Water Heater Closet

• If you have already removed the old water heater, all the power supplies should already be turned off. Clean the floor of debris and water that may have been left behind by the unit you pulled out. Move the new water heater into the closet and position it for the water pipes and power supply. Make sure the unit is level by using a 4-foot level placed across the top. Shim under the legs of the water heater until the unit is completely level.
  
  

New Fittings

• The fittings will have to be connected on the new water heater. You will need to install the temperature and pressure relief valve as well as the discharge drain pipe. The exact locations of these will be in your owner's manual. Use Teflon tape when attaching copper fittings. For galvanized fittings, you will need to use joint compound.
  
  

Connect Water Lines

• Your water lines may not match up exactly to your new water heater. You may need to purchase flexible copper supply lines to remedy the problem. Make sure when you reconnect the water supplies you do not cross inlet and outlet water lines. These will be clearly marked on the new water heater.
  
  

Connect Gas and Electrical Supply

• If you are replacing a gas water heater, you will have to connect the gas line to the gas burner control valve on the new water heater. If you need to add line to make the connection, use flexible gas line, available where you purchased the unit.
  
  After you have connected the gas line, you need to check for leaks. Turn the gas on and brush a soapy water solution on all gas fittings and unions. If the solution bubbles, you will need to tighten down the connection. If, after tightening, you still cannot stop the leak, call a plumber or the gas company for assistance. After all adjustments have been made, turn the gas back off.
  
  On an electrical heater, reconnect all the electrical supply and the ground wire to the water heater's junction box.
  
  

Flue (Gas Water Heater)

• If you are placing a gas heater, you will also need to attach the exhaust flue. Install the flue and the draft diverter, according to the manufacturer's instructions.
  
  

Finish

• After the connections are made, turn the water supply on to the heater. Allow the tank to fill completely. Check for leaks at your water line connections. The tank is full when you can turn on the hot water at a sink and the water flows.
  
  Once the tank is filled, you can turn the power supply back on to the unit, and turn the gas supply on if you are installing a gas water heater.