Rheem Marathon Point-of-Use Series Use and Care Manual - Page 14

Maintenance 3. HEATING ELEMENTS - Most water supplies will cause scale or mineral deposits to form on the heating elements. As the scale forms, it gets increasingly harder for the element to heat water. If you hear a rumbling noise coming from the water heater, it is probably caused by scale build up on the elements. Element life can be lengthened by installing a water softener or other water treating equipment that removes most of the minerals that cause scale. G. To expose the element for removal, lift up the hinged portion of the thermostat protective cover by gently pulling the lower corners up and away from the thermostat. Be careful to avoid pulling the thermostat from its mounting bracket, or bending the thermostat bracket. H. After again insuring that the electrical power is off, disconnect the two wires from the element terminals. (See Figure 15). TO REPLACE BURNED OUT ELEMENTS - IMPORTANT! - The elements used in this water heater are different than standard replacement elements. It is important to note that STANDARD REPLACEMENT ELEMENTS WILL NOT FIT THIS WATER HEATER! Proper replacement elements are available at your local retail outlet or service center. Be sure to refer to parts illustration supplied with the heater for proper identification of replacement elements. Care must be taken to insure that the correct element is being used. The tank warranty may be voided if the wrong element is used. Heating Element Up Arrow Wiring Terminals ! CAUTION Before starting to remove an Element, be sure to turn the power supply to the water heater "OFF" at the electrical distribution panel. A. With the power supply turned "OFF", close the shut-off valve installed in the cold water supply pipe. B. Open a nearby hot water faucet and KEEP OPEN. C. Fasten a length of garden hose to the drain valve. Place the other end of the hose at a floor drain, or other suitable location. (See FIg. 12 ) D. Open the drain valve and drain the heater until the water level in the tank is below the element needing replacement. ! DANGER The water drained from the tank may be hot enough to present a SCALD HAZARD and should be directed to a suitable drain to prevent injury or damage. E. Close the drain valve and remove the hose. F. Remove the thermostat snap-in access panel cover. Insert finger into latch hole on the bottom of the cover, and push up to release the latch. Then pull forward to remove the cover and insulation. Remove the four (4) screws securing the thermostat access panel and the two (2) thermostat insulation pads, exposing the thermostat. (See Figure 14.) Thermostat Insulation (2) Access Panel Cover Figure 15. - Typical Element Wiring I. With wires removed from the element terminals, remove the old element by using a "1/2 socket wrench on the 4 hex screws. J. Clean the gasket sealing surfaces of the water heater prior to preparing to install the element with a new gasket. Look at the elements mounting flange and orient the element so that the up arrow points up (See Figure 15) and insert it into place. Note that the elements tubes are stepped downward and they must be installed so they are closest to the bottom of the water heater. Insert and tighten the 4 hex screws and washers evenly. NOTE: Be sure the gasket sealing surface is clean. Wet the new gasket with water to lubricate and make a good seal. K. Close the water heater drain valve and completely fill tank with water. Check the element for leaks. Repairs any leaks as needed. L. Reconnect wiring to the terminals on the element (see FIgure 15). ! WARNING Failure to properly tighten element terminal screws can cause a fire which can result in property damage, bodily injury or death. M. Lower the hinged portion of the thermostat protective cover to cover the element and its wiring connections. ! WARNING Thermostat Access Panel Cover Cover Insulation Access Panel Latch Hole Figure 14 - Removing Access panel for replacement of element. Make sure the thermostat is flush against the thermostat mounting plate, and the protective cover is in place before replacing the insulation pads and access cover. Failure to do so can result in property damage, bodily injury or death. N. Replace the two pieces of fiberglass insulation over the thermostat and attach the thermostat access panel. Replace the single piece of insulation in the thermostat access panel cover and snap it into position. O. Turn on the electrical power supply to bring the heater into service again. 12