What You Need

Tools: Pipe wrenches, hacksaw or tubing cutter, screwdriver, hammer, appliance dolly, level, adjustable wrench, neon circuit tester, propane torch.
Materials: Bucket or garden hose, wood shims, pressure-relief valve, masking tape, lead-free solder.




Material taken from
Black and Decker "Home Repair"

Installing an Electric Water Heater

When you buy a new electric water heater, choose one with the same voltage as the old model, and remember that pressure-relief valves usually must be purchased separately. Make sure the valve you buy matches the working pressure rating of the tank. Water heaters are available with tank sizes ranging from 30 to 65 gallons. A 40-gallon tank typically is large enough for a family of four.

Turn off the power to the water heater by switching off the circuit breaker (or removing the fuse) at the main service panel (photo A).

Remove one of the access panels on the side of the tank (photo B). Wearing protective gloves, fold back the insulation to expose the thermostat (photo C). Do not touch the bare wires until you have tested them for current.

To make sure there is no power to the unit, test for current by touching the probes of a neon circuit tester to the top pair of terminal screws on the thermostat (photo D). If the tester lights, the wires are not safe to work on; turn off the main power switch and retest for current.

Open the hose bib on the side of the tank to empty the tank. Drain the water into buckets or attach a hose and run it to a floor drain.

Disconnect the hot and cold water pipes above the water heater. If the pipes are soldered copper, use a hacksaw or tubing cutter to cut through them, just below the shutoff valves. It's important to make straight cuts so the fittings will be watertight when you connect the new water heater.

Remove the cover plate on the electrical box, located at the side or top of the water heater (photo E). Label all wires with masking tape for reference, then disconnect them. Loosen the cable clamp, then remove the wires by pulling them through the clamp. Using an appliance dolly, remove the old unit, then put the new one in place.

Wrap Teflon tape around the threads of a new pressure-relief valve. Using a pipe wrench, screw the new valve into the tank opening.

Measure the distance between the pressure-relief valve and the floor. Cut a length of copper or CPVC drain pipe that will reach to within 3" of the floor. Attach the pipe to the pressure-relief valve, using a threaded male adapter.

Solder a threaded male adapter to each of the water supply pipes. Let the pipes cool, then wrap Teflon tape around the threads of the adapters.

Wrap Teflon tape around the threads of the two heat-saver nipples. Look closely at the nipples—they're color coded and have directional arrows to help you install them properly.

Attach the blue-coded nipple fitting to the cold water inlet and the red-coded fitting to the hot water outlet, using a pipe wrench. Install the cold water nipple with the water direction arrow facing down; install the hot water nipple with the arrow facing up.

Connect the water supply pipes to the heat-saver nipples with flexible water connectors (photo F). Tighten the fittings with an adjustable wrench. To restore the water supply, open the hot water taps at faucets throughout the house, then open the water heater inlet and outlet shutoff valves. When the water runs steadily from all the faucets, close them.
Remove the electrical box cover plate on the new water heater (photo G). Thread the circuit wires through the clamp, then through the cable opening on top of the water heater. Attach the clamp to the water heater.

Connect the circuit wires to the water heater wires, using wire connectors (photo H).
Attach the bare copper or ground wire to the ground screw on the unit (photo I). Replace the cover plate

Use a screwdriver to set the thermostat to the desired water temperature, 120° to 125°F (photo J). If the unit has two elements, set both thermostats.

Press the reset button on each thermostat (photo K). Replace the insulation and access panels, and restore power to the unit.