How to Install a Well Pressure Tank

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If you hear your well pump constantly turning on and off while you have water running or if the water coming out of your tap pulsates, you probably need a new well pressure tank. The tank depends on a bladder of air to work properly. If that bladder fails, the entire tank will fill with water and stop functioning. This often means replacing the tank.


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Before You Begin

Before you go ripping into your plumbing, however, it's best to verify that the well pressure tank is in fact waterlogged. An easy way to tell is to try wiggling the tank a little bit. It will be very heavy if it's full of water. You can also test the tank by opening the pressure release valve. If water spits out rather than air, the tank is full. Tapping on the tank is also helpful, as it should sound hollow wherever there isn't water.

You'll need to purchase the replacement tank before you get started, of course. Make your life easier by purchasing the same size and brand of tank that you currently own. This makes for an easier installation, essentially allowing for a plug-and-play installation rather than spending hours trying to get the right plumbing connectors and configuration.

Things You'll Need

How to Install a Well Pressure Tank

Step 1: Remove the Old Tank

A waterlogged tank is a heavy tank that's hard to maneuver. You'll want to drain the tank before you get too far into the process. Sometimes, however, the air bladder in the tank gets stuck high in the tank and prevents complete drainage. If you have a drain in your basement floor, you can remove the tank, turn it sideways near the drain, and drill a hole in it to release the remaining water. Otherwise, you (and hopefully a helper) will have to remove the tank from the house as is.

  1. Shut off the electrical power to the well pump.

  2. Attach a garden hose to your tank and open the drainage valve to drain the water. Open a few taps in your home as well to make the water drain faster.

  3. Detach the pressure tank from the waterline by loosening the union. Depending on your plumbing, you may have to detach two water lines: the supply line coming into the tank from the well and the line coming out of the tank to your house. These fittings will be tight, so work two pipe wrenches in opposite directions to loosen them if necessary.

  4. Lift the tank up and out and remove it.


Step 2: Prepare the New Tank

Your new water pressure tank will be just that — a tank. It won't have any plumbing attached, so you'll need to attach the water lines yourself. Fortunately, threaded couplings make this task simple. Depending on how your old tank is plumbed, installing the new tank is as simple as screwing the water supply line into the tank itself and then into a single coupling. Some tanks require a T-junction, however, and that requires a bit more setup. Remember to apply plumber's tape to every junction as you work.

  1. Wrap the threaded end of a T-junction in plumber's tape. Thread the junction into the bottom of the pressure tank.

  2. Thread a drain onto the front of the T-junction. Then thread a pressure relief valve onto the front of the junction next to the drain.

  3. Screw a pressure gauge into the opening on the top of the T. Place a pressure switch in the other opening atop the junction.

  4. Thread a female PVC connector onto each side of the T. One will go to the incoming water line and the other to the outgoing line.

  5. Test the pump by placing a tire gauge on the relief valve at the top of the tank. It should read whatever number the instruction manual tells you: typically around 28 psi. If it doesn't, you will need to remove some air from the tank or add some with an air pump.

Step 3: Install the New Tank

Because you were savvy and bought a new pressure tank so much like your old one, installing your new pressure tank is easy. You simply wrap any threads in the plumber's tape and put the plumbing together exactly the way it was before.

  1. Place the water pressure tank into position where the old one was.

  2. Thread the incoming and outgoing water lines into place.

  3. Turn the power to your well pump back on.