Why your well pressure drops and what you can do about it
Low water pressure from a well usually comes from one of three places: the pressure tank has lost its air charge, the pump itself is failing, or sediment is clogging the system. You can check and fix the first two yourself. The third often needs a professional. Before you call anyone, test your pressure gauge and listen to how the pump sounds—that tells you which direction to go.
The good news is that well pressure problems are usually fixable without replacing the whole system. The bad news is that some fixes cost money and a few require a licensed well contractor. This guide walks you through what you can test yourself and when to bring in help.
Key Takeaways
- A pressure tank that has lost its air charge is the most common cause of low well pressure and can often be refilled yourself with a bicycle pump or air compressor.
- If your pump cycles on and off constantly or runs without stopping, the pressure switch or check valve is likely the problem and usually requires a professional repair.
- Sediment buildup in the well, pipes, or pressure tank reduces flow and may need the well to be flushed or the tank drained and cleaned.
- A failing pump motor shows itself through weak pressure that does not improve, strange noises, or pressure that drops suddenly after working fine for years.
- You can measure your current pressure with a straightforward gauge that screws onto any outdoor faucet, which costs under $15.
Check your pressure tank's air charge first
The pressure tank stores water under air pressure so your pump does not run every time you turn on a faucet. Over time, the air charge inside the tank leaks out or gets absorbed into the water. When the air is gone, the tank fills with water but cannot push it out with force, and your pressure drops.
To check the air charge, turn off the pump at the breaker and drain the tank completely by opening the lowest faucet in your house and letting it run until nothing comes out. Then feel the top of the tank with your hand. A tank with a good air charge feels firm and hollow when you tap it. A tank that has lost its charge feels heavy and sounds full of water when you tap it.
If the tank sounds waterlogged, use a bicycle pump or air compressor to add air back in. The tank has a valve on top that looks like a car tire valve. Attach your pump and add air until you hear a slight hiss—you are aiming for about 2 pounds per square inch (psi) less than your pump's cut-in pressure. If you do not know your cut-in pressure, start with 30 psi and adjust after you turn the pump back on and test the pressure at a faucet.
Turn the pump back on and wait a few minutes for the tank to fill. If your pressure comes back, you have solved the problem. If it does not, move to the next section.
Test your pressure gauge and pump cycle
Screw a pressure gauge onto an outdoor faucet or a test port near your pressure tank. Turn on the pump and watch the gauge as the tank fills. Write down the pressure when the pump turns on (cut-in) and when it turns off (cut-out). A typical well system cuts in at 30 psi and cuts out at 50 psi.
If the pump never turns off, or if it turns on and off every few seconds, the problem is not low pressure—it is a stuck check valve or a failed pressure switch. A check valve is a one-way gate that keeps water from flowing backward into the well. When it sticks, water leaks back down the well line, and the pump runs constantly trying to refill the tank. A failed pressure switch does not signal the pump to stop. Both of these require a licensed well contractor to repair.
If the pump cycles normally but your pressure is below 30 psi, or if it was normal yesterday and dropped suddenly today, sediment or a failing pump is the likely cause. Listen to the pump while it runs. A healthy pump hums steadily. A pump that is failing often makes a grinding noise, squeals, or sounds like it is laboring.
Flush sediment from your well and pipes
Sediment—sand, silt, and mineral particles from the well—clogs the pump intake, the pressure tank, and the pipes in your house. It reduces pressure and can damage the pump over time. If your pressure dropped gradually over weeks or months, sediment is likely the cause.
Start by draining and flushing your pressure tank. Turn off the pump, open the lowest faucet in the house, and let the tank empty completely. Then attach a garden hose to the drain valve at the bottom of the tank and open it to flush out any sediment that has settled. Let the water run until it runs clear, which may take several minutes.
Next, flush the well itself. Turn the pump back on and open the lowest outdoor faucet in your house. Let it run for 15 to 20 minutes at full flow. You may see brown or cloudy water at first—that is sediment being pushed out. Keep running it until the water runs clear. This clears sediment from the well intake and the main line.
If sediment keeps coming back, the well screen may be damaged or the well may be running dry during peak use. A well contractor can pull the pump and inspect the screen, or test the well's recovery rate to see if it is keeping up with your household demand.
When the pump itself is failing
A submersible pump (the most common type in residential wells) typically lasts 15 to 25 years. When it starts to fail, pressure drops even after you have checked the tank and flushed the lines. You may also notice the pressure is weak right after the pump turns on and gets weaker as you use water, instead of staying steady.
A failing pump often makes noise—grinding, squealing, or a rattling sound—because internal bearings are wearing out. Some pumps fail suddenly and stop producing pressure altogether. Others fail slowly, losing a few psi per month until one day you have barely a trickle.
If your pump is old and pressure has dropped gradually, or if the pump is making noise, you need a licensed well contractor to pull the pump and test it. Replacing a submersible pump is not a homeowner job—it requires special equipment to pull the pump from the well and reinstall it safely. The cost varies widely depending on how deep your well is and what size pump you need, but budget for a service call to diagnose the problem before you commit to a replacement.
Upgrade your pump or tank if they are undersized
If you have added bathrooms, a washing machine, or other water-using appliances since your well was installed, your pump and tank may not be large enough to keep up with demand. When demand exceeds what the pump can deliver, pressure drops during peak use—for example, when someone showers while the washing machine runs.
A well contractor can test your pump's flow rate (measured in gallons per minute) and compare it to your household demand. If the pump is undersized, you have two options: install a larger pump, or add a second pressure tank to store more water between pump cycles. Adding a tank is usually cheaper than replacing the pump, but it takes up more space.
Before you upgrade, make sure the well itself can produce enough water. A well that is running dry during peak use will not produce more water no matter how big the pump is. Your contractor can perform a recovery test to measure how fast the well refills after heavy use.
Frequently Asked Questions
Can I replace the pressure tank myself?
You can drain and disconnect an old tank, but installing a new one requires connecting it to the pump discharge line, the house line, and the pressure gauge—and getting the air charge right. Most homeowners hire a plumber or well contractor for this. If you are handy with plumbing, it is doable, but mistakes can damage the pump or create leaks.
What pressure should my well system have?
Most residential wells are set to cut in at 30 psi and cut out at 50 psi. Some systems run at 40/60 or 50/70 depending on the house size and water demand. Your pressure switch is set at installation and should not need adjustment unless you are adding significant water use to the house.
Why does my pressure drop when I run multiple faucets?
If pressure drops only when you use a lot of water at once, your pump or well may not be large enough for your household demand. If pressure drops even with light use, the problem is the pump, tank, or sediment as described above. A well contractor can test your pump's flow rate to tell you which it is.
How often should I have my well serviced?
Most well systems need a professional inspection every three to five years. A contractor can check the pump, pressure switch, and tank, and catch problems before they leave you without water. If you notice pressure changes, strange noises, or discolored water, call sooner.
Is low well pressure a safety issue?
Low pressure is not dangerous, but it is inconvenient and can indicate a problem that will get worse. If sediment is clogging your system, it is also wearing out the pump. If the pump is failing, you may lose water entirely. Address pressure drops within a few weeks rather than waiting months.