11Illustration6. InstallationCheck4. Drill holes for the remaining four screws.5. Hang the unit again by the first screw, and theninsert and tighten the remaining four screws.6. Take waterproofing measures so that water doesnot enter the building from screws mounting thedevice.• Make sure the unit is installed securely so that it willnot fall or move due to vibrations or earthquakes.Securing to the wallMounting Bracket(upper)Tapping ScrewLocation of Screw Hole1. Drill a single screw hole, making sure to hit a stud.2. Insert and tighten the screw and hang the unit bythe upper wall mounting bracket.3. Determine the positions for the remaining four screws(two for the top bracket and two for the bottom), andremove the unit.• The weight of the device will be applied to the wall. If the strength of the wall is not suffi-cient, reinforcement must be done to prevent the transfer of vibration.• Do not drop or apply unnecessary force to the device when installing. Internal parts maybe damaged and may become highly dangerous.• Install the unit on a vertical wall and ensure that it is level.Locating Screw HolesLocating Screw HolesMountingStructure• When installing with bare hands, take caution tonot inflict injury.• Be careful not to hit electrical wiring, gas, or waterpiping while drilling holes.ItemCAUTIONBe sure to doInstallations at ElevationsAbove 610m (2,000').HIGH ELEVATIONDISCONNECT• If this water heater is being installed at an elevation of610m. (2,000') or higher, disconnect the connector la-beled "High Elevation Disconnect" as illustrated on theright. This connector is located inside the unit.• Disconnect power to the water heater before discon-necting this connector. Failure to perform this step willresult in a flashing light on the unit or a "73" code dis-played on the optional remote controller and a ceasein operation. If this occurs, disconnect, then reconnectpower to the water heater to reset the system.