Reopen the water inlet valve and allow the heater to refill before turning on the electricity again. Step Replace the access panels over the two elements and finally turn on the breaker to the water heater..If you spot a drip, plan to replace the water heater right away. Don’t wait until the leak gets bad. Most residential water heaters cost $ to $ for either gas or electric, plus $ to $ if you have a plumber install it. More expensive gas water heaters with special venting systems also are available..Open the drain valve and empty the water heater into buckets or down a drain. Sometimes opening a water faucet on a sink helps the water heater tank to empty faster..How to install an electric water heater. This Home Depot guide helps you in installing an electric water heater.
Installing the New Water Heater. Place the new water heater in a drain pan. If your water heater did not come with a new T P relief valve pre installed, simply twist in the new valve now. Install the discharge pipe from the T P relief valve toward the floor or drain. Use a flexible hose kit for water hook up..