BTH-120 through BTH-500 Instruction Manual Brandname: A.O. Smith Category: Water Heater Total Pages: 80 Table of contents TableOfContents2Approvals3GeneralSafetyInformation4GeneralSafetyInformation5Introduction6FeaturesAndComponents7InstallationConsiderations11Caution12InstallationRequirements14Caution16VentingInstallation22