How to Replace a Well Pressure Tank in 6 Steps

When shopping for a replacement, it’s best to choose the same well pressure tank size and brand as your old tank. This helps ensure a relatively easy installation because you’ll be using the same connections, which saves you considerable time, energy, and unnecessary stress. 

Your well pressure tank will likely be one of these three types:

• Bladder tank: This pressure tank is among the most common and uses a bladder to pressurize air above the tank’s water.

• Air-over-water tank: Consisting of a single chamber, an air-over-water tank is filled with pressurized air and water, however, there is no bladder or diaphragm separating the two.

• Diaphragm tank: A diaphragm tank features a permanently attached barrier, which expands as water enters the tank, creating pressurized air.

Start by cutting the power to the well pressure tank. Switch off the circuit breaker to the well pump from your home’s electrical panel, and turn off the electrical box located near the tank.

If your tank is waterlogged, it will make it heavy and difficult to move, so it’s important to drain it before going any further. To test if your water pressure tank is waterlogged, open the pressure release valve at the top of the tank, and use the tip of a screwdriver to press the valve down gently. If water jets out, your tank is full of water. Another option is to give your tank a couple of taps—a hollow sound means little to no water. 

To drain your tank, attach a garden hose to the drain valve, then open the valve to release the water into a large bucket, or use the floor drain in your basement. To speed up the process, open a few faucets in your bathroom and kitchen while draining. 

Once the tank is drained, remove the pressure switch cap and disconnect the wires. Use a pipe wrench to loosen the ring nut on the union where the inlet pipe connects to the tank. Then, loosen the ring-nut union to the outlet pipe using the same process. Don’t remove the nuts as you’ll need these for securing your replacement tank.

If your pressure tank is fastened to a concrete pad, loosen and remove the bolts with a socket and ratchet in order to lift it free.

With the old tank removed, you’ll need to get the replacement tank prepped in order to install it. If the T-junction pipe connected to the bottom of your old tank is in good shape, you can use it with your new tank. 

Wrap the threaded end of the pipe with Teflon or vinyl plumber’s tape, then insert it into the bottom of your tank and tighten it with a pipe wrench. Make sure the end of the pipe is facing the right way, so it will connect with your home’s water line.

Be sure to wrap the plumber’s tape around all threaded junctions, including the inlet and outlet pipes, as you go to make connections easier.

If your new pressure tank is exactly the same as your old one, replacing it will be a breeze. Position it in the same spot as your old tank and thread the inlet pipes, outlet pipes, and the water line into place, tightening them with a pipe wrench. 

If you have a concrete pad, use a socket and ratchet to anchor bolt the tank down. With everything fastened to the tank, reconnect the wires to the pressure switch. Turn on the circuit breaker to your well pump. Allow the tank to fill with water until the pump shuts off before using your home’s faucets.