How To Install an Electric Hot Water Heater

Posted by on Jun 7, 2017 in Uncategorized | No Comments

Before installing a new water heater, consider whether you may simply need repair on your existing one. A licensed plumber can give you a definitive answer on whether or not you can get more life out of the one you have. A water heater will usually last anywhere from 8-12 years, so if it’s been longer than that you most likely should go ahead and replace it. Another thing to consider is the number of people in your household using hot water. If there are less people now, you may be able to install a smaller one or larger one depending on your circumstances. Before beginning, make sure you gather all of the necessary tools and read all warnings associated with installation for your particular model.

Disconnect the Old Water Heater

Shut off the electricity at the circuit breaker. Make sure it’s off by using a voltage tester. This is a very important step because you could save your life by double checking if the 240 volt circuit is indeed off. For convenience when installing the new water heater, use tape to notate the wire connections, and then disconnect the wires.

Let the Water Run Out

Turn on a hot water faucet and let it run until the water is cool. Next, shut off the cold water supply. This will ensure the tank is emptied of water properly. Attach a garden hose to the to the drain valve located near the bottom of the water heater. Open the valve and let the water run out either down a drain or into buckets.

Remove the Old Water Heater

Once the tank is completely empty, it’s ready to be removed. Simply remove the discharge pipe from the T&P (Temperature and Pressure) relief valve, and disconnect the water supply lines. Use a hand truck to remove the tank. You may need assistance from another person for this step of heavy lifting.

Steps to Installing the New Water Heater

  1. Place the new water heater either in a drain pan, or on top of some concrete cinder blocks. This is recommended because if there is a leak or if water pools on your floor where the water heater is located, it won’t damage or ruin it. Make sure it’s level once it’s up off of the floor, and use shims if necessary. In case of a water heater leak, routing a pipe from the drain pan to a drain could also prevent flooding as well.
  2. Most water heaters will come with a new T&P relief valve pre-installed, but if yours didn’t, simply screw in the new one at the appropriate location now. It’s very important that you don’t use the old T&P valve. Purchase a new one if your water heater didn’t come with one.
  3. Wrap plumber’s tape around the threads of the nipples on the pipes that protrude from the water heater. There should be 2, a cold water and a hot water pipe. The tapes helps to provide a leak proof seal.
  4. Connect the water heater to the pipes that carry cold water into and hot water out of the water heater. You will need to refer to your manufacturer’s instructions to make sure you are connecting them properly. Some models have color coded blue and red tubes for cold and hot water. Find out ahead of time if you will need to use dielectric fittings between the hose fittings to prevent corrosion.
  5. Before filling the new tank up with water, make sure the drain valve on the bottom of the water heater is closed. You can now open the valve on the line that feeds cold water into the hot water heater. Next, open the nearest hot water tap, and slowly turn on the water supply. Check all connections going to the water heater for leaks. If there are any leaks, shut off the water supply again and gently tighten the connections.
  6. When water runs out of the faucet, the water tank is full. Make sure you let the water run for 2-3 minutes to bleed any air that is trapped inside the lines. Turn off the taps. Remember, the tank must be completely full before proceeding to electrical wiring or the heating element will be destroyed and render the unit nonfunctional.
  7. Locate the metal plate on top of the water heater underneath which you’ll find the wires you need to connect to. Using wire strippers, remove ½ inch of insulation from each of the wires.
  8. Refer back to the tape you used to notate the electrical wire if needed. Connect the wires according to the manufacturer’s instructions. Connect the bare copper or green wire to the ground screw on the water heater and then wire the 2 additional electrical wires to the corresponding ones you marked with the tape. Use wire connectors to twist them together. Replace the metal plate to cover the wiring.
  9. Set the thermostat on the front of the water heater according to your instructions. 120-125 degrees Fahrenheit is a standard setting used by most households. It may take a few hours for the water heater to reach that temperature.
  10. Turn on the power to the newly installed water heater at the main electrical panel.


-hand truck
-voltage tester
-drain pan or concrete blocks
-plumber’s tape
-garden hose
-wire strippers
-wire connectors


-In areas at risk of earthquake damage, the use of seismic straps to secure the water heater may be required.
-Do not reuse the T&P (Temperature and Pressure) relief valve. You may need to purchase a new one. Note the stem length that is required for your particular model.
-Always fill the water tank up before turning restoring power, or you will destroy the heating elements in the tank.
-Check your homes water pressure using a pressure gauge and make sure it’s between 50-60 PSI. If you home’s water pressure reading is higher, it puts undo strain and stress on your homes appliances.
-Find out if you live in an area where the use of dielectric fittings need to be incorporated into your water heater installation setup. Your area’s local ordinances will dictate the specifics of how to go about doing this correctly.