How to Troubleshoot Low Water Pressure On Well Water Systems
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Episode 15. How to Troubleshoot Low Water Pressure On Well Water Systems
Read or Listen to See How to Troubleshoot Low Water Pressure On Well Water.
Today’s episode is about troubleshooting low water pressure on well water for homes and small businesses.
Do you have plenty of water but experience low water pressure? This is a common problem.
I put together a Checklist and quick Troubleshooting guide called “How to Troubleshoot Low Water Pressure On Well Water.” This free guide includes pictures, checklists, and things to look for to troubleshoot low water pressure (see the link below to get your guide).
Discussed during this episode:
1. What is the water pressure, and what is the difference between water pressure and flow rate?
2. Determine your water pressure and the flow rate before any water treatment systems or plumbing.
3. How to Troubleshoot common problems with low water pressure and flow rate.
4. How to read a filter pressure drop chart and a pump curve chart.
5. How to size whole house filters, automatic backwash filters, and softeners to avoid pressure drop problems.
6. What is the water pressure, and what is the difference between water pressure and flow rate? “> Click here to subscribe” data-mce-href=” Click here to subscribe“>
What is Water Pressure?
Water pressure refers to how strongly water flows through your pipes, measured in pounds per square inch (PSI). In well systems, pressure is typically maintained by a submersible pump and a pressure tank with an air bladder.
Most homes run best with 50–60 PSI. Too low, and you’ll get weak flow—especially in multi-bathroom homes. Too high (above 70 PSI), and you risk damaging appliances.
You can check your system's PSI using the pressure gauge near your pressure tank. Standard systems cycle between a lower and upper range (e.g., 30–50 PSI), while constant pressure systems aim to hold steady at one setting.
Knowing your PSI helps you troubleshoot low water flow and keep your system running smoothly.
What is Flow Rate?
Flow rate can be thought of as gallons per minute flowing through a pipe. A common residential well pump might deliver anywhere from 5 to 20 gallons in one minute. Pressure is not the same as flow, however.
For example, you could have great water pressure from the well but a terrible flow rate and reduced water pressure in the home.
Most pipes in traditional homes are ½”, ¾,” or 1” in diameter. Say you had really great water pressure of 60 or 70 PSI, and your home had all ½” piping, and you had 3 bathrooms all being used at the same time, or you had a large spa-type bathtub that likes to be filled at 15 gallons per minute.
Because you have ½” piping, you might experience a low flow rate, even if you have 70 PSI to start with, because the flow rate needed requires a larger diameter pipe.
How to Find Out You're Well Pumps Flow Rate
If you get a chance, listen to Episode 2, where I discuss how easy it is to find out your well pumping flow rate and what it is. I am putting a link in the show notes that goes to a page that shows how to check your well flow rate easily. Basically, the flow rate in gallons per minute is how many gallons can flow in one minute.
Link to Flow Rate Calculator Page
Pumps are typically set to turn on automatically at one pressure and off at a higher pressure, usually 20 PSI higher than the low pressure.
Standard single-speed submersible wells or booster pumps operate with a pressure range that fluctuates between a low and high setting. Some homeowners use a constant-pressure system, which maintains steady water pressure throughout the home.
Standard systems use a pressure switch to turn on and off the well pump. If you measure the drawdown from your pressure tank in gallons and determine how fast the well pump refills it, you can easily know the flow rate in gallons per minute.
(Click here to learn more about troubleshooting well water systems.)
Here are the steps:
- Measure the number of gallons drawn down from the pressure tank until the well pump turns on.
- When you hear the pump turn on, immediately close the hose bib.
- Time the period in seconds it takes for the well pump to build back up to pressure, that is, between the cut-in and cut-out of the pressure switch. The pressure switch turns on the pump at a lower pressure and turns off the pump when it reaches a higher pressure.
- The simple formula for determining the flow rate is gallons drawn down (that were measured above), divided by the seconds required for recovery, then multiplied by 60: (Gallons / Seconds) x 60 = Gallons per Minute (GPM) flow rate.
- For example, if 20 gallons are drawn down, it takes 120 seconds to build pressure back up. Then, 20 divided by 120 = .166. Then multiply .166 x 60 = 10 gallons per minute flow rate.
So, in this example, you have a 10 GPM flow rate.
Checklist: How to Troubleshoot Low Well Water Pressure
- Weak Pump Flow
A worn-out pump, clogged screen, stuck check valve, or broken/corroded pipe can lower pressure. Sudden drops may signal pump blockage. Contact a well pro—visit wellowner.org to find one. - Low or Faulty Pressure Switch
You can adjust the pressure switch, but be cautious—it affects tank drawdown and may not work if your pump can't handle higher pressure. Switches may also need cleaning (watch for ants!)—best left to a pro. - Bad Pressure Tank
The air bladder inside may lose pressure. Turn off the pump, drain water, and check air pressure. Faulty switches are also a common culprit. - Clogged Pipes
Rust, scale, or sediment buildup can restrict flow. A plumber can inspect and diagnose the issue. - Stuck or Faulty Valves
Gate or ball valves can stick if unused. Replace or clean them to restore pressure. - Failing Pressure Regulator
If installed on your main line, a pressure regulator may become clogged or fail over time. Replacement may be needed. - Clogged Fixtures
Low pressure at a single faucet? Clean or replace aerators and showerheads blocked by mineral buildup. - Filter Issues
Dirty cartridges, softeners, or iron filters can restrict flow. Check filters regularly and compare pressure before/after them.
How to Select and Size Automatic Backwash Filters and Water Softeners to Avoid Pressure Problems
The first step is to check with and follow the water treatment manufacturer's recommendations. They will often tell you the maximum flow rate in gallons per minute.
Another point is to avoid using a filter or softener that will reduce the pipe's size. So, if you have a large home or need to fill a swimming pool or commercial application, you generally don’t want to put a filter with a ¾” pipe size on plumbing that uses 1” or, say, 1-¼” piping.
You want to use a system that can filter and treat your water without restricting your flow rate and reducing water pressure.
The chart above shows the service flow rate of various filter media and water softener resins. One common way to size filters and softeners is based on the square footage of the tank's top surface area. For example, a filter tank that is 14″ in diameter has a top filter media surface area of 1.07 square feet.
If you select a filter media that can work well at 5 gallons per minute per square foot and have a 1 square foot filter, you could filter well at 5 GPM.
The chart above shows the “service flow rate” for various media, which is the flow rate if you filter for hours at a time. However, for homes, most of the filter media below can filter at 2 – 3 times the service flow rate for a short time (the Peak Flow Rate or Maximum Flow Rate) and still perform well.
