Potential dangers from accidents during installation and use are divided into the following threecategories. Closely observe these warnings, they are critical to your safety.Prohibited DisconnectPower Ground Be sure to doRequests to Installers• In order to use the water heater safely, read this installation manual carefully, and follow the in-stallation instructions.• Failures and damage caused by erroneous work or work not as instructed in this manual are notcovered by the warranty.• Check that the installation was done properly in accordance with this Installation Manual uponcompletion.• After completing installation, please either place this Installation Manual in a plastic pouch andattach it to the side of the water heater (or the inside of the pipe cover or recess box if applicable),or hand it to the customer to retain for future reference. Also, be sure to fill in all of the requireditems on the warranty and to hand the warranty to the customer along with the Owner's Guide.WARNING: If the information in this manual is not followed exactly, a fire or explosion may resultcausing property damage, personal injury or death.NORITZ AMERICACORPORATIONInstallation ManualTANKLESS GAS WATER HEATERDANGER indicates an imminently hazardous situation which,if not avoided, will result in death or serious injury.WARNING indicates a potentially hazardous situation which,if not avoided, could result in death or serious injury.CAUTION indicates a potentially hazardous situation which,if not avoided, may result in minor or moderate injury.DANGERCAUTIONWARNINGCAUTIONSBA8655Rev. 12/10NR71-SV, NR66-SV (Indoor/Outdoor Installation, For USA and Canada)NR71-OD, NR66-OD (Outdoor Installation, For USA and Canada)NR50-OD (Outdoor Installation, For USA only)FOR USE IN RESIDENTIAL, COMMERCIAL, OR MANUFACTURED HOMEAPPLICATIONS. (-OD type only)Installation must conform with local codes, or in the absence of local codes,the National Fuel Gas Code, ANSI Z223.1/NFPA 54- latest edition and/orCSA B149.1, Natural Gas and Propane Installation Code (NSCNGPIC).When applicable, installation must conform with the Manufactured HomeConstruction and Safety Standard, Title 24 CFR, Part 3280 or the Cana-dian Standard CAN/CSA-Z240 MH Mobile Homes, Series M86. (NR66-OD,NR71-OD only)Noritz America reserves the right to discontinue, or change at any time, thedesigns and/or specifications of its products without notice.CERTIFIED R*SBA8655*