— WHAT TO DO IF YOU SMELL GAS: • Do not try to light any appliance. • Do not touch any electrical switch; do not use any phone in your building. • Immediately call your gas supplier from a neighbor’s phone. Follow the gas supplier’s instructions. • If you cannot reach your gas supplier, call the fire department. — Installation and service must be performed by a qualified installer, service agency or the gas supplier. CAUTION TEXT PRINTED OR OUTLINED IN RED CONTAINS INFORMATION RELATIVE TO YOUR SAFETY. PLEASE READ THOROUGHLY BEFORE INSTALLING AND USING THIS APPLIANCE. USER'S INFORMATION MANUAL GB/GW-300, 400, 500, 650, 750 SERIES 400, 401, 402, 403, 404, 405, 2-STAGE UNITS WARNING Should overheating occur or the gas supply fail to shut off, do not turn off or disconnect the electrical supply to the pump. Instead, shut off the gas supply at a location external to the appliance. WARNING Do not use this boiler if any part has been under water. Immediately call a qualified service technician to inspect the boiler and to replace any part of the control system and any gas control which has been under water. INDEX PAGE LIGHTING INSTRUCTIONS ....................................... 2-3 MAINTENANCE .......................................................... 3-4 OPERATING SEQUENCE, EMC5000 ......................... 8-14 CONNECTION DIAGRAM ............................................ 13 EMC5000 INSTRUCTIONS ...................................... 14-18 WARRANTY................................................................. 19 A DIVISION OF A. O. SMITH CORPORATION MC BEE, SC., RENTON, WA., STRATFORD-ONTARIO, VELDHOVEN-THE NETHERLANDS PLEASE KEEP THESE INSTRUCTIONS ADJACENT TO BOILER AND NOTIFY OWNER TO KEEP FOR FUTURE REFERENCE. PRINTED IN U.S.A. 0306 PART NO. 212132-001 THE UNIT SHOULD NOT BE INSTALLED DIRECTLY ON A FLAMMABLE ITEMS, PRESSURIZED CONTAINERS OR ANY OTHER POTENTIAL FIRE HAZARDOUS ARTICLES MUST CARPETED FLOOR. A FIRE HAZARD MAY RESULT. Instead, NEVER BE PLACED ON OR ADJACENT TOTHE BOILER. OPEN the boiler must be installed on the A. O. Smith Combustible CONTAINERS OF FLAMMABLE MATERIAL SHOULD NOT BE Floor Kit Base or concrete blocks extending beyond the full width STORED OR USED IN THE SAME ROOM WITH THE BOILER. and depth of the boiler by at least 3 (76.2mm) inches. If the boiler is installed in a carpeted alcove, the entire floor must be Light the unit in accordance with the instructions on the lightingcovered with concrete blocks, or use the A. O. Smith Combustible and operating label attached to the boiler. These instructions Floor Kit Base. are repeated on the following two pages. Lighting Instructions for the G(B/W) 300 through 750 models 2 LIGHTING INSTRUCTIONS These models have an automatic hot surface ignition system mounted on the combustion chamber panel inside the front jacket. This hot surface igniter ignites the main burner gas whenever the system control calls for heat. Before proceeding with operation of the unit, make sure the boiler and system are filled with water and all air is expelled from the boiler, radiator tank(s) and piping. WARNING THE MAIN MANUAL GAS SHUT-OFF VALVE MUST HAVE BEEN CLOSED FOR AT LEAST FIVE (5) MINUTES BEFORE LIGHTING. This waiting period is an important safety step. Its purpose is to permit gas that might have accumulated in the combustion chamber to clear. IF YOU DETECT GAS AT THE END OF THE PERIOD DO NOT PROCEED WITH LIGHTING. RECOGNIZE THAT GAS ODOR, EVEN IF IT SEEMS WEAK, MAY INDICATE PRESENCE OF ACCUMULATED GAS SOMEPLACE IN THE AREA WITH A RISK OF FIRE OR EXPLOSION. WARNING THERE IS A RISK IN USING FUEL BURNING APPLIANCES SUCH AS GAS WATER BOILERS IN ROOMS, GARAGES OR OTHER AREAS WHERE GASOLINE AND OTHER FLAMMABLE LIQUIDS ARE USED OR STORED, OR ENGINE-DRIVEN EQUIPMENT OR VEHICLES ARE STORED, OPERATED OR REPAIRED. FLAMMABLE VAPORS ARE HEAVYAND TRAVEL ALONG THE FLOOR AND MAY BE IGNITED BY THE BOILER'S MAIN BURNER FLAMES CAUSING FIRE OR EXPLOSION. Some local codes permit operation of gas appliances if installed 18 inches or more above the floor. This may reduce the risk if location in such an area cannot be avoided. TEMPERATURE REGULATION DANGER HOT WATER TEMPERATURES REQUIRED FOR AUTOMATIC DISHWASHER AND LAUNDRY USE CAN CAUSE SCALD BURNS RESULTING IN SERIOUS PERSONAL INJURY AND/ OR DEATH. THE TEMPERATURE AT WHICH INJURY OCCURS VARIES WITH THE PERSON'S AGE AND TIME OF EXPOSURE. THE SLOWER RESPONSE TIME OF CHILDREN, AGED OR DISABLED PERSONS INCREASES THE HAZARDS TO THEM. NEVER ALLOW SMALL CHILDREN TO USE A HOT WATER TAP, OR TO DRAW THEIR OWN BATH WATER. NEVER LEAVE A CHILD OR DISABLED PERSON UNATTENDED IN A BATHTUB OR SHOWER. THE WATER HEATER SHOULD BE LOCATED IN AN AREA WHERE THE GENERAL PUBLIC DOES NOT HAVE ACCESS TO SET TEMPERATURES. It is recommended that lower water temperatures be used to avoid the risk of scalding. It is further recommended, in all cases, that the water temperature be set for the lowest temperature which satisfies the user's ...