A.O. Smith DB/DW-720-1810 warranty Venting the Boiler, Draft Hood, Vent Connection

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If the confined space is within a building of tight construction, air for combustion, ventilation, and draft hood dilution must be obtained from outdoors. When directly communicating with the outdoors or communicating with the outdoors through vertical ducts, two permanent openings, located in the aforementioned manner, shall be provided. Each opening shall have a free area of not less than one square inch per 4000 Btu/hr (551 mm2 per kw) of the total input of all appliances in the enclosure. If horizontal ducts are used, each opening shall have a free area of not less than one square inch per 2000 Btu/hr (1101 mm2 per kw) of the total input of all appliances in the enclosure.

(B) CANADIAN INSTALLATIONS

Ventilation of the space occupied by the boiler(s) shall be provided by an opening for ventilation air at the highest practical point communicating with outdoors. The total cross- sectional area shall be at least 10% of the area of the combustion air opening but in no case shall the cross-sectional area be less than 10 square inches (6500 mm²).

In addition to the above, there shall be permanent air supply opening(s) having a cross-sectional area of not less than 1 square inch per 7,000 BTUH (315 mm²/kw) up to and including 1,000,000 BTUH plus 1 square inch per 14,000 BTU (158 mm2/kw) in excess of 1,000,000 BTUH. This opening(s) shall be located at, or ducted to, a point neither more than 18" (450 mm) nor less than 6 inches (150 mm) above the floor level.

Where power vented equipment is used in the same room as the boiler, sufficient air openings must be supplied.

UNDERSIZED OPENINGS MAY RESULT IN INSUFFICIENT AIR FOR COMBUSTION.

Where an exhaust fan is installed in the same room with a boiler, sufficient openings for air must be provided in the walls.

UNDERSIZED OPENINGS WILL CAUSE AIR TO BE DRAWN INTO THE ROOM THROUGH THE CHIMNEY, CAUSING POOR COMBUSTION. SOOTING MAY RESULT WITH AN INCREASED RISK OF ASPHYXIATION.

VENTING THE BOILER

WARNING

THE INSTRUCTIONS IN THIS SECTION ON VENTING THE BOILER MUST BE FOLLOWED TO AVOID CHOKED COMBUSTION OR RECIRCULATION OF FLUE GASES. SUCH CONDITIONS CAUSE SOOTING OR RISKS OF FIRE AND ASPHYXIATION.

SINGLE WALL OR TYPE B VENTING MAY BE USED WITH THESE BOILERS. ALL LOCAL UTILITY, STATE/ PROVINCIAL, REGULATIONS ON VENTING MUST BE FOLLOWED.

VENT SIZING, INSTALLATION AND TERMINATION SHALL BE IN ACCORDANCE WITH PART 7, VENTING OF EQUIPMENT, OF THE NATIONAL FUEL GAS CODE, ANSI Z223.1, OR SECTION 7, VENTING SYSTEMS AND AIR SUPPLY FOR APPLIANCES, OF THE CAN/CSA B149, INSTALLATION CODES, OR APPLICABLE PROVISIONS OF THE LOCAL BUILDING CODES.

1.DRAFT HOOD

The integral draft hood, louvers or cabinetry must not be altered. Provision must be made if the boiler is installed in confined space or a small boiler room to accommodate draft hood spillage and avoid risks described above. The upper air opening called for in the AIR REQUIREMENTS section of this manual is for this purpose.

2.VENT CONNECTION

The minimum distance from adjacent public walkways, adjacent buildings, openable windows and building openings shall not be less than those values specified in the National Fuel Gas Code, ANSI Z223.1 and/or CAN/CSA B149.1-00, Installation Codes:

Stack or chimney must be a minimum height of 12" (305 mm) above the annual snow fall to prevent blockage.

Building materials must not come in contact with combustion products from stack or chimney, due to the degrading properties of flue products.

Materials may be protected from flue products by use of metal or copper sheeting.

Flue products must have a minimum clearance of 4 feet (1.22 m) horizontally from, and in no case above or below, unless a 4-foot (1.22 m) horizontal distance is maintained, from electric meters, gas meters, regulators and relief equipment.

The Canadian B149.1-00, Installation Code specifies a 6 foot horizontal vent terminal clearance to gas and electric meters and relief devices (this clearance is specified as 4 feet in the U.S. under the National Fuel Gas Code, ANSI/Z223.1). Therefore instruction provision 1.34.1-b19(d), which specifies compliance with the 4 foot clearance, as applies in the U.S. only, and the B149.1-00 Installation Code applies in Canada.

Vent connections must be made to an adequate stack or chimney and shall be in accordance with Part 7, Venting of Equipment, of the National Fuel Gas Code, ANSI Z223.1, or Section 7, Venting Systems and Air Supply for Appliances, of the CAN/CSA-B149.1- 00, Installation Codes, or applicable provisions of the local building codes. Size and install proper size vent pipe. Do not reduce pipe size to less than that of the draft hood outlet unless permitted by local code.

Horizontal runs of vent pipe shall be securely supported by adequately placed (approximately every 4 feet [1.2 m]), noncombustible hangers suitable for the weight and design of the materials employed to prevent sagging and to maintain a minimum upward slope of 1/4" per foot (21mm/m) from the boiler to the vent terminals. Dampers or other obstructions must not be installed in the vent. Be sure that the vent connector does not extend beyond the inside wall of the chimney.

Where a continuous or intermittent back draft is found to exist the cause must be determined and corrected. A special vent cap may be required. If the back draft cannot be corrected by the normal methods or if a suitable draft cannot be obtained, a blower type flue gas exhauster may be employed to ensure proper venting and correct combustion (where permitted by local code). Contact your A. O. Smith dealer for power vent instructions.

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Contents Installation Operation Maintenance Limited Warranty TM Models DB/DW-720-1810Foreword ContentsReplacement Parts Levelling ROUGH-IN Dimensions CapacitiesInstallation Clearances Pressure Drop Features Safety Relief ValvesManual Reset High Temperature Safety Limit Control Electronic Intermittent Pilot Ignition ControlAutomatic Reset High Temperature Limit Control Safety Flow SwitchThermal Balancer Dual Stage Models only HIGH/LOW OperatorInstallation Instructions Required AbilityLocation AIR RequirementsVent Connection Venting the BoilerDraft Hood Connecting Boiler to a Common Vent GAS ConnectionsPurging Correct GASHigh Altitude Installations Wiring ConnectionsConventional Installations ExampleSystems Equipment Installation Circulating Pump Circulating Pump Must be Properly Sized for Your ApplicationSystem Installation Tank Temperature ControlConventional Space Heating Installation LOW Water CutoffDB Installation Installation AS Boiler ReplacementPage LINEAR-TEMP Space Heating Installations LINEAR-TEMP Space Heating ApplicationsDuraMax Pump Performance Requirements Safety Flow Switch Thermometer Pressure GaugeONE Boiler LINEAR-TEMP System Page Page Page Page Page Page Hard Water Conditions ONE DURA-MAX Model DW Commercial Boiler with Vertical TankONE DURA-MAX Model DW Commercial Boiler with Horizontal Tank NPT NPT Manifolding of Model TJV-120M & TJV-200M Tanks START-UP and Operating Instructions For Your Safety Read Before Operating Precautions Checking and Adjusting the InputInternal Contaminants Pilot BurnerPRE-TROUBLE-SHOOTING TROUBLE-SHOOTINGNo Spark AT Pilot Burner YESSpark AT Pilot Burner but Pilot will not Light Pilot Burner Lights but Main Burner does not Light General Maintenance Venting MaintenanceHeat Exchanger Preventive Maintenance Relief ValveDeliming Solvents Removing Light Deposits of ScaleMechanical Removal of Deposits Removal of AN Existing Boiler from a Common Venting SystemDURA-MAX Limited Warranty Page Page Replacement Parts

DB/DW-720-1810 specifications

A.O. Smith has a longstanding reputation for quality and innovation in the water heater industry, and the DB/DW-720-1810 model exemplifies these values. This particular water heater is designed to provide reliable hot water, making it suitable for both residential and commercial applications. Its impressive features and cutting-edge technologies set it apart from conventional models.

One of the primary features of the A.O. Smith DB/DW-720-1810 is its energy efficiency. It operates using advanced insulation technologies, minimizing heat loss and promoting energy savings. This model is designed with a high-efficiency burner that substantially reduces energy consumption while maintaining optimal performance. It also complies with industry standards for energy efficiency, ensuring that users can enjoy lower utility bills without sacrificing comfort.

The DB/DW-720-1810 is equipped with a robust tank designed to hold an ample supply of hot water. With a capacity of 75 gallons, it is ideal for households with high demand, such as multi-bathroom residences or commercial establishments. This large capacity ensures that hot water is readily available for various activities, from bathing to cleaning.

User control is another notable characteristic of the A.O. Smith DB/DW-720-1810. The model features an intuitive digital display that allows users to monitor and set water temperatures easily. This interface not only enhances usability but also promotes safety, preventing scalding by allowing users to adjust the temperature to their preference.

Durability is a key consideration in the DB/DW-720-1810’s design. It is built with high-quality materials and features a corrosion-resistant tank, ensuring longevity even in challenging water conditions. This resilience is further supplemented by A.O. Smith's advanced anode rod technology, which helps battle corrosion and extends the lifespan of the water heater.

Lastly, maintenance is simplified with this model. A.O. Smith has designed the water heater for easy access to serviceable parts, making routine maintenance more convenient and less time-consuming. Coupled with warranty options that provide peace of mind, the DB/DW-720-1810 stands out as a dependable choice.

In summary, the A.O. Smith DB/DW-720-1810 combines energy efficiency, significant capacity, user-friendly controls, durability, and low maintenance needs, making it an exceptional option for those needing a reliable hot water solution.
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