Installing a new hot water heater is generally a much easier job than many homeowners think, especially if the new water heater is of the same type (gas or electric) as the previous heater.\nIf a homeowner is switching from an electric heater to a gas heater or vice versa then electrical or gas lines may need to be installed.
How to Install a Hot Water Heater
Shut off the water connection to the old hot water heater. This can usually be done by simply shutting off a valve on the water line leading directly to the water heater. Shut off the gas line by turning the knob on the gas line so the knob is perpendicular to the line. Unplug the old heater if it is electrical.
Connect a hose to the drain valve at the bottom of the heater and run the hose to an outside location. Open the drain valve on the heater and allow the water to drain out.
Unscrew the water inlet fitting and the water outflow fitting on the top of your heater using your pipe wrench and your crescent wrench. It will take the use of both wrenches to unscrew the fittings. If you are removing a gas water heater you will need to use both wrenches to unscrew the fitting for the gas line as well.
Remove the flue hat on top of your tank so that the tank is no longer connected to the vent pipe. \nRemove the old heater and discard properly as per codes and regulations in your area.\nSet the new heater in place and level it using shims if necessary. Make sure all controls on the new unit are accessible.
Wrap the threads of the water inlet and the outlet fittings on top of the tank with pipe tape and screw on the water inlet line and the outlet line to the top of your new unit using both of your wrenches. Open the water line to fill the tank. Open several water faucets in the house to allow air to bleed out of the tank as it fills with water.
Connect the gas line to the new tanking using both of your wrenches or plug the unit in if it is electrical. If you have just switched to an electrical heater from a gas heater make certain that you are plugging your new unit unto an outlet of the proper voltage for your water heater.
Reconnect the flue hat to the top of your new tank so that your tank is properly vented.