• 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

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

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

™ 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

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

B. If the reading taken is less than 1.7 million ohms, and the wiring from the control to the sensor is good, replace the lower control. 12. “FV-SENSE” and “SHORT” Flashing Flammable Vapor Sensor is shorted 1. Check all wiring to the flammable vapor sensor. 2. Remove the connectors from the flammable vapor sensor and measure the resistance of the sensor with an ohmmeter. A. If the reading taken is less than 2000 ohms, replace the flammable vapor sensor. B. If the reading taken is more than 2000

Gasket, Port (1/8" Thick)...................... 191576 33 13 .... Nut, Hex 1/4", Serrated......................... 210226 34 14 .... Manifold Assembly - Air/Gas................ 192309 35 15 .... Nipple, Close 1/8"................................ 191147-3 36 16.... Nipple, Close Stainless........................191772-1 37 17 .... Nipple, Tapped......................................86505-3 38 18 .... Nipple, 1-1/4" x 38 1/2"........................86505-28 40 19 .... Nipple, 1-1/4" x 28 3/