What You Need to Do Before You Start

Hooking up a well pump means connecting the pump itself to the well casing, the pressure tank, and your home's water lines in the right order. The basic sequence is: pump to well, pump to pressure tank, pressure tank to house. But before you touch anything, you need to know what kind of pump you have and what condition your well is in.

Turn off the power to any existing pump at the breaker. If this is a new installation, make sure your well has been drilled, cased, and tested for water quality and depth. You will need to know your well depth because it determines whether you use a submersible pump (which sits inside the well) or a jet pump (which sits above ground). Most residential wells between 25 and 100 feet deep use submersible pumps. Anything shallower often uses a jet pump.

Gather the parts you will actually use: the pump itself, a pressure tank, check valves, a pressure switch, a pitless adapter (if your well has one), foot valves, and PVC or steel pipe sized to fit your pump's outlet. You will also need Teflon tape, pipe dope (a sealant for threaded connections), and a wrench set. Do not start until you have all of these on hand.

Key Takeaways

  • Submersible pumps go inside the well casing; jet pumps sit above ground—your well depth determines which one you need.
  • The pump connects to the well first, then to a pressure tank, then to your house water lines, with check valves between each section to prevent backflow.
  • All threaded connections need Teflon tape and pipe dope to seal properly and prevent leaks.
  • The pressure switch controls when the pump turns on and off based on tank pressure, and it must be set correctly or the pump will run constantly or not at all.
  • After assembly, you must prime the pump (fill it with water) before turning on power, or the pump will run dry and burn out.

Installing a Submersible Pump in the Well

A submersible pump sits at the bottom of the well casing and pushes water up through a single pipe to the surface. Start by attaching the discharge pipe (the pipe that carries water out) to the pump's outlet. Wrap the male threads with Teflon tape—go around three times, then explore pipe dope over the tape. Screw the fitting hand-tight, then use a wrench to tighten it one more quarter turn. Over-tightening cracks plastic fittings.

Attach a check valve to the top of the discharge pipe before it leaves the well. This valve lets water flow up but stops it from flowing back down when the pump stops. Without it, the column of water above the pump will drain back into the well every time power cuts off, and the pump will have to refill the pipe each time it starts—this wastes energy and causes the pump to cycle too often.

Lower the pump slowly into the well casing on the discharge pipe. Do not drop it or let it bang against the casing walls. As you lower it, you are also running the electrical cable down the side of the casing. Many installers use a cable clamp every 10 feet to keep the cable from tangling or pinching. Stop when the pump sits on the bottom or on the foot valve (a one-way valve that sits at the bottom of the well to keep sediment out).

Setting Up a Jet Pump Above Ground

A jet pump sits in your basement, garage, or pump house and pulls water up from the well through a suction line. This setup works for shallow wells and is easier to service than a submersible pump because you can reach it without pulling it out of the ground.

Install a foot valve at the bottom of the well suction line—this keeps the well from draining and keeps sediment out. Run the suction line (usually 1.25 inches in diameter) from the well to the jet pump inlet, keeping the line as short and straight as possible. Any kinks or bends slow the water flow and make the pump work harder. Attach a check valve right at the pump inlet to prevent backflow.

Connect the discharge line (the line carrying pressurized water out) to the pump outlet. Again, use Teflon tape and pipe dope on all threaded connections. The discharge line runs to the pressure tank. A jet pump is noisier than a submersible pump and requires more maintenance, but it is cheaper upfront and you can replace parts without draining the well.

Connecting the Pressure Tank

The pressure tank stores water under pressure so the pump does not have to run every time you turn on a faucet. Without it, the pump would start and stop dozens of times a day, wearing out much faster. The tank also smooths out pressure spikes that can damage pipes and fixtures.

Connect the discharge line from the pump to the inlet port on the pressure tank. Use a check valve between the pump and tank—this stops pressurized water from flowing backward into the pump when the pump shuts off. Wrap all threaded connections with Teflon tape and seal with pipe dope before tightening.

Most pressure tanks have a small air valve on top (like a tire valve). Before you fill the tank, check the air pressure inside using a tire gauge. It should be about 2 pounds per square inch (psi) less than your pump's cut-in pressure—the pressure at which the pump turns on. If your pump is set to turn on at 30 psi, the tank air pressure should be around 28 psi. If the air pressure is wrong, the tank will not store water efficiently and the pump will cycle too often.

Installing the Pressure Switch and Wiring

The pressure switch is a small device that turns the pump on when tank pressure drops and off when it rises. It screws onto a port on the pressure tank (usually the top). Wrap the threads with Teflon tape and screw it in hand-tight, then tighten with a wrench.

The pressure switch has two adjustment screws inside. The lower screw sets the cut-in pressure (when the pump starts), and the upper screw sets the cut-out pressure (when it stops). The difference between them is called the differential. A typical setting is 30 psi cut-in and 50 psi cut-out, giving a 20 psi differential. Do not adjust these yet—wait until the system is full and running.

The pressure switch connects to the pump motor through a control box (also called a pressure tank switch or pump controller). This box sits between the wall outlet and the pump power cord. It protects the motor from damage if pressure gets too high or too low. Follow the wiring diagram that comes with your switch—usually the switch has two wires that screw into terminals on the control box, and the control box plugs into a standard outlet.

Running Water Lines to Your House

The outlet port on the pressure tank connects to your home's water distribution lines. This is where water leaves the tank and enters your house plumbing. Install a check valve at the tank outlet to prevent water from flowing backward into the tank when the pump is off.

From there, run PVC or copper pipe to your house. Most homes use PVC for underground runs because it is cheaper and easier to install than copper. Bury PVC at least 4 feet deep in cold climates to keep it from freezing. In warmer areas, 2 to 3 feet is usually enough. Slope the line slightly downhill toward the house so it drains if you need to shut it off.

Inside the house, connect the main water line to a shutoff valve near where it enters. This lets you stop water flow to the whole house without touching the pump. From the shutoff valve, run lines to your fixtures—kitchen sink, bathroom, outdoor spigots, and any appliances that need water. Install a sediment filter and a pressure gauge on the main line so you can see what pressure the system is running at and catch sediment before it clogs your fixtures.

Priming and Starting the Pump

Before you turn on the power, you must prime the pump—fill it with water so it does not run dry. A pump running without water overheats and burns out in minutes. For a submersible pump, priming happens automatically as water fills the discharge pipe. For a jet pump, you usually pour water into a priming port on the pump body until water comes out the discharge line, then close the port.

Once the pump is primed, turn on the power at the breaker. The pump should start when ready and begin filling the pressure tank. Watch the pressure gauge on the tank. It should rise steadily from zero to your cut-out pressure (usually 50 psi). This takes a few minutes. Once it reaches cut-out pressure, the pump should stop automatically.

Turn on a faucet inside the house. Water should flow when ready. The pressure should stay steady. If the pump starts and stops every few seconds, the tank air pressure is probably wrong—turn off the power and adjust it. If water does not flow at all, the pump may not be primed, or a check valve may be installed backward. If the pump runs constantly and never shuts off, the pressure switch may be set wrong or the tank may have a leak.

Testing Pressure and Adjusting the Switch

Once water is flowing, check the pressure at the gauge. Turn on a faucet and watch the pressure drop. It should drop to your cut-in pressure (usually 30 psi), at which point the pump should start again. Turn off the faucet and watch the pressure rise back to cut-out pressure (usually 50 psi), where the pump stops. This cycle should repeat smoothly every time you use water.

If the pressure is too high or too low, adjust the pressure switch. The adjustment screws are usually under a cover on top of the switch. Loosen the locknut on the lower screw (cut-in) and turn it clockwise to raise the pressure or counterclockwise to lower it. Make small turns—a quarter turn changes pressure by about 2 psi. Tighten the locknut and test again. Adjust the upper screw (cut-out) the same way if needed, keeping the differential between 15 and 20 psi.

Check all your connections for leaks while the system is running. Leaks at threaded connections usually mean you did not use enough Teflon tape or pipe dope. Turn off the power, drain the tank, tighten the leaking connection, and refill. Leaks at the tank itself or the pump body usually mean a crack or bad seal—those parts need to be replaced.

Frequently Asked Questions

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

You need a pressure tank. Without one, the pump starts and stops dozens of times a day, which wears out the motor and pressure switch in a few years. The tank stores water so the pump runs less often and lasts much longer. It also keeps pressure steady so your fixtures do not get water hammer (banging pipes).

What happens if I install the check valves backward?

Water will not flow, or it will flow very slowly. A check valve has an arrow on the body showing which direction water should flow. The arrow must point away from the pump (toward the tank or house). If it points the wrong way, water cannot get through.

How often do I need to check the tank air pressure?

Check it once a year, usually in spring before heavy use starts. If the air pressure drops below where it should be, the tank has a slow leak and needs to be replaced. Air pressure should never be higher than your cut-in pressure, or the pump will not start.

Can I use a garden hose to connect the pump to the tank?

No. Garden hoses are not rated for the pressure a well pump creates (usually 30 to 50 psi). They will burst or leak. Use rigid PVC or steel pipe rated for at least 100 psi. Hoses can be used for short temporary connections during testing, but not for permanent installation.

What should I do if the pump runs but no water comes out?

First, check that the discharge line is not frozen or clogged. Second, make sure the pump is primed—if it ran dry, it may have lost its prime. Third, check that all check valves are installed with the arrow pointing the right direction. Fourth, look for leaks in the suction line (for a jet pump) that would let air in. If none of these work, the pump impeller may be damaged and the pump needs to be replaced.