run other home appliances like the refrigerator and freezer simultaneously.

Will a 5500 Watt Generator Run a Well Pump?

You can run the 1.5 HP Well Pump smoothly with a 5500-watt well pump. Like the 5000-watt generator, you can run other home appliances along with a Well Pump during a prolonged power outage or in the off-grid cabin.

Final Notes 

Actually, it can not be answered in a figure that what size generator will you need to run a Well pump. You must know the power of your Well pump to figure out the value. It would be great if you know the starting watt and ruining watt of your Well pump. 

Then you could easily figure out the actual value. A portable generator is enough if it provides more than the starting watt than your Well pump. 


Rayan is an engineer, lives in a farmhouse. He has a passion for electronics and alternative energy. He loves to share his thoughts with other people. That is why he started the blog.

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