A.O. Smith DB/DW-720-1810

DURA-MAX - MODULATED FIRING - SCHEMATIC DIAGRAM

DURA-MAX - MODULATED FIRING - UNITED STATES & CANADIAN MODELS

WITHOUT PUMP. 120 VOLT SYSTEM CONTROLLER

Contents

Main MODELS DB/DW-720-1810 NATURAL GAS-FIRED COMMERCIAL CROSS FLOW COPPER BOILERS FOR HYDRONIC HEATING AND HOT WA TER SUPPLY INSTALLATION OPERATION MAINTENANCE LIMITED WARRANTY FOREWORD CONTENTS REPLACEMENT PARTS ROUGH-IN DIMENSIONS/ CAPACITIES INSTALLATION CLEARANCES LEVELLING FEATURES IMPORTANT SAFETY RELIEF VALVES ELECTRONIC INTERMITTENT PILOT IGNITION CONTROL MANUAL RESET HIGH TEMPERATURE SAFETY LIMIT CONTROL AUTOMATIC RESET HIGH TEMPERATURE LIMIT CONTROL THERMAL BALANCER SAFETY FLOW SWITCH INSTALLATION INSTRUCTIONS REQUIRED ABILITY LOCATION CHEMICAL VAPOR CORROSION AIR REQUIREMENTS VENTING THE BOILER GAS CONNECTIONS PURGING HIGH ALTITUDE INSTALLATIONS WIRING CONNECTIONS SERVICING WIRING AND/OR CONTROL SYSTEMS EQUIPMENT INSTALLATION WATER SUPPLY LINE EXPANSION TANK VENT VALVES SYSTEM HEADERS CIRCULATING PUMP LOW WATER CUTOFF TANK TEMPERATURE CONTROL SYSTEM INSTALLATION GENERAL CONVENTIONAL SPACE HEATING INST ALLA TION INSTALLATION AS BOILER REPLACEMENT DB INSTALLATION Page BYPASS BALANCING LINEAR-TEMP SPACE HEATING APPLICATIONS LINEAR-TEMP SPACE HEATING INSTALLA TIONS TABLE 7, DuraMax Pump Performance Requirements Page Page Page Page Page Page Page Page HOT WATER SUPPL Y APPLICA TIONS Cer-Temp 80 Recovery Systems WATER LINE CONNECTIONS HARD WATER CONDITIONS ONE DURA-MAX (MODEL DW) COMMERCIAL BOILER WITH VERTICAL TANK ONE DURA-MAX (MODEL DW) COMMERCIAL BOILER WITH HORIZONTAL TANK CAUTION TO PREVENT CONDENSATION THE MINIMUM BOILER INLET TEMPERATURE IS 100F (38C) SEE TABLE 7 FOR GUIDE TO PIPE AND PUMP SIZING. TWO DURA-MAX (MODEL DW) HOT WATER SUPPLY BOILERS WITH VERTICAL TANK TWO DURA-MAX (MODEL DW) HOT WATER SUPPLY BOILERS WITH HORIZONTAL TANK MANIFOLDING OF MODEL TJV-120M & TJV-200M TANKS START-UP AND OPERATING INSTRUCTIONS TWO HORIZONTAL TANK INSTALLATION THREE HORIZONTAL TANK INSTALLATION LIGHTING AND OPERATING INSTRUCTIONS FOR YOUR SAFETY READ BEFORE OPERATING LIGHTING INSTRUCTIONS TO TURN OFF GAS TO APPLIANCE INTERNAL CONTAMINANTS PRECAUTIONS CHECKING AND ADJUSTING THE INPUT PILOT BURNER MAIN BURNER PRE-TROUBLE-SHOOTING TROUBLE-SHOOTING CHECKING HONEYWELL S8600H OR S8610M (NAT. GAS) INTERMITTENT IGNITION CONTROLS Page Page HEAT EXCHANGER PREVENTIVE MAINTENANCE DELIMING GENERAL MAINTENANCE RELIEF VALVE VENTING MAINTENANCE DELIMING SOLVENTS REMOVING LIGHT DEPOSITS OF SCALE MECHANICAL REMOVAL OF DEPOSITS REMOVAL OF AN EXISTING BOILER FROM A COMMON VENTING SYSTEM DURA-MAX LIMITED WARRANTY