HIGH ALTITUDE INSTALLATIONS WARNING INSTALLATIONS ABOVE 2000 FEET REQUIRE REPLACEMENT OF THE BURNER ORIFICE IN ACCORDANCE WITH SECTION 8.1.2 OF THE NATIONAL FUEL GAS CODE (ANSI Z223.1). FOR CANADIAN INSTALLATIONS CONSULT CANADIAN INSTALLATION CODES AND CAN/CGA B149. FAILURE TO REPLACE THE ORIFICES WILL RESULT IN IMPROPER AND INEFFICIENT OPERATION OF THE APPLIANCE RESULTING IN THE PRODUCTION OF INCREASED LEVELS OF CARBON MONOXIDE GAS IN EXCESS OF SAFE LIMITS WHICH COULD RESULT IN SERIOUS PERSONAL

3. A common ground is required for the S93XX and the main burner. The 24V “secondary” plug internally grounds one side of the transformer. Any auxiliary controls or limits must not be in the grounded leg. In addition, the appliance should be earth-grounded. 4. Make sure the transformer has adequate VA. The ignition module requires at least 0.2A at 24 Vac. Add the current draws of all other devices in the control circuit, including the gas control, and multiply by 24 to determine the total VA req

No duplication or reproduction of this book may be made without the express written authorization of the A.O. Smith Water Products Company. The following text and illustrations will provide you with a step by step procedure to verify proper installation, operation, and troubleshooting procedures. Additional quick reference data is included to assist you in servicing this product. The information contained in this handbook is designed to answer common questions encountered in the operation of the

• Safety Instructions • Installation • Operation PRINTED IN THE U.S.A 0410 PART NO. 315456-002 ALL TECHNICAL AND WARRANTY QUESTIONS: SHOULD BE DIRECTED TO THE LOCAL DEALER FROM WHOM THE WATER HEATER WAS PURCHASED. IF YOU ARE UNSUCCESSFUL, CONTACT RESIDENTIAL TECHNICAL ASSISTANCE AT 1-800-527-1953 OR WWW.HOTWATER.COM. — Do not store or use gasoline or other flammable vapors and liquids in the vicinity of this or any other appliance. — WHAT TO DO IF YOU SMELL GAS • Do not try to light any applianc

™ CATEGORY IV LISTED • Requires AL29-4C gas tight rust resistant venting material PROFESSIONAL START-UP SERVICE FURNISHED • Assures optimum performance for each installation MEETS ASHRAE/IESNA 90.1-1999 5 YEAR HEAT EXCHANGER WARRANTY • For complete information, consult written warranty or contact A. O. Smith OTHER VF™BOILER FEATURES: • ASME 160# W.P. • ASME PRESSURE RELIEF VALVE 125# • FACTORY MOUNTED FLOW SWITCH • MEETS CSD-1 CODE-–FACTORY STANDARD • BRASS DRAIN VALVE • LOW GAS PRESSURE SWITCH

8 Air Requirements ........................................................................... 8-9 Venting ........................................................................................... 9 Relief Valve .................................................................................... 9-10 Hard Water ..................................................................................... 10 Closed Water System .................................................................... 10 Wate

A low water cutoff device of the float type should be flushed every six months. 6 DRAIN VALVE (Not Supplied) Additional drain valves must be obtained and installed on each boiler and tank for draining purposes. SAFETY RELIEF VALVES Your local code authority may have other specific relief valve requirements not covered below. WARNING THE PURPOSE OF A SAFETY RELIEF VALVE IS TO AVOID EXCESSIVE PRESSURE WHICH MAY CAUSE TANK EXPLOSION, SYSTEM OR BOILER DAMAGE. TOAVOID WATER DAMAGE A DRAIN LINE MUST B