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Install an Electric Water Heater

Install a new, electric water heater in your home and save energy and money. When installing your water heater, make sure to follow model-specific information, warnings, safety notices and local codes. Consult a qualified professional if in doubt.


Preparation

Preparation Tools

You’ll need common plumbing tools and pipe joint compound approved for potable water. You’ll also need a circuit tester or voltmeter. Most codes require the water heater to be installed in a metal drain pan. See the installation instructions for information about sizing the drain pan and other installation details.

If your house has copper pipes, consider an installation kit with compression fittings that don't require soldering. If your pipes are plastic, you’ll need connectors / fittings for the specific type of plastic pipes used in your home. Read the instructions for the new connectors before cutting the existing water pipes.

Locate the circuit breaker marked water heater and turn it off. Some homes use fuses, which should be removed. Your water heater may also have a disconnect switch which should also be turned off.



Drain Your Water Heater

Drain Water Heater

Because circuit breakers can be mismarked, always check the incoming power wires with a voltmeter or circuit tester to make sure the circuit you are working on is off.

Open a hot-water faucet, and let the hot water run until it’s cool. Then, shut off the cold-water supply to the water heater. Leaving the hot-water faucet open will help the tank drain.

Connect a garden hose to the drain valve. Place the other end of the hose in a drain or outside (you could also use buckets). Open the water heater’s drain valve. While the water heater is draining, read the installation instructions that came with your water heater. Disconnect the water and power lines, and remove the old water heater.



Temperature and Pressure Release Valve

Temperature and Pressure Release Valve

Most homes have check valves in the plumbing system and now need a thermal expansion tank installed near the water heater. The expansion tank is attached to the cold-water inlet line. To operate properly, the expansion tank must be pressurized with air. Refer to the expansion tank’s instructions for details.

The temperature and pressure relief valve (T&P) is an important safety device. It opens to relieve pressure if the water temperature or pressure is too high. Use the new T&P that came with your new water heater. Don’t reuse the old T&P valve.

The T&P discharge pipe should be terminated near a floor drain with an air gap of no more than six inches between the end of the discharge pipe and the drain. Some localities require terminating the T&P discharge pipe outside. In cold climates, we recommend using a floor drain. In all cases, follow the codes for your location.

Don't plug or cap the T&P discharge pipe.


Install Hot- and Cold-Water Lines

Install the hot- and cold-water lines. The water heater’s inlet and outlet connections contain nonmetallic parts. Don’t solder pipe directly to these connections. Instead, solder threaded adapters to short pieces of pipe so that soldering is done a foot or so from the water heater connections. Open the cold-water supply valve and fill the tank.

Open a nearby hot-water faucet. At first, you’ll just get air from the faucet, then sputtering, and finally, a full flow. Let the hot water run for three minutes to ensure the tank is completely full. The tank must be completely full of water before connecting electric power, or you'll burn out (dry fire) the upper heating element.



Check for Leaks

Connect the Power Wires

Check the water connections for leaks. Most leaks are due to problems with the inlet or outlet water connections (not a tank leak).

Consult the installation instructions, the wiring diagram and the labels on the water heater. Make sure your home’s wiring and circuit breakers are in good condition and are correct for the model you're installing. Connect the power wires and the green or copper ground wire. The ground wire must be connected to the water heater’s green ground screw.

Review the checklist that came with the installation instructions, and make corrections or repairs as necessary. It’s important that every step has been successfully completed before turning electrical power on.



Set the Thermostat

The upper and lower thermostats are both set at the recommended temperature setting of 120˚F at the factory. Higher temperatures increase the risk of scalding. See the installation instructions and the water heater’s labels for important safety information about scalding.

Replace the insulation, plastic protectors and the upper and lower access panels. Replace the cover on the electrical junction box (on the top of the water heater).

Turn the circuit breaker (or fuses) back on (and the disconnect if you have one). Because the tank is full of cold water, it may take several hours to reach normal operating temperature.



Check Water Pressure

If you have some hot water, but not as much as you’re used to, use a voltmeter and check the incoming voltage. See the wiring diagram and the water heater’s label for power (voltage) requirements. Also, check the temperature setting on both thermostats.

If you have no hot water (not even warm) after a few hours, check to make sure the water heater is getting power. If you have power but no hot water, the upper element may have been dry-fired and will need to be replaced. Replacement elements are inexpensive and widely available.

Drips from the T&P relief valve discharge pipe usually mean you need a thermal expansion tank or your home’s water pressure is too high.

Don't plug or cap the T&P discharge pipe.