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MODELS HW 300, 399, 420, 520, 610, 670
GAS-FIRED COMMERCIAL COPPER BOILERS FOR
HYDRONIC HEATING AND HOT WATER SUPPLY
UP-FLOW MODELS
• INSTALLATION • OPERATION • MAINTENANCE • LIMITED WARRANTY
• INDOOR ONLY
WARNING: If the information in this manual
is not followed exactly, a fire or explosion
may result causing property damage,
personal injury or death.
— Do not store or use gasoline or other
flammable vapors and liquids in the
vicinity of this or any other appliance.
— WHAT TO D
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SAFE INSTALLATION, USE AND SERVICE The proper installation, use and servicing of this water heater is extremely important to your safety and the safety of others. Many safety-related messages and instructions have been provided in this manual and on your own water heater to warn you and others of a potential injury hazard. Read and obey all safety messages and instructions throughout this manual. It is very important that the meaning of each safety message is understood by you and others who i
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GENERAL SAFETY 3
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TABLE OF CONTENTS SAFE INSTALLATION, USE AND SERVICE.......................................................................................................................................................................... 2 GENERAL SAFETY................................................................................................................................................................................................................ 3 TABLE OF CONTENTS ...............................
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DIMENSIONS AND CAPACITY DATA EXTRA OPENING FOR THERMOMETER AND RELIEF VALVE HW-520, 610 AND HW--670 TABLE 1 MODELS DIMENSIONS IN INCHES PROPANE NATURAL HW-300 HW-399 HW-420 HW-520 HW-610/670 HW-610/670 A Overall height 65 (1651) 57-1/8 (1451) 57-1/8 (1451) 68-5/16 (1735) 67 (1702) 64-3/4 (1645) B Height to Top of Jacket 43-1/4 (1099) 45-1/8 (1146) 45-1/8 (1146) 56-1/4 (1429) 56-1/4 (1429) 56-1/4 (1429) C Floor to Center Line Water Inlet 36 (914) 38-3/4 (984) 38-3/4 (984) 46 (1168) 46 (1168) 46 (
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TABLE 2, RECOVERY CAPACITIES Input °F 20 40 50 60 70 80 Model BTUH (kW) °C 11.1 22.2 27.7 33.3 38.8 44.4 GPH 1439 719 576 480 411 360 HW 300 300,000 (88) LPH 5448 2724 2179 1816 1556 1362 GPH 1914 957 765 638 547 478 HW 399 399,000 (117) LPH 7245 3623 2898 2415 2070 1811 GPH 2014 1007 806 671 576 504 HW 420 420,000 (123) LPH 7627 3813 3051 2542 2179 1907 GPH 2494 1247 998 831 713 624 HW 520 520,000 (152) LPH 9443 4721 3777 3148 2698 2361 GPH 2926 1463 1170 975 836 731 HW 610 610,000 (179) LPH 11
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INTRODUCTION This design complies with the current edition of the ANSI Z21.13 IF THE BOILER HAS BEEN EXPOSED TO FLOODING, IT low-pressure boiler standard. MUST BE REPLACED. Compliance under this standard implies that when the boiler LIQUEFIED PETROLEUM GAS MODELS underwent test, the gas manifold and control assembly prov ided on the boiler met safe lighting and other performance criteria. Boilers for propane or liquefied petroleum gas (LPG) are different from natural gas models. A natural ga
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HIGH ALTITUDE INSTALLATIONS Ratings specified by manufacturers for most boilers apply for elevations up to 2000 feet (600 m). For elevations above 2000 feet IN CANADA (600 m) ratings must be reduced by a rate of 4% for each 1000 feet (300 m) above sea level. Acceptance of these models for use at altitudes above 2000 feet (600 m) is based on field test of the individual installation by the Example: If a boiler is rated at 610,000 Btu/hr. at sea level, to operate provincial/state authority
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THERMAL BALANCER Figure 4 shows the internal wiring of the thermal balancer. The device may be tested after disconnecting the four leads from their respective terminals on the unit. 1. Apply a test light to the yellow and red leads. • The lamp should light as the contact in this circuit is normally closed when the resistor is cool. HIGH LIMIT SWITCH 2. Apply a light to the black and yellow leads. FIGURE 5. • The lamp should not light as the contact in this circuit is normally open when th
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To adjust the flow rate setting: CAUTION The switch is factory set at approximately the minimum flow rate, see 1. Remove the flow switch cover. Table 3 on page 9. It must not be set lower than the factory setting as this may result in the switch failing to return at 'no flow' condition. 2. For higher flow rate - turn the range adjusting screw clockwise. 4. Replace flow switch cover. Where units are installed in multiples, 3. For lower flow rate - turn the range adjusting screw each boiler
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Code, Section IV or CSA B51, as applicable. Select a relief valve with TANK TEMPERATURE CONTROL a discharge NOT less than the boiler input, and a pressure rating NOT exceeding the working pressure of any component in the system. The water temperature in the storage tank is controlled by the Tank Temperature Control. The sensing element is mounted inside the A. O. Smith supplies a 125 psi relief valve for hot water supply systems hot water storage tank. and 50 psi relief valve for space heati
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THERMOMETERS Time to Produce 2nd & 3rd Water Temperature Degree Burns on Adult Skin Thermometers should be obtained and field installed as shown in the installation diagrams. OVER: 170°F (77°C) Nearly Instantaneous 160°F (71°C) About 1/2 second Thermometers are installed in the system as a means 150°F (65°C) About 1-1/2 seconds of detecting a possible liming condition in the boiler. 140°F (60°C) Less than 5 seconds An increase of 5°F (3°C) over the normal temperature 130°F (54°C) About 3
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PERMIT OPERATION OF GAS APPLIANCES IF INSTALLED If the confined space is within a building of tight construction, 18 INCHES OR MORE ABOVE THE FLOOR. THIS MAY air for combustion, ventilation, and draft hood dilution must be REDUCE THE RISK IF LOCATION IN SUCH AN AREA CANNOT obtained from outdoors. When directly communicating with the BE AVOIDED. outdoors or communicating with the outdoors through vertical ducts, two permanent openings, located in the above manner, shall be provided. Each
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INSTALLATION CLEARANCES Sufficient area should be provided at the front and rear of the unit for proper servicing. Clearances of 24 inches (609.4mm) in the rear and 48 inches (1,219mm) in the front are required by code. These boilers are approved for installation on combustible flooring In a utility room installation, the door shall be wide enough to allow in an alcove with minimum clearance to combustibles of: the boiler to enter or to permit the replacement of another appliance such
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Building materials must not come in contact with combustion Vent connectors serving appliances vented by natural draft shall not products from stack or chimney, due to the degradating properties be connected into any portion of mechanical draft systems operating of flue products. under positive pressure. Flue products must have a minimum clearance of 4 feet (1.22m) 3. CONNECTING BOILER TO A COMMON VENT horizontally from, and in no case above or below, unless a 4-foot (1.22m) horizontal distan
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4. MULTIPLE VENT TABLE 1. Turn off the electrical power (main manual gas shutoff and pilot valves, if applicable). Table 5 on page 17 has been compiled to show the material sizes in a Type B doublewall combined vent system. Refer to Allow boiler parts and vent to cool before disassembly. CAN/CSA B149 .1 (current edition), or the ASHRAE 1983 Equipment Volume for further information. 2. Remove the boiler draft diverter and vent pipe running to the chimney. • Check parts and chimney for obst
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TABLE 5, COMBINED VENT SIZING TABLES MODEL HW-610 BOILER MODEL HW-300 BOILER Input: 610,000 Btuh Draft Hood Outlet 12" Input: 300,000 Btuh Draft Hood Outlet 8" Required Connector or Smoke Pipe Diameter Required Connector or Smoke Pipe Diameter Total Vent Height (Measured in Feet Above Draft Hood) Total Vent Height (Measured in Feet Above Draft Hood) Connector Connector 10 15 20 30 40 50 60 80 100 10 15 20 30 40 50 60 80 100 Rise in Feet Rise in Feet Connector Diameter (in Inches) Connector Dia
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SYSTEM INSTALLATIONS 1. CONVENTIONAL INSTALLATIONS All modern hydronic type boilers are exceptionally fast heating units. The low water volumes in relation to firing rates require special attention to water flow rates for smooth, efficient operation. These considerations for the A. O. Smith copper heat exchanger boilers are covered below. 0 0 Conventional 20 F (10 C) drop in systems for a fully loaded boiler will maintain the following approximate flow rates: MODELS GPM (LPM) HW-300 23 (87
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NO. SUGGESTED ITEMS FOR INSTALLATION Short pipe nipple and pair of boiler loop tees in piping 1 between system supply and return. One set per each group of boilers. 2 Boiler pipe loop. See piping sizing data. 3 Boiler circulator. See pump sizing data. 4 Thermometer. 5 Theraltimeter. 6 Plug cock to control flow rate. Safety flow switches. For interlock with other systems or 7 instead of low water cutoff. 8 Relief valve. With one -300, -399 or -420 item 9 is - sensing element of remote control
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5. VENT VALVES If the boiler is connected to chilled water piping or its heating coils are exposed to refrigerated air, the boiler piping system must be It is recommended that automatic, loose key or screwdriver type equipped with flow valves or other automatic means to prevent gravity vent valves be installed at each convector or radiator. circulation through the boiler during the cooling cycle. 6. MANIFOLD HEADERS 8. CIRCULATING PUMP Split systems with individual supply and return lines fr
