The check valve is usually bolted to the pump discharge port, the outlet where water leaves the pump
On most residential well pumps, the check valve sits directly on top of or when ready below the pump itself, attached to the discharge port. This is the opening where pressurized water exits the pump on its way to your pressure tank and house. You'll recognize it as a cylindrical or square metal body, typically 1 to 2 inches in diameter, with a pipe connection on the bottom (toward the pump) and another on top (toward the tank or well line).
The exact location depends on your pump type. On a submersible pump (the kind that sits inside the well), the check valve is mounted at the top of the pump column, where the discharge line emerges from the well casing. On a jet pump or centrifugal pump (surface-mounted models), it's bolted directly to the pump housing, usually on the side or top where the outlet pipe connects.
If you're looking at your pump and can't when ready spot it, trace the main pipe leaving the pump. The check valve will be the first significant fitting you encounter—before the pressure tank, before any other valves, and before the water reaches your house.
Key Takeaways
- The check valve attaches to the pump's discharge port, the opening where water exits the pump under pressure.
- On submersible pumps, it sits at the top of the well column where the discharge line emerges; on surface pumps, it bolts directly to the pump housing.
- It's a cylindrical or square metal body, typically 1 to 2 inches wide, with two pipe connections.
- You can locate it by following the main discharge pipe from the pump—it's the first major fitting you'll see.
Why the check valve location matters for maintenance
Knowing where your check valve sits is important because it's one of the few pump components you may need to service or replace without calling a professional. A failing check valve causes water to drain backward into the well when the pump shuts off, which makes the pump work harder on the next cycle and can eventually damage the pump motor.
The check valve is also the most common reason a well pump won't build pressure or cycles on and off too frequently. If you notice your pressure gauge climbing slowly or the pump running constantly, the check valve is usually the first thing to inspect. You don't need to replace it yourself—a licensed well contractor should handle that—but knowing where it is lets you describe the problem accurately when you call for service.
Submersible pump check valves: the well column setup
On a submersible pump, the check valve is mounted at the top of the well, where the discharge line exits the well casing. You'll see it bolted to the top of the pump column, which is the rigid pipe that runs down into the well and connects to the pump motor at the bottom.
This location can make the check valve harder to spot if your well head is enclosed in a concrete pad or buried under a sanitary seal. If you have a submersible pump and can't see the check valve from ground level, it may be inside a well cap or protective housing. Lift or remove the cap carefully—don't force it—and look for the metal fitting where the discharge line begins. If you're uncomfortable opening the well cap, a well contractor can show you where it is during a service visit.
Surface pump check valves: easier to access
If your pump sits above ground (a jet pump or centrifugal pump mounted in a basement, garage, or pump house), the check valve is much easier to locate. It will be bolted directly to the pump body, usually on the discharge side. Look for a metal cylinder or square block with two threaded connections—one screwed into the pump, one connected to the pipe that runs to your pressure tank.
Surface-mounted check valves are often easier to replace because you don't need to pull the pump from a well. A plumber or well contractor can usually swap it out in an hour or less. If your pump is in a basement or garage, you can also inspect it yourself for obvious signs of leaking or corrosion, though you should have a professional handle any repairs.
What a check valve looks like up close
A well pump check valve has a distinctive appearance once you know what to look for. It's a solid metal body—usually brass, cast iron, or stainless steel—roughly cylindrical or cube-shaped, and typically 1 to 2 inches in diameter. The top and bottom both have threaded ports where pipes screw in.
Some check valves have a small vent hole or a spring-loaded cap on top; others are completely sealed. You may see a small amount of corrosion or mineral buildup on the outside, especially if your well water is hard or acidic. This is normal and doesn't necessarily mean the valve is failing, but heavy rust or white mineral crusting can indicate the valve is old and may need replacement soon.
The check valve itself has no moving parts you can see from the outside. Inside, there's a spring-loaded flapper or ball that allows water to flow up toward the tank but snaps shut when pressure drops, preventing backflow into the well. You can't service this internal mechanism yourself—replacement is the only option when a check valve fails.
Common signs your check valve needs attention
If your check valve is failing, you'll usually notice one or more of these symptoms: the pump runs constantly or cycles on and off every few minutes even when you're not using water; the pressure gauge climbs very slowly or won't reach normal pressure; water drains from the pressure tank back into the well when the pump shuts off (you may hear a gurgling sound in the well); or the pump motor sounds strained or makes unusual noises.
None of these symptoms automatically mean the check valve is the problem—they can also signal issues with the pressure switch, the pressure tank, or the pump itself. But the check valve is the most common culprit, and it's the first thing a well contractor will inspect. If you notice any of these signs, contact a licensed well service company. They can test the check valve and replace it if needed.
When to call a professional for check valve work
You should not attempt to remove or replace a check valve yourself unless you have experience working with pressurized well systems. The discharge line is under pressure even when the pump is off, and opening it without properly depressurizing the system can cause injury or water damage.
A licensed well contractor has the tools to safely isolate the check valve, depressurize the line, and swap in a new one. They can also test whether the check valve is actually the problem before replacing it, which saves you money if the real issue is elsewhere. Call a well service company if you suspect check valve failure, or if you straightforward want to know the condition of your check valve during a routine maintenance visit.
Frequently Asked Questions
Can I see if my check valve is leaking without taking it apart?
You can look for obvious signs: water pooling around the valve, mineral staining below it, or a hissing sound when the pump shuts off. But a failing check valve often shows no external leaks. The only reliable test is a pressure test performed by a well contractor, who can measure how quickly pressure drops after the pump stops.
What does a check valve cost to replace?
The valve itself typically costs $50 to $150, depending on the size and material. Labor to remove and install it usually runs $150 to $300. Total cost varies by region and whether the contractor needs to pull the pump from the well (submersible systems) or can access it easily (surface systems).
How often should a check valve be replaced?
A well-maintained check valve can last 10 to 15 years or longer. There's no set replacement schedule—you replace it when it fails. Hard water, acidic water, or frequent power outages can shorten its lifespan. A well contractor can assess the condition of yours during a service call.
Is the check valve the same as the pressure relief valve?
No. The check valve prevents water from flowing backward into the well. The pressure relief valve (usually mounted on the pressure tank) releases excess pressure if the system builds up too much. They serve different purposes and are located in different places.
What happens if the check valve fails completely?
Water will drain from the pressure tank back into the well when the pump shuts off. On the next cycle, the pump has to refill the tank from scratch, which makes it work harder and cycle more frequently. Over time, this can damage the pump motor and shorten its life. The pump may also struggle to build pressure or run constantly.