How to Replace a Water Well Pressure Tank

A downward view of a well pump system.
What You'll Need
New tank
Teflon tape

If you live in an area that is not supplied with a water main system, then you will probably be using a water well pressure system instead. These water wells use a powerful pump that requires a pressure tank to operate it, as there is a loss of compressed air beneath the ground. However, sometimes these tanks can wear down, spelling trouble for your water system.

If you have a tank that needs to be replaced, you can either have it done by a plumber, at some cost to yourself, or you can attempt to do it on your own. If you feel that you have the right home improvement skills to go ahead with this task, then following the steps can help you to get started.

Step 1 - Turn off the Supply

Before you begin to do anything else, you should ensure that your water and electrical are turned off at the well. It's best to remove the circuit breaker for the pump completely, as this prevents any unfortunate surges.

Step 2 - Drain the Tank

You will now need to locate your pump and pressure tank. These can sometimes be found in the basement, or in a cupboard under the stairs. Once located, you should drain the system of water. This can be done using a hose and an old bucket and can take between five and 20 minutes, depending upon how much water is in the system.

Step 3 - Remove the Old Tank

Take off the cap covering the pressure switch, and remove the wires which are connecting the supply lines. Once it is disconnected, use your wrench to loosen the pipes that connect the pressure tank to the well pump. You may need to do this while holding them upright so that the tank doesn't tip over.

Once you have disconnected the switches, pipes, and everything else, the tank should be able to be removed with a twisting-walking motion, such as you might use to get a fridge into the right position. Lay it down once it's out and remove all of the piping, including pressure gauges and the pressure switch. Then, set it aside to make room for the new one.

Step 4 - Fit the New Tank

You can reconnect the pressure switch and gauge to the new tank using a piece of Teflon tape. Make sure to place the tape around in the same direction as the screw turn, so that it won't be peeled off while re-attaching. You can install new pieces if you wish, but if they are working well, then there is no real reason to spend the extra money.

Put the new tank into position, and join the fittings back together, so that the tank is once more connected to the water pump. Reconnect the wires at the pressure switch. Once the pipes are sealed back together, and the switch is reattached, then you can turn on the mains again, and check that the pump is working.