Answering Your Water Pump Questions
with RPS Engineer Mike
What size water pump for a 2 story house?
This is a great question! You’ll need a bit more pressure from whatever water system you have to reach the upper floor faucets and bathrooms. Properly setting the PSI of your pressure tank is key here, you’ll want at least a 50 PSI or 60 PSI setting to ensure that the water pressure on the second floor is the same as the first floor. Once a water pump pushes water into a pressure tank, the well pumps job is over and the pressure tank is responsible for delivering pressurized water to faucets within the home.
You’ll need to size a water pump that can handle pumping into a pressure tank set to at least 50-60PSI. Sizing a water pump for any home primarily depends on the depth of your well and how much water you need to pump during high demand (plus a couple more factors). Read up on our blog about sizing a water pump here.
Sizing Well Pump by Water Usage
Lets talk about sizing a submersible well pump based on how much water you need to pump during high demand. Our engineers always recommend that if possible, size a pump for the “worst case scenario”, in other words if two people are taking a shower, some is running the washing machine and a faucet is turned on all at the same time, how much water would the require? The more people and appliances you have in the home, the higher the worst case flow that you should expect to calculate for.
Here’s an example of some estimates of flow rates in gallons per minute of appliances…
Washing machine 3-5 GPM
Dishwasher 2-4 GPM
Kitchen Faucet 2-3 GPM
Shower 1-3 GPM
Toilet 2-3 GPM
Single Lawn Sprinkler Head 3-5 GPM
Using the previous example as a model calculation with the upper range…
Shower #1 3 GPM + Shower #2 3 GPM + Washing Machine 5 GPM + Faucet 3 GPM
= 14 GPM total
As long as your well has a production rate of at least 14GPM, you should choose a water pump that can pump 14GPM. If your well has low production, our engineers recommend purchasing a larger pressure tank, at least 100 gallons, to provide a buffer between the pump production and the home consumption.
Take the Next Step to Water Independence
Learn More About Water Pumps
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If you’re considering replacing a well pump and it’s your first time, you may have questions about long it may take. We often say a full install only has to be a couple of hours, but is that actually accurate?Read now
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How many GPM is a good well pump?
Water needs can differ significantly depending on circumstances, and you may need a submersible well pump with a significantly higher or lower flow rate, depending on household size, irrigation needs, and sprinkler use.Read now -
Can you put in too big of a pressure tank?
When it comes to sizing a well pressure tank, there really isn’t an upper limit as to how big of a tank you can put in. There are some pros and cons to different size pressure tanks, and they can have an impact on the lifespan of your pump.Read now