How to Change a Thermo Rheem Water Heater

Removing the Old Unit

• 1

  Shut off the gas or electricity to the unit. Shut off the electricity at the household breaker panel by flipping the breaker to the circuit for the water heater or by pulling out the fuse. Then unplug the unit from the wall. For a gas model, turn the main valve clockwise to shut off the gas. Some valves will not tighten in the "Off" position. For these, rotate the valve one full turn clockwise. Be sure to unplug the unit from the wall outlet.

• 2

  Turn off the water at the source. Either shut off the water at the wall outlet where the tank is connected or turn off the main source to the house at the water main.

• 3

  Drain the tank. Turn on a hot water tap at a nearby sink or tub and allow it to run for several minutes. Locate the drain at the bottom of the unit and remove the plug. Drain the water into a bucket or a floor drain if available or attach a garden hose to run the water outside or into a washtub. Be careful as the water may be hot.

• 4

  Remove the vent. For gas units, there may be a hood and vent connected at the top. Unscrew the bolts in the metal vent and remove the assembly.

• 5

  Unplug any electrical units from the water heater or unscrew the gas lines. For a gas model, use an adjustable wrench to detach the line at the connection closest to the unit. Turn it slowly and listen for the gas to release. The flow of gas should stop within moments if the gas is turned completely off. If it continues, tighten the line back up and call a professional.

• 6

  Remove the water pipes. All tanks will have an incoming and outgoing water line. Use the adjustable wrench to loosen and remove each of the lines at the connections closest to the unit. Water will drain from the pipes so have a bucket ready. If the unit does not have threaded connectors, you will have to cut the pipes with a hacksaw to remove them then replace the piping with flex connectors. At this point you can remove and dispose of the old water heater.

Installing the Rheem Unit

• 7

  Place the new water heater in the same location as the old unit. This helps minimize the need for additional plumbing or energy lines.

• 8

  Attach the vent for a gas unit. Place the hood at the top of the unit onto the existing vent duct and screw it into place. Inspect the vent duct to ensure no rust or thin spots are present. If any wear is noticed, replace the vent ducts.

• 9

  Connect the water lines. On Rheem tank-less models, the incoming and outgoing water lines are each positioned at the top of the unit; they will be marked accordingly. On tank models, the incoming line will be at the bottom of the unit and the outgoing at the top. It may be necessary to turn the new unit to align the old plumbing. Use the new connectors, which come with the unit, and channel-lock pliers or the adjustable wrench to connect the lines.

• 10

  Plug in an electric water heater at the wall outlet. For a gas model, connect the gas lines to the unit with the adjustable wrench and plug in the secondary power cord to the wall outlet.

• 11

  Restore power to the unit. For electric water heaters, this only requires flipping the breaker back on or reinstalling the fuse. For gas models, your utility company should be called to inspect the connection, turn on the gas and light the pilot for the unit.

• 12

  Turn on the water source. Check the unit for leaks. A tank-less unit does not require time to heat the unit. For a unit with a tank, allow at least 15 minutes for the heater to provide hot water.