A.O. Smith DB/DW-720-1810 warranty DuraMax Pump Performance Requirements

Page 18

generator type boilers establish temperature rises. The deciding factor in choice of boiler temperature rise relates to the boiler inlet temperature. Boiler outlet, minus system temperature drop, is boiler inlet temperature. THE BOILER TEMPERATURE RISE SHOULD NOT RAISE THE OUTLET TEMPERATURE UP TO THE MAXIMUM 250°F (115°C) SETTING OF THE LIMIT CONTROL.

If inlet temperature (plus temperature rise) of any boiler on the group exceeds 240°F (115°C), that boiler and all downstream boilers will shut down (cycle on and off).

B. Commercial Boiler Replacements

Application of LINEAR-TEMP to a commercial boiler replacement with an old multiple pump installation is an excellent way to modernize the system. The A. O. Smith boiler(s) should be installed on a pipe loop with a separate circulating pump. Use table 7 to determine pipe sizes and operating ranges.

The following illustration shows how the system headers should be connected to pipe loop that is installed with the replacement

boiler(s). Make-up water connections, and accessories are not shown.

Supply and return headers of the old system should be connected to the boiler loop with a pair of tees set close together. The boiler loop pump and the boiler(s) should be wired to operate only when any of the system pumps are in operation. The number of zone pumps that may be in operation at any particular time will take their required flow rate out from the first tee in the boiler piping. This water will be circulated through the proper branches from the supply header to the zones calling for heat. The water will be brought back to the return header and then into the second tee in the boiler pipe loop. There will be no conflict between the boiler pump and the zone pumps when the two tees in the boiler loop are placed close together.

Normal use of flow control valves is required to prevent cross circulation of zones as with any multiple pump system.

Large systems with multiple boilers should include main water temperature controls (with or without outdoor reset) to sequence the boiler on and off, in relation to the load on the system.

TABLE 7, DuraMax Pump Performance Requirements

Model

Water

Temp Rise

Flow Rate

HdLoss*

Pipe Size

Taco Circulator

Category

F

C

GPM

LPM

ft

M

Sched. 40

Models

 

 

Soft

35

19.4

34

127

3.7

1.1

 

2"

#0012 (1/7 HP)

DW-720

Normal

25

13.9

47

178

6.2

1.9

 

2"

#120 (1/6 HP)

Hard

18

10.0

65

248

12.6

3.8

 

2"

#1935 (1/3 HP)

 

 

 

Hard

18

10.0

65

248

7.4

2.3

2

1/2"

#121 (1/4 HP)

 

Soft

35

19.4

39

149

5.9

1.8

 

2"

#0012 (1/7 HP)

DW-840

Normal

25

13.9

55

208

8.9

2.7

 

2"

#120 (1/6 HP)

Hard

18

10.0

76

289

15.1

4.6

 

2"

#1935 (1/3 HP)

 

 

 

Hard

18

10.0

76

289

10.2

3.1

2

1/2"

#1935 (1/3 HP)

 

Soft

35

19.4

45

170

6.6

2.0

 

2"

#0012 (1/7 HP)

DW-960

Normal

25

13.9

63

238

12.1

3.7

 

2"

#1935 (1/3 HP)

Normal

25

13.9

63

238

7.6

2.3

2

1/2"

#121 (1/4 HP)

 

 

Hard

18

10.0

87

330

12.9

3.9

2

1/2"

#1935 (1/2 HP)

 

Soft

35

19.4

51

193

7.0

2.1

 

2"

#120 (1/6 HP)

DW-1080

Normal

25

13.9

72

271

13.1

4.0

 

2"

#1935 (1/3 HP)

Normal

25

13.9

72

271

7.1

2.2

2

1/2"

#121 (1/4 HP)

 

 

Hard

19

10.6

94

356

11.3

3.4

2

1/2"

#1935 (1/2 HP)

 

Soft

35

19.4

57

217

4.7

1.4

2

1/2"

#120 (1/6 HP)

DW-1210

Normal

25

13.9

80

303

8.8

2.7

2

1/2"

#121 (1/4 HP)

 

Hard

19

10.6

105

399

13.4

4.1

2

1/2"

#1935 (1/2 HP)

 

Soft

35

19.4

64

242

6.0

1.8

2

1/2"

#121 (1/4 HP)

DW-1350

Normal

25

13.9

89

339

10.5

3.2

2

1/2"

#1935 (1/3 HP)

 

Hard

18

10.0

124

470

18.9

5.8

2

1/2"

#1935 (3/4 HP)

 

Soft

35

19.4

68

259

6.3

1.9

2

1/2"

#121 (1/4 HP)

DW-1480

Normal

25

13.9

96

362

12.7

3.9

2

1/2"

#1935 (1/2 HP)

Hard

18

10.0

133

503

20.5

6.2

2

1/2"

#1935 (3/4 HP)

 

 

Hard

18

10.0

133

503

12.2

3.7

 

3"

#133 (3/4 HP)

 

Soft

35

19.4

74

281

8.0

2.4

2

1/2"

#121 (1/4 HP)

DW-1610

Normal

25

13.9

104

394

13.6

4.1

2

1/2"

#1935 (1/2 HP)

Hard

20

11.1

130

492

20.7

6.3

2

1/2"

#1935 (3/4 HP)

 

 

Hard

20

11.1

130

492

12.4

3.8

 

3"

#133 (3/4 HP)

 

Soft

38

21.1

77

291

8.2

2.5

2

1/2"

#121 (1/4 HP)

DW-1810

Normal

28

15.6

104

395

13.8

4.2

2

1/2"

#1935 (1/2 HP)

Hard

22

12.2

133

503

20.9

6.4

2

1/2"

#1935 (3/4 HP)

 

 

Hard

22

12.2

133

503

12.6

3.8

 

3"

#133 (3/4 HP)

* - Head loss includes the loss through 40 feet (12 m) of pipe and normal fittings.

Pressure drop includes the loss through 40' (12 m) of pipe and normal fittings.

Water Category

Grain Hardness per Gal.

Soft

1 through 7.5

Normal

7.6 through 17

Hard

Over 17

Taco pumps shown. Equivalent Armstrong, Bell & Gossett or Grundfos acceptable. Always ensure adequate support for pump and piping.

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Contents Installation Operation Maintenance Limited Warranty TM Models DB/DW-720-1810Contents Replacement PartsForeword ROUGH-IN Dimensions Capacities Installation ClearancesLevelling Pressure Drop Manual Reset High Temperature Safety Limit Control FeaturesSafety Relief Valves Electronic Intermittent Pilot Ignition ControlThermal Balancer Automatic Reset High Temperature Limit ControlSafety Flow Switch Dual Stage Models only HIGH/LOW OperatorLocation Installation InstructionsRequired Ability AIR RequirementsVenting the Boiler Draft HoodVent Connection Connecting Boiler to a Common Vent GAS ConnectionsPurging Correct GASConventional Installations High Altitude InstallationsWiring Connections ExampleSystems Equipment Installation Circulating Pump Circulating Pump Must be Properly Sized for Your ApplicationConventional Space Heating Installation System InstallationTank Temperature Control 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 Internal Contaminants PrecautionsChecking and Adjusting the Input 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 Heat Exchanger Preventive Maintenance General MaintenanceVenting Maintenance Relief ValveMechanical Removal of Deposits Deliming SolventsRemoving Light Deposits of Scale 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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