2ContentsContents ........................................................................................................ 2Owner's GuideImportant Safety Information ....................................................................... 3General PartsMain Unit .................................................................................................... 8Remote Controller .................................................................................... 9Initial Operation ........................................................................................... 11Setting and Using the Water Heater ........................................................... 12Flow Meter Alarm ......................................................................................... 14Muting the Remote Controller .................................................................... 16Preventing Damage from Freezing ............................................................ 17Regular Maintenance ................................................................................... 19Troubleshooting .......................................................................................... 21Follow-up Service ........................................................................................ 25Specifications .............................................................................................. 26External Outfitting ....................................................................................... 27Combustion Unit and Gas Route ............................................................... 29Hot-Water Feed Route ................................................................................. 31Electronic Control Unit ................................................................................ 35Electronic Control Unit, Remote Controller and Attached Set ................ 36Installation Manual ...................................................................................... 371. Included Accessories ............................................................................ 382. Optional Accessories ............................................................................ 383. Quick Connect Multi System Installation ............................................ 394. Before Installation ................................................................................. 405. Choosing Installation Site .................................................................... 406. Installation Clearances ......................................................................... 427. Installation .............................................................................................. 458. Vent Pipe Installation ............................................................................ 469. Gas Piping .............................................................................................. 4910. Water Piping ........................................................................................... 5111. Plumbing Applications .......................................................................... 5212. Electrical Wiring .................................................................................... 5313. Maintenance ........................................................................................... 5714. Trial Operation ....................................................................................... 5715. Dimensions and Wiring Diagram ......................................................... 5816. Multi-System .......................................................................................... 60Remote Controller Installation Guide ........................................................ 64