How to Install a Hot Water Expansion Tank

  • 4-8 hours
  • Advanced
  • 50-500
What You'll Need
Pipe Wrench
Water heater Expansion Tank
Teflon Tape
Drilling Machine
Tee Fitting

A hot water expansion tank is a very important part of a water heater. When water is heated it expands and needs a place where it can safely overflow to. If there is no expansion tank, the pipes could begin to leak or burst. Installing a hot water expansion is job you can do yourself, with the right tools and this guide you will be able to successfully install your hot water expansion tank.

Step 1 – Shut off the Water Supply

The first step in installing a hot water expansion tank is to shut off the water supply to your heater. If you have a shut off valve located on the supply line for your water heater, close it or shut off the water from the main supply line to your home.

Step 2 – Turn off the Power Supply

If your water heater uses electricity, turn off the breaker that supplies electricity to your water heater.

Step 3 – Turn off the Gas

If your water heater uses gas to heat the water, you will need to turn off the gas supply to the heater. If you do not know how to turn off the gas supply, contact your gas company and seek assistance.

Step 4 – Size of the Expansion Tank

Decide on the size of the expansion tank you are going to buy, a good idea is to check the capacity of your water heater and buy the expansion tank. You can verify the right size at the hardware store.

Step 5 – Other Accessories

While you are at the hardware supply store, buy the Teflon tape and the tee fitting. You might also need to buy the mounting brackets and a couple of 1 ½ inch screws.

Step 6 – Cold Water Supply Line

Find the cold water line and check which one is horizontal to the hot water heater. This is the water supply line you will need to connect to your water heater.

Step 7 – Placing the Expansion Tank

Position the expansion tank above the cold water supply pipe. From there it should be assessable to the water heater.

Step 8 – Fix the Tank

Mark the place where the mounting brackets will go on the wall and drill holes. Fix the expansion tank on the wall.

Step 9 – Tee Fitting

Connect the tee fitting to the pipe that supplies cold water.

Step 10 – Connect the Tank

Wrap Teflon tape around the end of the connector of the expansion tank and fix it to the tee fitting. Tighten it with a wrench but make sure you do not over tighten it and break it.

Step 11 – Water and Power Supply

Turn on the water supply and switch on the breaker that supplies electricity to the heater. If you use gas for your water heater, reconnect the gas piping and turn on the gas.

Step 12 – Check the Expansion Tank

Once the tank is filled and the heater is on, open a faucet and check if hot water flows from the faucet.