How to Install an Electric Hot Water Heater
Most water heaters that you will install require 220/240 volts to drive them. The amp load will range between 30 and 60 with most being either 30 or 45. If you are replacing a currently installed unit, more than likely, you will only need a minor amount of material and skill to accomplish this task.
Start by finding the breaker that powers the water heater. Check it to make sure it is rated with at least enough amps and volts to carry the new load. You will find it almost always is. If it is 110/120 volts or low amp load, you may need to replace it. Turn it off. Unscrew the cover that houses the electrical connections. Use a meter to verify that the power is off at the unit.
Disconnect the wires. Turn off the water supply for the water heater. Using an appropriate size wrench, remove the cold water supply and the hot water outlet. You can now hook a hose to the valve on the bottom of the heater and drain it to the nearest place. If you are at ground level or above, you might want to just let it run out on the ground. Do not let the hot water run where someone might be burned by it.
When the heater is empty, you can slide it out of the way and slide the new one into place. This can be done by one person if you are strong enough, but two people make this a much easier job. Once the new unit is in place, if everything lines up, reconnect it. If not, take measurements for the needed pipe alterations and get the materials to complete the hook up.
If your wire is too short, I would recommend that you run new wire from your circuit box so that you do not have a junction that could develop into a fire hazard. It is rare that you would not have plenty of wire, but take care in this area.
Once all of the connections are complete and tight, turn on the water to the unit. Open a hot water faucet in the house to drain the air from the tank and lines. Once water runs freely without air bubbles, turn off the faucet and return to the heater. Check carefully for water leaks and tighten any fittings that are seeping water. Turn on the power. You should hear the elements start to make some sound as they warm up.
If everything is going good, replace the covers over anything that is exposed. The job should be complete except for disposing of the old tank. It should be taken or sent to a landfill or recycling center if one is available.
If you have to install a new heater where it is not a replacement, the procedure is the same except you may have to run the wiring and water lines. If the house has been roughed in for a water heater, everything should be there just like in a replacement situation. If not, then you have some additional work to do.
If you have never ran water or electric, I recommend that you either recruit some serious help with experience or call a professional. It is beyond the scope of this article to tell you how to plumb a house or wire it. However, if the plumbing is in place for the hot water, you will need to run cold water from the nearest point to the utility area where the water heater will sit. Install a cutoff valve on the cold water near the tank so that you can work on the water heater without having the water turned off to the whole house.
Go to the electric panel and install the correct type of breaker to power the new appliance. For 220/240 volts, you will need the double width breaker that attaches to both sides of the circuit box. Attach the ground wires on the correct posts. Buy enough wire to have about 5 to 10 extra feet in case you have to take a route around something that you did not anticipate. Do not attach the breaker in the box until you have complete the connections on the water heater.
Wire everything up, make the water connections and follow the procedure for a replacement unit to complete the job. After all connections are made and leaks fixed, put up your tools and take a hot shower.
