What a shallow well pump installation involves

Plumbing a shallow well pump means connecting the pump to your well, running water lines to your house, and setting up the pressure tank and check valves that let you use water on demand. The work breaks into three main parts: mounting the pump above ground (or in a pump house), running the suction line down into the well, and connecting the discharge line to your pressure tank and home plumbing.

A shallow well pump sits above ground and pulls water up from the well through a suction line—it cannot push water down. This is why depth matters: shallow well pumps work on wells up to about 25 feet deep, though 20 feet is more reliable. If your well is deeper, you need a submersible pump instead, which sits in the water and pushes it up.

This is not a job to rush. A leak in the suction line will let air in and break the pump's prime. A missing check valve will drain your pressure tank every time the pump stops. A loose fitting will spray water across your pump house. The steps are straightforward, but each one has to be done right the first time.

Key Takeaways

  • A shallow well pump must be mounted on a solid, level base above ground, with the suction line running down into the well at a slight downward angle to prevent air pockets.
  • Every joint in the suction line must be airtight—use thread seal tape and tighten fittings by hand first, then with a wrench, and test for leaks before you start the pump.
  • A check valve must go on the discharge line between the pump and pressure tank to prevent the tank from draining back into the well when the pump stops.
  • The pressure tank, pressure switch, and relief valve work together to turn the pump on and off automatically—if any of these is missing or set wrong, the pump will run constantly or not at all.
  • If the pump loses prime (stops pushing water), you will need to refill the pump housing with water and restart it; this happens when air enters the suction line.

Choosing the right location and base for your pump

The pump must sit on a solid, level concrete pad or platform, not on dirt or gravel. Vibration from the pump will settle it unevenly over time, and an unlevel pump will trap air in the suction line. Pour a concrete pad at least 4 inches thick and large enough for the pump and motor to sit flat, with room to work around them. If you are building a pump house, make sure the floor is concrete, not wood.

The pump should be as close to the well as practical—every foot of suction line adds friction and makes it harder for the pump to pull water up. Ideally, keep the suction line under 20 feet long. The pump also needs to be above the highest water level in the well, and it needs protection from freezing if you live in a cold climate. A small insulated pump house or a buried line with a heat tape will prevent freeze damage in winter.

Make sure the location has good drainage so water spilled during maintenance does not pool around the pump. You will also need access to electricity for the motor and room to service the pump, pressure tank, and valves without having to move equipment.

Running the suction line from the well to the pump

The suction line is the pipe that runs from the well down to the water and back up to the pump inlet. It must be airtight—any leak will let air in and break the pump's prime. Use rigid PVC pipe or galvanized steel pipe, not flexible hose, because hose can collapse under the vacuum the pump creates. Typical sizes are 1.25 inches or 1.5 inches in diameter.

At the bottom of the suction line, attach a foot valve—a one-way check valve with a screen that sits in the water and lets water in but not air. The foot valve is what keeps water in the line when the pump stops, so the pump does not have to re-prime every time it starts. Screw the foot valve onto the bottom of the suction line before you lower it into the well.

Lower the suction line into the well slowly and carefully. It should angle slightly downward from the pump to the well—never upward, because air will collect in the high spots. Once the foot valve is submerged, find the suction line at the well opening so it cannot move or kink. Use a clamp or strap, not just gravity.

At the pump end, connect the suction line to the pump inlet using a union fitting (a two-part connector that lets you disconnect the line later without unthreading the whole thing). Wrap the male threads with thread seal tape—go around three times—and tighten by hand first, then with a wrench. Hand-tight plus one-quarter turn with a wrench is the right amount; over-tightening cracks fittings.

Installing the discharge line and check valve

The discharge line carries water from the pump outlet to the pressure tank. Between the pump and the tank, you must install a check valve—a one-way valve that lets water flow toward the tank but not back toward the pump. Without it, the pressure tank will drain back into the well every time the pump stops, and you will lose pressure.

Connect the discharge line to the pump outlet using a union fitting, just as you did with the suction line. Then connect the check valve to the discharge line, with the arrow on the valve pointing toward the tank. Use thread seal tape on all male threads. Tighten each fitting by hand first, then with a wrench.

Run the discharge line to the pressure tank. It can be buried, run above ground in a trench, or run through a pump house—whatever keeps it protected from freezing and damage. The line should slope slightly downward toward the tank so air does not collect in high spots. If the line must go uphill to reach the tank, install a small air vent at the high point so trapped air can escape.

At the tank, connect the discharge line to the tank inlet. Most tanks have a threaded port on top or the side. Use a union fitting here too, so you can disconnect the line if you need to service the tank.

Setting up the pressure tank and pressure switch

The pressure tank stores water under pressure so the pump does not have to run every time you turn on a faucet. It also contains a rubber bladder or diaphragm that separates the water from a cushion of air. When you first install the tank, you may need to add air to the bladder through the air valve on top—check the tank manual for the correct pressure, which is usually 2 pounds per square inch below your pump's cut-in pressure.

The pressure switch is mounted on a tee fitting attached to the tank. It senses the water pressure inside the tank and tells the pump motor when to turn on and off. A typical setting is cut-in at 30 pounds per square inch (the pump starts) and cut-out at 50 pounds per square inch (the pump stops). These settings are adjustable with nuts on the switch, but do not change them unless you have a reason—the factory settings work for most homes.

A relief valve must also be installed on the tank, usually on the same tee as the pressure switch. The relief valve opens if pressure gets too high and lets water out, protecting the tank from over-pressurization. It is usually set to open at 10 pounds per square inch above the cut-out pressure—so if the pump cuts out at 50 pounds, the relief opens at 60 pounds.

Priming the pump and testing for leaks

Before you start the pump, you must fill the pump housing with water—this is called priming. The pump cannot pull air; it needs water in the housing to create the vacuum that pulls more water up from the well. Remove the priming plug (usually a square nut on top of the pump) and pour water in until it overflows. Replace the plug and tighten it firmly.

Now turn on the pump and listen. You should hear water flowing into the pressure tank. Watch the pressure gauge on the tank—it should climb from zero to your cut-out pressure (usually 50 pounds per square inch), then the pump should stop. If the pump runs for more than a minute without building pressure, turn it off when ready. The pump has lost prime, which means air is in the suction line.

If the pump loses prime, turn it off, remove the priming plug again, refill the housing with water, and restart. If it loses prime a second time, there is a leak in the suction line. Check every fitting for water dripping out. Tighten any loose fittings with a wrench. If you find a leak, turn off the pump, drain the line, fix the leak, refill, and prime again.

Once the pump builds pressure and shuts off, turn on a faucet in the house and watch the pressure gauge drop. When it reaches your cut-in pressure (usually 30 pounds), the pump should start again. If it does not, the pressure switch may be stuck or set wrong—check the manual or call a pump technician.

Troubleshooting common plumbing problems

If the pump runs constantly and never shuts off, the pressure switch is not sensing the tank pressure. Check that the line from the tank to the pressure switch is not kinked or blocked. If the line is clear, the switch may be faulty and need replacement.

If the pump starts and stops every few seconds (called short-cycling), the pressure tank may have lost its air charge. Turn off the pump, drain the tank, and add air through the air valve using a bicycle pump or compressor. The air pressure should be 2 pounds per square inch below your cut-in pressure.

If water sprays from a fitting when the pump is running, turn off the pump when ready and let the pressure drop. Then tighten the leaking fitting with a wrench. If tightening does not stop the leak, turn off the pump, drain the line, unscrew the fitting, wrap the male threads with more thread seal tape, and reconnect.

If the pump primes but then loses pressure and stops, the check valve may be stuck or leaking. This is harder to diagnose without a pressure gauge on both sides of the valve. If you suspect a bad check valve, turn off the pump and call a pump technician.

When to call a professional

You can handle the basic plumbing—connecting pipes, installing valves, and priming the pump. But if the pump will not build pressure after two priming attempts, if water is spraying from multiple fittings, or if the pressure switch will not turn the pump on and off, stop and call a pump technician. These are signs of a deeper problem: a cracked pump housing, a bad foot valve, or an electrical issue with the switch.

Also call a professional if your well is deeper than 25 feet or if you are not sure of the depth. A shallow well pump will not work on a deep well, and installing the wrong pump wastes money and time.

Frequently Asked Questions

How do I know if my well is shallow or deep?

Measure the distance from the top of the well to the water surface. If it is 25 feet or less, a shallow well pump will work. If it is deeper, you need a submersible pump. You can also ask the previous owner or check your well permit, which usually lists the depth.

What size pump do I need?

Pump size depends on how much water your house uses and how fast you want the tank to fill. A typical household uses 3 to 5 gallons per minute. A 0.5 horsepower pump delivers about 5 gallons per minute; a 1 horsepower pump delivers 8 to 10 gallons per minute. Bigger is not always better—an oversized pump will short-cycle and wear out faster.

Can I use flexible hose instead of rigid pipe for the suction line?

No. Flexible hose will collapse under the vacuum the pump creates, and the pump will lose prime. Use rigid PVC or galvanized steel pipe only.

What should I do if the pump loses prime in winter?

Freezing temperatures can freeze water in the suction line and break the prime. Insulate the pump house, bury the suction line below the frost line, or use a heat tape on the line. If the line freezes, thaw it with warm water or a heat gun before restarting the pump.

Do I need a pressure tank, or can the pump push water straight to the house?

You need a pressure tank. Without it, the pump will run every time you turn on a faucet, which wears out the motor and switch. The tank stores water and pressure so the pump can rest between uses.