Related Manuals for A.O. Smith On Demand 305 Series 100
Summary of Contents for A.O. Smith On Demand 305 Series 100
- Page 1 On-Demand Water Heater System Design Manual Design information for single and multiple unit installations for residential, commercial, recircula- tion and storage tank systems. PRINTED 0209 186965-001...
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Page 2: Table Of Contents
Table of Contents Certifications...3 Installing Gas Water Heater ...4-7 Water Quality and Scale ...8 Pump Sizing for Circulation...9 Tank Water Heaters in a Circulation Loop Additional Guidelines ...10 Pump Sizing for Storage Tank Applications Pressure Loss Curves ...12-13 Domestic Hot Water - Standard Installation 1 Water Heater (H-1)...14 2 Water Heaters (H-... -
Page 3: Certifications
ATI-305-N ATI-305-P ATO-305-N ATO-305-P ATI-505-N ATI-505-P ATO-505-N ATO-505-P ATI-705-N ATI-705-P ATO-705-N ATO-705-P *ATI-705A-N *ATI-705A-P *ATO-705A-N *ATO-705A-P The models listed in this manual have received the following certifications except where noted: Certified to applicable U.S. standards for appliances using gas or other petroleum fuel. Certified to applicable Canadian standards for appliances using gas or other petroleum fuel. - Page 4 Consumer Information The on-demand water heaters must be installed according to all local and state codes or, in the absence of local and state codes, the “National Fuel Gas Code”, ANSI Z223.1 (NFPA 54) - current edition. CSA American, Inc. 8501 East Pleasat Valley Road Cleveland, OH 44131 Check your phone listings for the local authorities having jurisdiction over your installation.
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Page 5: Site Location
In addition to using the lowest possible temperature setting that satisfies your hot water needs, a means such as a mixing valve, should be used at hot water taps used by these people or at the water heater. Mixing valves are available at plumbing supply or hardware stores. Follow manufacturer’s instructions for installation of the valves. - Page 6 For Storage Tank System Installation CAUTION - PROPERTY DAMAGE HAZARD The storage tank should be located in an area where leakage of the tank or connections will not result in damage to the area adjacent to the storage tank or to lower floors of the structure. Due to the normal corrosive action of the water, the tank will eventually leak after an extended period of time.
- Page 7 For Storage Tank System Installation Temperature and Pressure Relief Valve For protection against excessive pressures and temperatures, a temperature and pressure relief valve must be installed in the opening on the on-demand storage tank. This valve must be design certified by a nationally recognized testing laboratory that maintains periodic inspection of the production of listed equipment or materials as meeting the requirements for Releif Valves for Hot Water Supply Systems, ANSI Z21.22.
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Page 8: Water Quality And Scale
Water Quality and Scale A complete water analysis and an understanding of system requirements are needed to protect the on-demand water heaters and water heating systems from scale. Water analysis shows whether water is hard or soft. Hard water, unless treated, will cause scaling or liming of the heat exchanger. The rate of scaling increases with temperature and usage because calcium carbonate and other scaling compounds lose solubility (fall out of solution) at higher temperatures. -
Page 9: Pump Sizing For Circulation
Pump Sizing for Circulation 1. Use the chart below or one appropriate for your conditions to determine the heat loss in the length of the hot water supply and return piping. For example, 100 ft of 1-1/2 in bare copper tubing results in a heat loss of 5300 Btu/h. -
Page 10: Tank Water Heaters In A Circulation Loop
Tank Water Heaters in a Circulation Loop The following applies when using a tank water heater (gas or electric) to provide heat for a circulation loop. Drawing H-1-RP is an example. The heat output of the tank must be equal to or greater than the calculated circulation loop heat loss. (Reference page 5, Step 1 on calculating heat loss). -
Page 11: Pump Sizing For Storage Tank Applications
Pump Sizing for Storage Tank Application The following applies when using on-demand water heaters to recover a storage tank. Drawing H-1-TC is an example. On-Demand water heaters have a pressure loss which must be considered in the system design. Reference the pressure loss curve for the heater model being used to determine the pump size for the desired recovery rate. -
Page 12: Pressure Loss Curves
100/101 Series Pressure Loss Curves Pressure Loss (ft head) 305i 305e Pressure Loss (psi) - Page 13 Pressure Loss Curves 200/201 Series Pressure Loss (ft head) Pressure Loss (psi)
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Page 14: Domestic Hot Water - Standard Installation
3/4” Hot Water Supply Line 3/4" Ball Valve 3/4" Union NOTE: This drawing is not intended to describe a complete system and is not a replacement for a pro- fessional engineering drawing. It is intended only as a guide and does not imply compliance with local building code requirements. -
Page 15: Water Heaters (H- 2)
On-Demand Water Heater Primary Hot Water Supply Line 3/4" Ball Valve 3/4" Union NOTE: This drawing is not intended to describe a complete system and is not a replacement for a pro- fessional engineering drawing. It is intended only as a guide and does not imply compliance with local building code requirements. - Page 16 On-Demand Water Heater Primary Hot Water Supply Line 3/4" Ball Valve 3/4" Union NOTE: This drawing is not intended to describe a complete system and is not a replacement for a pro- fessional engineering drawing. It is intended only as a guide and does not imply compliance with local building code requirements.
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Page 17: Water Heaters (H- 4)
On-Demand On-Demand Water Heater Water Heater Sub 1 Primary Hot Water Supply Line 3/4" Ball Valve 3/4" Union NOTE: This drawing is not intended to describe a complete system and is not a replacement for a pro- fessional engineering drawing. It is intended only as a guide and does not imply compliance with local building code requirements. -
Page 18: Water Heaters (H- 5)
On-Demand On-Demand Water Heater Water Heater Primary Sub 1 Hot Water Supply Line 3/4" Ball Valve 3/4" Union NOTE: This drawing is not intended to describe a complete system and is not a replacement for a pro- fessional engineering drawing. It is intended only as a guide and does not imply compliance with local building code requirements. - Page 19 Demand Demand Water Water Heater Heater Primary Sub 1 Hot Water Supply Line 3/4" Ball Valve 3/4" Union NOTE: This drawing is not intended to describe a complete system and is not a replacement for a pro- fessional engineering drawing. It is intended only as a guide and does not imply compliance with local building code requirements.
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Page 20: Domestic Hot Water With Optional Freeze Protection
IMPORTANT! With electrical power supplied to a on-demand water heater, it will not freeze º in enviornments as cold as -30 F, when protected from direct wind exposure. In the event of a power failure at temperatures below freezing, the water heater should be drained of all water to prevent freezing damage. -
Page 21: Water Heaters (H-2- E)
IMPORTANT! With electrical power supplied to a on-demand water heater, it will not freeze in enviornments as cold as -30 F, when protected from direct wind exposure. In the event of a power failure at temperatures below freezing, the water heater should be drained of all water to prevent freezing damage. - Page 22 IMPORTANT! With electrical power supplied to a on-demand water heater, it will not freeze in enviornments as cold as -30 F, when protected from direct wind exposure. In the event of a power failure at temperatures below freezing, the water heater should be drained of all water to prevent freezing damage.
- Page 23 IMPORTANT! With electrical power supplied to a on-demand water heater, it will not freeze in enviornments as cold as -30 F, when protected from direct wind exposure. In the event of a power failure at temperatures below freezing, the water heater should be drained of all water to prevent freezing damage.
- Page 24 For this application: Pump should be controlled by an Aquastat, Timer or Combination Aquastat and Timer. Pump to be sized to maintain circulation loop temperature. The pump should be sized to overcome the pressure loss through the tank water heater, and supply and return plumbing in the circulation loop.
- Page 25 For this application: Pump should be controlled by an Aquastat, Timer or Combination Aquastat and Timer. Pump to be sized to maintain circulation loop temperature. The pump should be sized to overcome the pressure loss through the tank water heater, and supply and return plumbing in the circulation loop.
- Page 26 For this application: Pump should be controlled by an Aquastat, Timer or Combination Aquastat and Timer. Pump to be sized to maintain circulation loop temperature. The pump should be sized to overcome the pressure loss through the tank water heater, and supply and return plumbing in the circulation loop.
- Page 27 For this application: Pump should be controlled by an Aquastat, Timer or Combination Aquastat and Timer. Pump to be sized to maintain circulation loop temperature. A minimum of 3 GPM flow is recommended for the circulation system. The pump should be sized to overcome the pressure loss through the on demand water heater, optional storage tank, and supply and return plumbing in the circulation loop.
- Page 28 For this application: Pump should be controlled by an Aquastat, Timer or Combination Aquastat and Timer. Pump to be sized to maintain circulation loop temperature. The pump should be sized to overcome the pressure loss through the tank water heater, and supply and return plumbing in the circulation loop.
- Page 29 For this application: Pump should be controlled by an Aquastat, Timer or Combination Aquastat and Timer. Pump to be sized to maintain circulation loop temperature. The pump should be sized to overcome the pressure loss through the tank water heater, and supply and return plumbing in the circulation loop.
- Page 30 Building Hot Water Supply Line Storage Tank (No Burner or Heating Element) Submersible Aquastat (set @ 20°F below On- Demand Temperature Setting) 3/4" Ball Valve 3/4" Union NOTE: This drawing is not intended to describe a complete system and is not a replacement for a pro- fessional engineering drawing.
- Page 31 Building Hot Water Supply Line Storage Tank (No Burner or Heating Element) Submersible Aquastat (set @ 20°F below On- Demand Temperature Setting) Building Circulation Pump Domestic Hot Water - Backup Storage / Circulation 3/4" Ball Valve 3/4" Union NOTE: This drawing is not intended to describe a complete system and is not a replacement for a pro- fessional engineering drawing.
- Page 32 On-Demand Building Hot Water Water Heater Supply Line Storage Tank (No Burner or Heating Element) Submersible Aquastat (set @ 20°F below On-Demand Temperature Setting) 3/4" Ball Valve 3/4" Union NOTE: This drawing is not intended to describe a complete system and is not a replacement for a pro- fessional engineering drawing.
- Page 33 On-Demand Building Hot Water Water Heater Supply Line Storage Tank (No Burner or Heating Element) Submersible Aquastat (set @ 20°F below On- Demand Temperature Setting) Building Circulation Pump Building Hot Water Return Line Domestic Hot Water - Backup Storage / Circulation 3/4"...
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Page 34: Water Heaters (H-6- E)
On-Demand Building Hot Water Water Heater Supply Line Storage Tank (No Burner or Heating Element) Submersible Aquastat (set @ 20°F below On- Demand Temperature Setting) 3/4" Ball Valve 3/4" Union NOTE: This drawing is not intended to describe a complete system and is not a replacement for a pro- fessional engineering drawing. -
Page 35: Water Heaters (H-2- T)
Building Hot Water Supply Line Storage Tank (No Burner or Heating Element) Submersible Aquastat (set @ 20°F below On - Demand Temperature Setting) Building Hot Water Return Line Building Circulation Pump Domestic Hot Water - Backup Storage / Circulation 3/4" Ball Valve 3/4"... -
Page 36: Water Heaters (H-3- T)
Building Hot Water Supply Line On-Demand Water Heater Storage Tank (No Burner or Heating Element) Submersible Aquastat (set @ 20°F below On- Demand Temperature Setting) 3/4" Ball Valve 3/4" Union NOTE: This drawing is not intended to describe a complete system and is not a replacement for a pro- fessional engineering drawing. -
Page 37: Water Heaters (H-6- T)
Supply Line On-Demand Water Heater Expansion Tank Storage Tank (No Burner or Heating Element) Submersible Aquastat (set @ 20°F below On- Demand Temperature Setting) Building Hot Water Return Line Building Circulation Pump Domestic Hot Water - Backup Storage / Circulation 3/4"... -
Page 38: Scale Flush Procedure (Mp-01)
Flush Procedure 1. Disconnect electrical power to the water heater. and V4). 3. Connect pump outlet hose (H1) to the cold water line at service valve V2. 4. Connect drain hose (H3) to service valve V1. 5. Pour approximately 4 gallons of virgin, food grade, white vinegar or citric acid into pail. - Page 39 Notes...
- Page 40 • 500 Tennessee Waltz Parkway • Ashland, TN 37015 •...