How Does a Water Pressure Booster Pump Work?

Meg Scanlon
Written by Meg Scanlon
Updated January 11, 2022
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A water booster pump may solve all of your low water pressure woes

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If you take long showers just to rinse the shampoo out of your hair or your dishwasher takes forever to run, you might have low water pressure. You may have noticed that only a slow trickle of water comes out when you turn on the bathroom faucet or showerhead. These are symptoms of low water pressure, and a water pressure booster pump can help. Before getting one installed by a professional, you first need to rule out other potential causes of low water pressure.   

What Does a Water Pressure Booster Pump Do?

Your water pressure may be low if you get your water from a well or if your city has low water pressure. A water pressure booster pump can increase the pressure and volume of the water coming into your home and improve the flow rate. 

A booster water pump supplies the necessary pressure to move water through the plumbing or from a storage tank. It connects to the main water line right after the main shutoff valve and can typically raise the home's water pressure by as much as 70 pounds.

How Does a Water Pressure Booster Pump Work?

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A booster pump functions much like a fan. Like fan blades spin rapidly to move air, the motor-operated impeller in a booster pump rotates to push water through the pipes faster with the help of a sensing device. 

Some booster pumps take in and push out water in a different manner. Some models have a spinning propeller, and others have an oscillating diaphragm. An oscillating diaphragm pushes water with two rotating plates—one plate has cups on it and the other has indentations. The plates roll together and compress the cups, propelling the water out. When the plates roll open, additional water flows in. 

Test Your Water Pressure

Before purchasing or installing a water pressure pump, measure your current water pressure. If you use the city water system, they can send someone out to measure your water pressure. You can also measure it yourself with a water pressure test gauge with a hose connection. Be sure all faucets and appliances that use water are shut off and not in use.  

The ideal water pressure is 60 pounds per square inch (PSI), and 45 to 50 PSI is on the low end. A reading lower than 40 PSI indicates low water pressure. Water pressure should not exceed 75 to 80 PSI because this could damage the pipes and plumbing system. 

Rule Out All Other Common Plumbing Problems First 

Before you invest in a pressure booster pump, try the following:

  • Ask your local water department to increase the water pressure. 

  • Call a plumber near you to diagnose any underlying causes, such as clogged pipes due to mineral deposits, cracks, or leaks. If low pressure exists in an isolated area only, like one shower, there's probably a clog in the showerhead or connecting pipes. If a clogged drain is the source of a blockage, the cost to unclog a drain is about $250

  • If you've recently moved into a home, the previous owners may have installed pressure limiters to certain fixtures as an energy-saving measure. Check each faucet, and remove any limiters you find. 

  • If you have one, ensure your water softener is working properly. 

Once all other causes are ruled out, a plumber can install a water pressure booster pump. The cost of the average pressure booster is around $800 (not including the labor cost for installing the unit), but the price can increase to over $1,000, depending on the features and size of the booster kit you choose. 

Unless you have the proper training, it’s best to leave this project to the professionals, so you can get back to enjoying your shower without worrying about low water pressure.

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