A.O. Smith HW-300, HW-520, HWB-610, HWB-420, HW-420 User Manual

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MODELS HW/HWB 300, 399, 420, 520, 610, 670

GAS-FIRED COMMERCIAL COPPER BOILERS FOR

HYDRONIC HEA TING AND HOT W A TER SUPPL Y

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 DO IF YOU SMELL GAS

• Do not try to light any appliance.

• Do not touch any electrical switch; do not use any phone in your building.

• Immediately call your gas supplier

TEXT PRINTED OR OUTLINED IN RED CONT AINS INFORMATION RELATIVE TO YOUR SAFETY. PLEASE READ THOROUGHLY BEFORE USING APPLIANCE.

CAUTION

from a neighbor's phone. Follow the gas supplier's instructions.

• If you cannot reach your gas supplier, call the fire department.

— Installation and service must be

performed by a qualified installer, service agency or the gas supplier.

PLACE THESE INSTRUCTIONS ADJACENT TO BOILER AND

NOTIFY OWNER TO KEEP FOR FUTURE REFERENCE

PRINTED IN U.S.A. 0905 SUPERSEDES PART NO'S, 210288-000 REV. 01 & 192356-000

A DIVISION OF A.O. SMITH CORPORATION

MC BEE, SC SEATTLE, W A

STRATFORD, ONT ARIO

VELDHOVEN, THE NETHERLANDS

www.hotwater.com

PART NO. 211683-000 REV.02

ROUGH-IN DIMENSIONS

HW/HWB-610

AND HW-670

NA TURAL GAS ONL Y

EXTRA OPENING FOR THERMOMETER AND RELIEF VALVE HW/HWB-520, 610 AND HW--670

TABLE 1 MODELS

Prop. Nat.

DIMENSIONS IN INCHES

HWB/ HWB/ HWB/ HWB/ HWB/ HWB/

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 (1168) D Diameter of jacket 25-1/4 (641) 27 (686) 27 (686) 27 (686) 27 (686) 27 (686)

E Floor to center line water outlet 12 (305) 12 (305) 12 (305) 12 (305) 12 (305) 12 (305)

F Draft diverter outlet diameter 8 (203) 10 (254) 10 (254) 10 (254) 12 (305) 12 (305) G Floor to center line gas inlet 16-1/2 (419) 16-3/4 (425) 16-3/4 (425) 18 (457) 18 (457) 18 (457) H Overall depth 29-5/8 (753) 31-1/2 (800) 31-1/2 (800) 36-1/2 (927) 36-1/2 (927) 36-1/2 (927)

J Support height 9 (229) 9 (229) 9 (229) 9(229) 9 (229) 9 (229) K Width of control string (approx.) 14 (356) 14 (356) 14 (356) 11(279) 11 (279) 11 (279) L Pipe size of water inlet (NPT) 1-1/4 1-1/2 1-1/2 2 2 2

M Pipe size of water outlet(NPT) 1-1/4 1-1/2 1-1/2 2 2 2

N Pipe size of gas inlet (NPT) 3/4 1 1 1 1 1 P Control string plus 1/2 jacket dia. (approx.) 26-5/8 (676) 27-1/2(699) 27-1/2 (699) 24-1/2 (622) 24-1/2 (622) 24-1/2 (622) Q Water outlet to jacket 1 (25) 1 (25) 1 (25) 3-1/2 (89) 3-1/2 (89) 3-1/2 (89) R Water inlet casting to center line of jacket 10-1/8 (257) 11-1/4 (286) 11-1/4 (286) 12 (305) 12 (305) 12 (305) S Horizontal length between water inlet and outlet 5-3/8 (137) 5-1/2 (140) 5-1/2 (140) 5-3/4 (146) 5-3/4 (146) 5-3/4 (146) T Control string from jacket 5 (127) 5 (127) 5 (127) 7 (178) 7 (178) 7 (178)

Approx. shipping weight lbs. (Kilograms) 240 (109) 291 (132) 291 (132) 361 (164) 361 (164) 361 (164)

NOTE: All dimensions in inches (millimeters) except pipe size which is NPT.

TABLE 2, SPECIFICATIONS - CANADIAN MODELS ONLY

Maximum

Maximum I.A.S. Maximum Max. Heat Transfer Max. Heat Transfer

Model Type of Gas BTUH(KW) BTUH(KW) Heat Loss Load Surface Area (Sq. Ft.) Surface Area (Sq. Ft.)

HWB-300 Natural & Propane 300,000 (88) 247,200 (72) 210,120 (62) 1,410 (.41) 1,051 (.31) HWB-399 Natural & Propane 399,000 (116) 322,790 (95) 274,371 (80) 1,829 (.54) 1,372 (.40) HWB-420 Natural & Propane 420,000 (123) 344,400 (101) 292,740 (86) 1.952 (57) 1,464 (.43) HWB-520 Natural & Propane 520,000 (152) 429,000 (126) 364,650 (107) 2,431 (.71) 1,823 (.53) HWB-610 Natural 610,000 (179) 502,600 (147) 427,210 (125) 2,848 (.83) 2,136 (.61) HWB-610 Propane 610,000 (179) 488,000 (143) 414,800 (121) 2,765 (.81) 2,074 (.61)

Ratings shown are for current modern heating system design. Where A.O. Smith boilers are connected to heavy, cast iron radiator systems or where unusual pick-up or large size piping conditions exist, reduce ratings by 10%.

NOTE: To compensate for the effects of high altitude areas above 2000 feet, the input, output and heating load ratings should be reduced approximately 4% for each 1000 feet above sea level.

TABLE 3, RECOVERY CAPACITIES - CANADIAN MODELS ONLY

Model (Btu/Hr.) Rise (F) 20 30 40 50 60 70 80 90 100 110 120 130 140

HW-300 300,000 LPH 5,505 3,670 2,753 2,202 1,835 1,573 1,376 1,223 1,001 1,001 918 847 786 HW-399 399,000 LPH 7,322 4,882 3,661 2,929 2,441 2,092 1,831 1,627 1,464 1,331 1,220 1,127 1,046 HW-420 420,000 LPH 7,708 5,138 3,854 3,083 2,569 2,202 1,927 1,713 1,542 1,401 1,285 1,186 1,101 HW-520 520,000 LPH 9,543 6,362 4,771 3,817 3,181 2,727 2,386 2,121 1,909 1,735 1,590 1,468 1,363 HW-610 610,000 LPH 11,194 7,463 5,597 4,478 3,731 3,198 2,799 2,488 2,239 2,035 1,866 1,722 1,599

Input Temp. (C) 11 17 22 26 33 39 44 50 56 61 67 72 78

GPH 1,455 970 727 582 485 416 364 323 291 264 242 224 208 GPH 1,935 1,290 967 774 645 553 484 430 387 352 322 298 276 GPH 2,036 1,358 1,018 815 679 582 509 453 407 370 339 313 291 GPH 2,521 1,681 1,261 1,008 840 720 630 560 504 458 420 388 360 GPH 2,958 1,972 1,479 1,183 986 845 739 657 592 538 493 455 423

FOREWORD

CAUTION

TEXT PRINTED OR OUTLINED IN RED CONT AINS INFORMATION RELA TIVE TO YOUR SAFETY. PLEASE READ THOROUGHLY BEFORE USING APPLIANCE.

Detailed installation diagrams are in this manual. These diagrams will serve to provide the installer with a reference for the materials and method of piping suggested. IT IS NECESSARY THA T ALL W ATER AND GAS PIPING AND THE ELECTRICAL WIRING BE INST ALLED AND CONNECTED AS SHOWN IN THE DIAGRAMS.

CHECK THE DIAGRAMS THOROUGHL Y BEFORE STARTING INSTALLA TION TO A VOID POSSIBLE ERRORS AND TO MINIMIZE TIME AND MATERIALS COST .

This design complies with the latest edition of ANSI Z21.13. CSA 4.9 low-pressure boiler .

Particular attention should be given to the installation of thermometers at

TABLE OF CONTENTS

PAGE

ROUGH-IN DIMENSIONS ................................................................... 2-3

FOREWORD ...................................................................................... 4

INSTALLA TION INSTRUCTIONS ........................................................ 4

Required Ability .......................................................................... 4

Installation As Boiler Replacement ............................................. 4

Location ...................................................................................... 5

Air Requirements........................................................................ 5-6

Chemical Vapor Corrosion ......................................................... 6

Installation Clearances ............................................................... 6

Levelling...................................................................................... 6

System Connections .................................................................. 6-9

Gas Connections ........................................................................ 9-11

Gas Pressure Regulators .......................................................... 11-12

Venting The Boiler - Standard Venting....................................... 12-14

Venting Maintenance - Standard Venting .................................. 15

Venting Sidewall (Optional) Power Vent System ...................... 15

Venting System .......................................................................... 15

Safety Relief Valves .................................................................. 15-16

Wiring Connections .................................................................... 16-31

Water Line Connections ............................................................. 32

Hard Water ................................................................................. 32

T ank Temperature Control .......................................................... 32-33

Low Water Cutoff ...................................................................... 33

Thermometers ............................................................................ 33

Drain Valve (Not Supplied)......................................................... 33

Closed Water System ................................................................ 33

Piping Diagrams .......................................................................... 34-45

the locations indicated in the diagrams as these are necessary for checking the operation of the boiler.

MAKE SURE THE GAS ON WHICH THE BOILER WILL OPERA TE IS THE SAME AS THA T SPECIFIED ON THE UNIT RATING PLA TE.

The boiler installation must conform to these instructions and the requirements of the local authority having jurisdiction.

Where required by authority having jurisdiction, the installation must conform to the Standard for Controls and Safety Devices for Automatically Fired

Boilers, ANSI/ASME CSD-1.

In absence of local code requirements, the boiler installation must conform

National Fuel Gas Code, ANSI Z223.1 and/or CAN/CSA B-149.1-00

to the Installation Codes.

These manuals can be purchased from the CSA International, 8501 East Pleasant Valley Road, Cleveland, OH 44131 or 178 Rexdale Boulevard, T oronto, Ontario Canada M9W1R3.

PAGE

STA RT-UP AND OPERATING INSTRUCTIONS .................................. 45

Filling And Venting ...................................................................... 46

Pilot and Main Burner ................................................................. 46

Lighting Instructions ................................................................... 47-48

Pilot and Main Burner (Continued) ............................................. 49-51

Electronic Intermittent Pilot Ignition Control ................................. 51

Normal Operating Sequence With Honeywell S-8600H or

S-8610M Intermittent Ignition Control (I.I.D.) ............................... 52

High Altitude Installations ........................................................... 52

Thermal Balancer ....................................................................... 52

Coil High Limit Control (Protector Switch).................................. 52-53

Pressure Reducing Valve .......................................................... 53

Safety Flow Switch ................................................................... 53-54

Safety Relief Valve Maintenance ............................................... 54

Replacement Parts ..................................................................... 54

REMOVAL OF EXISTING BOILER FROM A COMMON

VENTING SYSTEM............................................................................ 54

GENERAL MAINTENANCE ................................................................ 55

Relief Valve ................................................................................ 55

CLEANING AND FLUSHING INSTRUCTIONS .................................... 55

Internal Contaminants ................................................................. 55

Hot Water Supply Boilers - Preventive Maintenance ................ 55

Deliming ....................................................................................... 55-56

Deliming Solvents ....................................................................... 56

Heavy Lime Deposits ................................................................. 56

Removing Silicate ....................................................................... 56

PRE-TROUBLE-SHOOTING ............................................................... 57

TROUBLE-SHOOTING....................................................................... 57-61

LIMITED WARRANTY........................................................................ 62

INST ALLA TION INSTRUCTIONS

REQUIRED ABILITY

INST ALLATION OR SERVICE OF THIS BOILER REQUIRES ABILITY EQUIVALENT TO THAT OF A LICENSED TRADESMAN IN THE FIELD INVOLVED. PLUMBING, AIR SUPPLY, VENTING, GAS SUPPL Y AND ELECTRICAL WORK ARE REQUIRED.

INST ALLA TION AS BOILER REPLACEMENT

Installation as boiler replacement on an old system with large water volume may experience condensation within the boiler on cold starts. This condensing of water vapor in the combustion area can be prevented if a portion of the system water flow is diverted past the boiler to cause an increase in boiler temperature rise.

With old systems where water temperature can be expected to drop appreciably due to long standby periods, a bypass pipe of at least 1" size with a balancing cock should be installed between the boiler inlet and outlet. When the system first starts, the valve should be slowly opened until the condensing ceases. This adjustment remains at a permanent setting to establish required temperature rise across the boiler.

The equipment shall be installed in accordance with those installation regulations in force in the local area where the installation is to be made. These shall be carefully followed in all cases. Authorities having jurisdiction shall be consulted before installations are made.

LOCATION

When installing the boiler, consideration must be given to proper location. Location selected should be as close to the stack or chimney as practicable with adequate air supply and as centralized with the piping system as possible. This location should also be such that the gas ignition system components are protected from water (dripping, spraying, etc.) during appliance operation and service (circulator replacement, control replacement, etc.).

THE BOILER MUST NOT BE INST ALLED ON CARPETING. THE BOILER SHOULD NOT BE LOCATED IN AN AREA WHERE IT

WILL BE SUBJECT TO FREEZING.

LOCATE IT NEAR A FLOOR DRAIN. THE BOILER SHOULD BE LOCA TED IN AN AREA WHERE LEAKAGE FROM THE BOILER OR CONNECTIONS WILL NOT RESULT IN DAMAGE TO THE ADJACENT AREA OR TO LOWER FLOORS OF THE STRUCTURE.

WHEN SUCH LOCATIONS CANNOT BE AVOIDED, A SUITABLE DRAIN P AN SHOULD BE INSTALLED UNDER THE BOILER. Such pans should be fabricated with sides at least 60mm (2-1/2") deep, with length and width at least 50mm (2") greater than the diameter of the boiler and must be piped to an adequate drain. The pan must not restrict combustion air flow.

WARNING FOR SAFE OPERATION PROVIDE ADEQUATE AIR FOR COMBUSTION AND VENTILATION. AN INSUFFICIENT SUPPLY OF AIR WILL CAUSE RECIRCULATION OF COMBUSTION PRODUCTS RESUL TING IN AIR CONTAMINATION THA T MA Y BE HAZARDOUS TO LIFE. SUCH A CONDITION OFTEN WILL RESUL T IN A YELLOW , LUMINOUS BURNER FLAME, CAUSING CARBONING OR SOOTING OF THE COMBUSTION CHAMBER, BURNERS AND FLUE TUBES AND CREATES A RISK OF ASPHYXIATION.

UNCONFINED SPACE

In buildings of conventional frame, brick or stone construction, unconfined spaces may provide adequate air for combustion, and draft hood dilution.

If the unconfined space is within a building of tight construction (buildings using the following construction: weather stripping, heavy insulation, caulking, vapor barrier, etc.) air for combustion, ventilation, and draft hood dilution must be obtained from outdoors or spaces freely communicating with the outdoors. The installation instructions for confined spaces in tightly constructed buildings must be followed to ensure adequate air supply.

CONFINED SPACE

WARNING

KEEPING BOILER AREA CLEAR AND FREE FROM COMBUSTIBLE MA TERIALS, GASOLINE AND OTHER FLAMMABLE V APORS AND LIQUIDS.

WARNING THERE IS A RISK IN USING FUEL BURNING APPLIANCES SUCH AS BOILERS IN ROOMS OR AREAS WHERE GASOLINE, OTHER FLAMMABLE LIQUIDS OR ENGINE DRIVEN EQUIPMENT OR VEHICLES ARE STORED, OPERATED OR REPAIRED. FLAMMABLE VAPORS ARE HEAVY AND TRAVEL ALONG THE FLOOR AND MA Y BE IGNITED BY THE IGNITER OR MAIN BURNER FLAMES CAUSING FIRE OR EXPLOSION. SOME LOCAL CODES PERMIT OPERATION OF GAS APPLIANCES IF INSTALLED 18 INCHES OR MORE ABOVE THE FLOOR. THIS MA Y REDUCE THE RISK IF LOCATION IN SUCH AN AREA CANNOT BE A VOIDED.

WARNING FLAMMABLE ITEMS, PRESSURIZED CONTAINERS OR ANY OTHER POTENTIAL FIRE HAZARDOUS ARTICLES MUST NEVER BE PLACED ON OR ADJACENT TO THE BOILER. OPEN CONTAINERS OF FLAMMABLE MA TERIAL MUST NOT BE STORED OR USED IN THE SAME ROOM WITH THE BOILER.

A hot water boiler installed above radiation level or as required by the authority having jurisdiction, must be provided with a low water cutoff device at the time of boiler installation.

AIR REQUIREMENTS

Provisions for combustion and ventilation air in accordance with section 5.3, Air for Combustion and Ventilation, of the National Fuel Gas Code, ANSI Z223.1, or sections 7.2, 7.3, or 7.4 of CAN/CSA B149.1-00, Installation Codes, or applicable provisions of the local building codes.

Provisions for vent, bleed and gas relief lines (when applicable).

(a) U. S. INSTALLATIONS

When drawing combustion and dilution air from inside a conventionally constructed building to a confined space, such a space shall be provided with two permanent openings, ONE WITHIN 12 INCHES OF THE ENCLOSURE TOP AND ONE WITHIN 12 INCHES OF THE ENCLOSURE BOTTOM. Each opening shall have a free area of at least one square inch per 1000 Btuh of the total input of all appliances in the enclosure, but not less than 100 square inches.

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 above manner, shall be provided. Each opening shall have a free area of not less than one square inch per 4000 Btuh 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 Btuh of the total input of all appliances in the enclosure.

(b) CANADIAN INSTALLA TIONS

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 mm

)

In additional 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 (310 mm 1,000,000 BTUH

plus 1 square inch per 14,000 BTU in excess of

/KW) up to and including

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.

Keep appliance area free of combustible or flammable liquids. Do not obstruct the flow of combustion or ventilating air.

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 ASPHYXIA TION.

CHEMICAL V APOR CORROSION

WARNING CORROSION OF THE FLUEWAYS AND VENT SYSTEM MAY OCCUR IF AIR FOR COMBUSTION CONTAINS CERTAIN CHEMICAL V APORS WHICH BREAK DOWN INTO ACIDS A T HIGH TEMPERATURE. SUCH CORROSION MA Y RESUL T IN F AILURE AND RISK OF ASPHYXIA TION.

Water boiler corrosion and component failure can be caused by the heating and breakdown of airborne chemical vapors. Spray can propellants, cleaning solvents, refrigerator and air conditioning refrigerants, swimming pool chemicals, calcium and sodium chloride, waxes, and process chemicals are typical compounds which are corrosive. These materials are corrosive at very low concentration levels with little or no odor to reveal their presence. Products of this sort must not be stored near the boiler. Also, air which is brought in contact with the water boiler should not contain any of these chemicals. If necessary, uncontaminated air should be obtained from remote or outside sources.

INST ALLA TION CLEARANCES

These boilers are approved for installation on combustible flooring in an alcove with minimum clearance to combustibles of:

TABLE 4

HWB/HW HWB/HW HWB/HW HWB/HW HWB/HW

300 399 420 52 0 610 & 670

TOP 28" (71 1.2) 32" (812.8) 24" (609.6) 24" (609.6) 24" (609.6)

SIDES 6" (152.4) 6" (152.4) 24" (609.6) 24" (609.6) 24" (609.6)

REAR 6" (152.4) 6" (152.4) 24" (609.6) 24" (609.6) 24" (609.6) VENT 6" (152.4) 6" (152.4) 6" (152.4) 6" (152.4) 6" (152.4)

Two inch (50.8mm) clearance is allowable from combustible construction for hot water pipes.

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. In a utility room installation, the door shall be wide enough to allow the boiler to enter or to permit the replacement of another appliance such as a water heater.

LEVELLING

Each unit should be checked after installation to be certain that it is level.

If the unit is not level, insert metal shims under the legs of the unit to correct this condition.

SYSTEM CONNECTIONS

The system installation must conform to these instructions and to the requirements of the local code authority having jurisdiction. Good practice requires that all heavy piping be supported.

A TYPICAL BOILER INST ALLATION

FIGURE 1

1. CONVENTIONAL INST ALLA TIONS 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.

Conventional 10

C (200F) drop in systems for a fully loaded boiler

will maintain the following approximate flow rates:

U.S. CANADIAN

MODELS MODELS LPM GPM

HW-300 HWB-300 87 23 HW-399 HWB-399 114 30 HW-420 HWB-420 132 35 HW-520 HWB-520 148 39 HW-670 HWB-610 175 46

Figure 1 shows a typical installation of the boiler with pipe sizing and circulator selected by the installer to provide adequate water flow whenever the boiler is firing.

In a system with several large zones of which any might be smaller than approximately 1/3 of the system should include a hydronic balancer as shown in fig. 1. The balancer connects between the system supply and the return line before the circulator inlet. Adjustment of the balancing cock should permit adequate boiler flow rate when only the smallest zone is in operation.

Attention should be given to balancing inputs and water flow rates where wide variations of system flow rates can occur.

The recommended minimum flow rates that will result in approximately 30

C (500F) temperature rise across the boiler are

as follows:

ONE BOILER INSTALLED

INDEPENDENT OF THE PRIMARY SYSTEM

FIGURE 2

Total heating requirements for the building can be supplied by a series of boiler loops all connecting to a common pipe joining the system supply and return mains. The supply and return branches of each boiler loop must join the common pipe only a short nipple length apart. The different sets of branches should be installed reasonably close together, but not necessarily to the short nipple length as required for the supply and return of each set. These branches may be made with tees or with welded connections.

The installer is reminded that the total boiler flow rates need not match the system flow rate.

U.S. CANADIAN

MODELS MODELS LPM GPM

HW-300 HWB-300 34 9 HW-399 HWB-399 45 12 HW-420 HWB-420 53 14 HW-520 HWB-520 61 16 HW-610 HWB-610 69 18 HW-670

76 20

If system flow rate is unknown, or if zoning creates extreme variations in flow rates, the boiler should be installed as shown in fig. 2 for A. O. Smith

LINEAR-TEMP INSTALLA TIONS

LINEAR-TEMP installations.

A. New Installations

A. O. Smith

LINEAR-TEMP systems have been designed to provide efficient, trouble-free operation of the boiler sizes covered in this manual with any of the following conditions:

a. Unknown system flow rate b. Varying flow rate as with zoned systems c. Multiple boiler installations

Figure 2 shows piping and accessory arrangement for a boiler pumped independent of the primary system mains. Pipe sizing and boiler loop pump selection data are shown in Table 5 for several different temperature rises across the boilers.

TABLE 5

PUMP AND PIPE SIZING DA T A

(PIPING FROM TEES IN MAIN TO BOILER BRANCHES)

Quantity and Model Temp. *Pump Pipe

U. S Canadian Rise°C (°F) G.P.M. Size Size

10 (20) 23 1-1/2"PR 2"

HW-300 1 HWB-300 15 (30) 15 1 50 1-1/2"

15 (30) 15 125 1-1/4" 20 (40) 11 10 0 1" 10 (20) 30 60-13 2"

HW-399 1 HWB-399 15 (30) 20 1-1/2"HV 1-1/2"

20 (40) 15 150 1-1/2" 20 (40) 15 125 1-1/4" 10 (20) 32 60-13 2"

HW-420 1 HWB-420 15 (30) 21 1-1/2"HV 1-1/2"

20 (40) 16 150 1-1/2" 20 (40) 16 125 1-1/4" 10 (20) 39 2-1/2" 2-1/2"

HW-520 1 HWB-520 10 (20) 26 1-1/2"HV 2"

17 (35) 23 1-1/2"HV 1-1/2" 20 (40) 20 150 1-1/2" 10 (20) 51 60-13 3"

HW-670 1 HWB-610 15 (30) 34 2-1/2" 2-1/2"

17 (35) 29 2" 2" 20 (40) 25 1-1/2"HV 1-1/2"

NOTE: Pipe loop sizes and pump selections based on

50 equivalent feet of pipe and fittings.

*All pump sizes listed are B & G model numbers.

NO . SUGGESTED ITEMS FOR INST ALLA TION

1 Short pipe nipple and pair of boiler loop tees in piping

between system supply and return. One set per each

group of boilers 2 Boiler pipe loop. See piping sizing data above. 3 Boiler circulator. See pump sizing data above. 4 Thermometer. 5 Theraltimeter. 6 Plug cock to control flow rate. 7 Safety flow switches. For interlock with other systems or

instead of low water cutoff. 8 Relief valve. 9 With one -300, -399 or -420 item 9 is - sensing

element of remote control.

With a group of -300's, -399's or -420's, item 9 is - for

1st. boiler, the sensing element as above. For additional

boilers, install a 2nd. limit control if required by local codes.

With any -520, -610 or 670 boilers, install 2nd. limit control

here if required by local code.

BOILER INLET - OUTLET SIZES

10 HWB-300 - 1-1/4", HWB-399 - 1-1/2", HWB-420-1-1/2",

HWB-520 & HWB-610 - 2". Canadian Models

10 HW-300 - 1-1/4", HW-399 - 1-1/2", HW-420-1-1/2",

HW-520 & HW-670 - 2". U.S. Models

MINIMUM BRANCH SIZES TO BOILERS

1 1 HWB-300 - 1-1/4" HWB-520, 610 (Single boiler

HWB-399 - 1-1/2" per pump) 2"

HWB-420 - 1-1/2" Canadian Models

1 1 HW-300 - 1-1/4" HW-520, 670 (Single boiler

HW-399 - 1-1/2" per pump) 2"

HW-420 - 1-1/2" U.S. Models

12 Flow control valve. Required only if flow rate of system

primary is excessive for size of boiler branch tees or if

chilled water main is above boilers.

13 System supply temperature thermometer. 14 Boiler headers for three (3) boilers can be larger than pipe loop,

if desired, to aid in balancing.

SCHEMATIC OF THE LINEAR-TEMP® SYSTEM

FIGURE 3

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. Flow control is not required on boiler circuit.

The system flow rate is selected to give the desired system temperature drop - depending on the design criteria.

The boiler generator flow rates, on the other hand, should be selected to give the temperature rise through the generator that is both economical and offers the best generator efficiency.

The boiler temperature rise is normally between 10

(20

F and 400F). The system temperature that will be introduced

C and 200C

to the boiler (inlet temperature) plus the selected boiler temperature rise selected from PUMP AND PIPE SIZING DAT A should not exceed the high limit control setting of 115

C (2400F).

There should be a relation of the minimum system load to the size boiler selected as the first firing or base boiler. This will stabilize operation during minimum load periods.

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 selected from PUMP AND PIPE SIZING DA T A T ABLE.

Figure 3 shows a line drawing of how the system headers should be connected to the pipe loop installed with the replacement boiler(s). Make-up water connections and accessories are not shown.

Attention should be given to balancing gas inputs and water flow rates. Large systems with multiple boilers should include main water temperature control (with or without outdoor reset) to stage the boilers on and off in relation to the load on the system.

3. WA TER SUPPL Y LINE These boilers can be used ONLY in a forced circulation hot water

heating system. Since most forced circulation systems will be of the closed type, install the water supply line as shown on piping diagrams, fig. 1 or 2.

Fast filling of large pipe, old radiator installations and pressure purging of series loop systems (where high pressures are not available) requires bypassing of the pressure reducing valve. Generally, pressure purging is not possible with a well pump system. High point air venting is essential.

If the system is of the open type, a pressure reducing valve will not be required as the water supply to the system will be controlled by a manually operated valve. An overhead surge tank is required.

4. EXPANSION T ANK

CAUTION

A closed system will exist if a check valve (without bypass), pressure reducing valve (without bypass), or a water meter (without bypass) is installed in the cold water line between the water heater and street main (or well).

Excessive pressure may develop causing premature tank failure or intermittent relief valve operation.

This is not a warranty failure. An expansion tank or a similar device may be required in the inlet supply line between the appliance and the meter or valve to compensate for the thermal expansion of water under supply pressure, see figure 1.

If the boiler is connected to chilled water piping or its heating coils are exposed to refrigerated air, the boiler piping system must be equipped with flow valves or other automatic means to prevent gravity circulation through the boiler during the cooling cycle.

8. CIRCULATING PUMP

An air separator as shown in the piping diagrams is recommended especially for modern commercial hydronic systems.

5. VENT V ALVES

It is recommended that automatic, loose key or screwdriver type vent valves be installed at each convector or radiator.

6. MANIFOLD HEADERS Split systems with individual supply and return lines from the boiler

room should normally have this piping connected to supply and return manifold headers near the boiler. To achieve good water distribution with maximum pressure drop for several circuits, manifolds of at least 2-1/2" (64mm) diameter are suggested on HWB/HW-399, HWB/HW-420, HWB/HW-520, HWB/HW-610 and HW-670 units. HWB/HW-300 units should have 1-1/2" (38mm) diameter manifolds.

The circuits should be spaced on the header at a minimum of 3" (76mm) center to center. Install a balancing cock in each return line.

Manifold headers are recommended for split systems with or without zone valves and also those installations with zone circulators. If the system is to be split at remote points, good practice requires special attention be given to main pipe sizing to allow balancing of water flow.

The boiler piping system of a hot water boiler connected to heating coils located in air handling units where they may be exposed to refrigerated air circulation must be equipped with flow control valves or other automatic means to prevent gravity circulation of the boiler water during the cooling cycle.

CONSTANT CIRCULATING PUMP OPERATION OF THE BOILER VOIDS THE W ARRANTY. Constant water flow through the unit will “wash” away the copper’s natural protective coating. This is called velocity erosion. This erosion is not as great a problem when intermittent circulating operation is used per the recommended installation procedure. Constant circulation of water through the building’s system main is permissible as long as the water does not constantly flow through the boiler. Only all bronze or stainless steel circulators are to be used with the unit when it is installed in HOT WA TER SUPPL Y SYSTEMS .

A TYPICAL CIRCULA TING PUMP

FIGURE 5

Although each circulator that requires oiling is oiled and operated by the manufacturer, IT MUST BE OILED AGAIN BEFORE OPERATED. Oil the three oil cup s (2 on the motor, 1 on the pump) as instructed on the oil tube supplied with the unit, fig 5.

Thereafter, during the heating season, lubricate the three oil cups at least once every four months. Combination heating-cooling systems should be lubricated every four months year ‘round.

Use 2 or 3 teaspoonsful in bearing oil cups, fig. 5, and 10 or 12 drops in the motor oil cups. Use No. 20 non-detergent motor oil.

7. COOLING PIPING

When the boiler is used in conjunction with a refrigeration system it must be installed so that the chilled medium is piped in parallel with the boiler with appropriate valves to prevent the chilled medium from entering the boiler, fig. 4.

Water temperature in the heating system must be reduced to less

than 100

F (38°C) before cooling system is started, or damage to

the chiller unit may occur.

SCHEMATIC SHOWING PROPER PIPING ISOLA TION

OF THE BOILER FROM THE CHILLER

FIGURE 4

Follow the same oiling procedure if a replacement circulator is installed into the system.

GAS CONNECTIONS

WARNING

THIS BOILER IS NOT INTENDED TO OPERA TE AT GAS SUPPLY PRESSURE OTHER THAN SHOWN ON THE RATING PLATE. EXPOSURE TO HIGHER GAS SUPPL Y PRESSURE MA Y CAUSE DAMAGE TO GAS VA LVES WHICH CAN RESULT IN FIRE OR EXPLOSION. IF OVERPRESSURE HAS OCCURRED SUCH AS THROUGH IMPROPER TESTING OF GAS LINES OR EMERGENCY MALFUNCTION OF THE SUPPL Y SYSTEM, THE GAS VA LVES MUST BE CHECKED FOR SAFE OPERATION. MAKE SURE THAT THE OUTSIDE VENTS ON THE SUPPLY REGULATORS AND THE SAFETY VENT V ALVES ARE PROTECTED AGAINST BLOCKAGE. THESE ARE PARTS OF THE GAS SUPPLY SYSTEM, NOT THE BOILER. VENT BLOCKAGE MA Y OCCUR DURING ICE BUILD-UP OR SNOW STORMS.

WHEN LOCAL CODES REQUIRE A MAIN MANUAL SHUTOFF V ALVE OUTSIDE THE BOILER JACKET , A SUIT ABLE MAIN MANUAL SHUTOFF VALVE MUST BE INSTALLED IN A LOCATION COMPL YING WITH THOSE CODES.

IT IS IMPORT ANT TO GUARD AGAINST GAS V ALVE FOULING FROM CONT AMINANTS IN THE GAS WA YS. SUCH FOULING MA Y CAUSE IMPROPER OPERATION, FIRE OR EXPLOSION.

IF COPPER SUPPLY LINES ARE USED THEY MUST BE CERTIFIED FOR GAS SERVICE.

BEFORE ATTACHING THE GAS LINE BE SURE THAT ALL GAS PIPE IS CLEAN ON THE INSIDE.

TO TRAP ANY DIRT OR FOREIGN MATERIAL IN THE GAS SUPPL Y LINE, A DIRT LEG (SOMETIMES CALLED DRIP LEG or sediment trap) MUST BE INCORPORA TED IN THE PIPING, SEE FIG . 1. The dirt leg must be readily accessible and not subject to freezing conditions. INSTALL IN ACCORDANCE WITH RECOMMENDA TIONS OF SERVING GAS SUPPLIERS. (Refer to National Fuel Gas Code, ANSI Z223.1 and/or CAN/CSA-B 149.1-00 Installation Codes.

To prevent damage, care must be taken not to apply too much torque when attaching gas supply pipe to gas valve gas inlet.

Fittings and unions in the gas line must be metal to metal type. Apply joint compounds (pipe dope) sparingly and only to the male

threads of pipe joints. Do not apply compound to the first two threads. Use compounds resistant to the action of liquefied petroleum gases.

THE BOILER AND ITS GAS CONNECTIONS MUST BE LEAK TESTED BEFORE PLACING THE BOILER IN OPERATION. Use soap and water solution or other material acceptable for the purpose in locating gas leaks. DO NOT USE MA TCHES, CANDLES, FLAME OR OTHER SOURCES OF IGNITION FOR THIS PURPOSE.

DISCONNECT THE BOILER AND ITS MAIN MANUAL GAS SHUTOFF VALVE FROM THE GAS SUPPLY PIPING SYSTEM DURING ANY PRESSURE TESTING OF THE GAS SUPPLY SYSTEM OVER 1/2 PSIG (3.5kPa).. THE GAS SUPPL Y LINE MUST BE CAPPED WHEN NOT CONNECTED TO THE BOILER.

2A.SIZING GAS SUPPLY LINE (For single boiler installations and

for installations of multiples of two or three of same size boilers).

Use table 6, or CAN/CSA B149.1-00 (latest recent edition) to size iron pipe or equivalent gas supply line. Table 6 is based on a pressure drop of 0.3 inches of water and a specific gravity of 0.60 approximately that of natural gas. (LP gas has an S.G. of about

1.53). If the service pressure is five inches water column or less, use one pipe size larger than specified in table 6 in order to minimize pressure drop in the line.

TABLE 6

MAXIMUM CAPACITY OF PIPE IN CUBIC FEET OF GAS PER

HOUR (BASED UPON A PRESSURE DROP OF 0.3 INCH WA TER

COLUMN AND 0.6 SPECIFIC GRA VITY GAS)

Length Meters

From Gas (Nominal Iron Pipe Size (Inches)

Meter 1/2 3/4 1 1 1/4 1 1/2 2 2 1/2 3 4

3 (10) 132 278 520 1,050 1,600 3,050 4,800 8,500 17,500 6 (20) 92 190 350 730 1,100 2,100 3,300 5,900 12,000

9 (30) 73 152 285 590 890 1,650 2,700 4,700 9,700 12 (40) 63 130 245 500 760 1,450 2,300 4,100 8,300 15 (50) 56 115 215 440 670 1,270 2,000 3,600 7,400

18 ((60) 50 105 195 400 610 1,150 1,850 3,250 6,800

21 (70) 46 96 180 370 560 1,050 1,700 3,000 6,200 24 (80) 43 90 170 350 530 990 1,600 2,800 5,800 27 (90) 40 84 160 320 490 930 1,500 2,600 5,400

30 (100) 38 79 150 305 460 870 1,400 2,500 5,100 38 (125) 34 72 130 275 410 780 1,250 2,200 4,500 45 (150) 31 64 120 250 380 710 1,130 2,000 4,100 53 (175) 28 59 110 225 350 650 1,050 1,850 3,800 60 (200) 26 55 100 210 320 610 980 1,700 3,500

*The heating value of Natural Gas is approximately 1,050 Btu/Ft.3. Propane (LP) Gas has a heating value of approximately 2,500 Btu/Ft3. 1 cu. meter=35.31 cu. feet.

Where it is necessary to use more than the average number of pipe fittings i.e. elbows, tees, and valves in gas supply line, use a pipe larger than specified to compensate for increased pressure drop.

THE BOILER MUST BE ISOLATED FROM THE GAS SUPPLY PIPING SYSTEM BY CLOSING ITS MAIN MANUAL GAS SHUTOFF VA LVE DURING ANY PRESSURE TESTING OF THE GAS SUPPL Y PIPING SYSTEM AT TEST PRESSURES EQUAL TO OR LESS THAN 1/2 PSIG (3.5kPa).

PURGING

Gas line purging is required with new piping or systems in which air has entered.

CAUTION

PURGING SHOULD BE PERFORMED BY PERSONS EXPERIENCED IN THIS TYPE GAS SERVICE TO A VOID RISK OF FIRE OR EXPLOSION. PURGE DISCHARGE MUST NOT ENTER CONFINED AREAS OR SP ACES WHERE IGNITION CAN OCCUR. THE AREA MUST BE WELL VENTILA TED AND ALL SOURCES OF IGNITION MUST BE INACTIV ATED OR REMOVED.

1. CORRECT GAS Make sure the gas on which the boiler will operate is the same as

that specified on the boiler rating plate. Do not install the boiler if equipped for a different type gas — consult your supplier.

2B. SIZING GAS SUPPLY LINE (For multiples of over three boilers

of same size or for multiple installations of two or more mixed sizes).

Capacities in cubic feet per hour of 0.60 specific gravity gas for different sizes and lengths are shown in table 6. No additional allowance is necessary for an ordinary number of fittings.

Applications of the gravity factor converts the figures given in table 6 to capacities with another gas of different specific gravity. Such application is accomplished by multiplying the capacities given in table 6 by the multipliers shown in table 7.

To determine the size of each section of gas piping in a system within the range of table 6 proceed as follows:

• Determine the gas demand of each appliance to be attached

to the piping system. When table 6 is to be used to select the piping size, calculate the gas demand in terms of cubic feet per hour for each piping system outlet. The gas demand for an appliance can be found by dividing its heat input rate by the gas’s heating value.

• Obtain or determine the length of piping from the gas meter or service regulator to the appliance(s).

1010

• In table 6, select the row showing the distance to the most remote outlet or the next longer distance if the table does not give the exact length. This is the only distance used in determining the size of any section of gas piping. If the gravity factor is to be applied, the values in the selected row of table 6 are multiplied by the appropriate multiplier from table 7.

• Total the gas demands of all appliances on the piping system. Enter table 6, on the left hand side, at the row equal to or just exceeding the distance to the most remote outlet. Select the pipe size in the row with a capacity equal to or just exceeding the total gas demand. This is the required main gas supply line size leading away from the gas meter or regulator. To determine the pipe size required for each branch outlet leading away from the main supply line, determine the gas demand for that outlet. Enter table 6 on the same row, and select the branch pipe size for a capacity equal to or just exceeding the demand at that outlet. The main line can be resized for a lesser capacity after each branch outlet, since the gas demand is reduced. Total the gas demands of all remaining appliances branching off downstream on the main gas line. Re-enter table 6 in the same row and select the appropriate pipe size with adequate capacity. Repeat the branch sizing and main line re-sizing for any remaining appliances in the system.

TABLE 7

MULTIPLIERS TO BE USED WITH T ABLE 6 WHEN APPL YING

THE GRA VITY FACTOR T O OTHER THAN .60 SPECIFIC GRAVITY

Specific Specific

Gravity Multiplier Gravity Multiplier

.35 1.31 1.00 .78 .40 1.23 1.10 .74 .45 1.16 1.20 .71 .50 1.10 1.30 .68 .55 1.04 1.40 .66

*.60 (Nat.) 1.00 *1.50 (Prop.) .63

.65 .96 1.60 .61 .70 .93 1.70 .59 .75 .90 1.80 .58 .80 .87 1.90 .56 .85 .84 *2.00 (Butane) .5 5

.90 .82 2.10 .54 *Use these correction factors if exact specific gravity of the gas is not known.

GAS PRESSURE REGULA TORS

The gas pressure regulator is included in the combination gas valve, fig. 6, and is set to operate on the gas specified on the boiler model and rating plate.

Periodically check main burner, fig. 41, and pilot flame, fig. 42, for proper operation. This should be checked every six months.

EXAMPLE Job Condition: Determining the required gas pipe size for a system composed of

two HWB/HW-420 boilers and two HWB/HW-610 boilers to be installed as a multiple group, 50 lineal feet from meter. Gas to be used has a .60 specific gravity and heating value of 1,000 Btu per cubic foot.

Solution: 2 HWB/HW-420 Boilers = 840,000 Btuh

2 HWB/HW-610 Boilers = 1,220,000 Btuh Total Btuh Input = 2,060,000 Btuh

Do not subject the gas valve to inlet gas pressures of more than 14" W.C. (1/2 P.S.I.). If higher gas pressures are encountered, a service regulator is necessary.

TABLE 8

CORRECT MANIFOLD PRESSURE FOR FULL

BOILER INPUT (IN INCHES OF WA TER COLUMN)

Model Rated Manifold Pressure

Number Input Natural Propane

HWB/HW-300 300,000 3.5 10.0 HWB/HW-399 399,000 3.2 9.5 HWB/HW-420 420,000 3.5 10.0 HWB/HW-520 520,000 3.5 10.0 HWB/HW-610 610,000 3.5 10.0

HW-670 Nat. 660,000 3.5

HW-670 Prop. 670,000 10.0

Adjustment, if required, is performed as follows:

1. Set primary system temperature control dial (thermostat) at

lowest setting so that boiler will not call for heat.

2. Attach a pressure gauge to the tapping in the control string

elbow.

3. Reset primary system temperature control dial (thermostat)

to highest setting. Main burner will now ignite.

Total Btuh Input = 2,060,000 Btuh = 2,060 cf/h Btu per Cubic Foot of Gas 1,000 With a cubic foot per hour demand of 2,060 and with 50 lineal feet

of gas supply line, table 6 shows a pipe size of 3" (76mm) is required.

NOTE: For other than .60 specific gravity, apply multiplier factor

as shown in table 7.

4. With main burner firing, adjust pressure, if necessary, by turning

pressure regulator adjusting screw with a screwdriver.

• Clockwise to increase pressure.

• Counterclockwise to decrease pressure.

5. Set primary system temperature control dial (thermostat) to

lowest setting.

6. Remove pressure gauge and replace sealing plug.

1111

7. Set primary system temperature control dial (thermostat) to desired setting.

WARNING

DO NOT INCREASE GAS PRESSURE ABOVE THAT SPECIFIED ON THE RATING PLATE, AS OVERFIRING WILL RESULT IN DAMAGE TO THE BOILER, AS WELL AS INCREASED RISK OF FIRE, SOOTING AND ASPHYXIA TION.

If gas pressure regulator cannot be adjusted to correct pressure with sufficient gas pressure at the valve, replace with new gas valve.

VENTING THE BOILER - STANDARD VENTING

Vent connectors serving appliances vented by natural draft shall not be connected into any portion of mechanical draft systems operating under positive pressure.

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" (305mm) 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 degradating properties of flue products.

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 ASPHYXIA TION.

TYPE B VENTING MAY BE USED WITH THESE BOILERS. ALL LOCAL UTILITY REGULATIONS ON VENTING SHOULD BE FOLLOWED.

ROBERTSHA W® 7000 DERHC

HWB/HW-300, 399,-420, -520, -610, -670 NATURAL GAS WITH I.I.D.

HW-300, -399, -420, -520, -670 LP GAS WITH I.I.D. U.S. ONLY

Flue products must have a minimum clearance of 4 feet (1.22m) horizontally from, and in no case above or below, unless a 4-foot (1.22m) 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 134.1-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.

1. DRAFT HOOD The draft hood furnished with this boiler must be installed without

alteration. 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 Size and install proper size vent pipe. Do not reduce pipe size to

less than that of the draft hood outlet. Horizontal runs of vent pipe shall be securely supported by

adequately placed (approximately every 4 feet or 1 meter), noncombustible hangers and/or slip joints suitable for the weight and design of the materials employed to prevent sagging and to maintain a minimum upward slope of 1/4" (21mm/m) per foot from the boiler to the vent terminals, fig. 7. Dampers or other obstructions must not be installed in the vent. Be sure that the vent pipe does not extend beyond the inside wall of the chimney.

HWB/HW-300, 399,-420, -520, -610 SINGLE STAGE

ROBERTSHAW® 7000 ERHC (LP)

STANDING PILOT, CANADIAN ONLY

FIGURE 6

For boilers for connection to gas vents or chimneys, 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 B149.1-00, Installation Codes, or applicable provisions of the local building codes.

1212

VENT PIPE INST ALLA TION

FIGURE 7

® Robertshaw is a registered trademark of Fulton Controls Corp.

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 if permitted by local codes.

WARNING

FAILURE TO CORRECT BACK DRAFTS WILL CAUSE AIR CONTAMINA TION AND UNSAFE CONDITIONS.

Vent connectors serving appliances vented by natural draft shall not be connected into any portion of mechanical draft systems operating under positive pressure.

After it has been determined that each appliance remaining connected to the common venting system properly vents when tested as outlined above, return doors, windows, exhaust fans, fireplace dampers and any other gas burning appliance to their previous conditions of use.

Any improper operation of the common venting system should be corrected so the installation conforms with the latest edition of CAN/CGA B149.1-00 (latest edition). When resizing any portion of the common venting system, the common venting system should be resized to approach the minimum size as determined using the appropriate tables in Appendix G in CAN/CSA B149.1-00.

4. MULTIPLE VENT T ABLE

3. CONNECTING BOILER TO A COMMON VENT Do not connect the boiler to a common vent or chimney with solid

fuel burning equipment. This practice is prohibited by many local building codes as is the practice of venting gas fired equipment to the duct work of ventilation systems.

Where a separate vent connection is not available and the vent pipe from the boiler must be connected to a common vent with oil burning equipment, the vent pipe should enter the common vent or chimney at a point ABOVE the flue pipe from the oil fired unit.

Where two or more appliances vent into a common vent connector or manifold, the area of the common vent or vent connector should at least equal the area of the largest vent connector plus 50% of the areas of the additional draft hood outlets.

When removing a boiler from a system with a common vent, use the following steps:

Be sure the other appliances connected to the common vent are not in operation.

Seal any unused openings in the common venting system. Visually inspect the venting system for proper size and horizontal

pitch and determine there is no blockage or restriction, leakage, corrosion and other deficiencies which could cause an unsafe condition.

Table 9 has been compiled to show the material sizes in a Type B doublewall combined vent system. Refer to CAN/CSA B149 .1-00 (latest edition), or the ASHRAE Equipment Volume for further information.

A combined vent system is one in which two or more boilers at one level are attached to a common vent.

In order to use table 9, the connector rise and total vent height must be known. Connector rise is vertical distance from the draft hood outlet to the point where the manifold connection is made. Total vent height is the least vertical distance from a draft hood outlet to the top of the vent. Local codes or utility requirements often govern termination height. ULC listed doublewall gas vents, up through 24" (610mm) diameter, can be installed in heated and unheated areas and can pass through floors, ceilings, partitions, walls and roofs, provided the required one inch clearance is observed. These vents should be installed in accordance with CAN/CSA B149.1-00 (latest edition).

EXAMPLE SHOWING USE OF THE HWB/HW-610 COMBINED VENT SIZING TABLE 9

1983

WARNING

Ensure sufficient supply and ventilation air . Under no circumstances should the equipment room where the boiler is installed ever be under negative pressure. Insufficient air supply can interfere with combustion and ventilation of this boiler resulting in unsafe conditions.

Insofar as is practical, close all building doors and windows and all doors between the space in which the appliances remaining connected to the common venting system are located and other spaces of the building. Turn on clothes dryers and any appliance not connected to the common venting system. Turn on any exhaust fans, such as range hoods and bathroom exhausts, so they will operate at maximum speed. Close fireplace dampers.

Place in operation the appliance being inspected. Follow the lighting instructions. Adjust thermostat so appliance will operate continuously.

Test for spillage at the draft hood relief opening after five minutes of main burner operation. Use the flame of a match or candle.

1313

FIGURE 8

TABLE 9, COMBINED VENT SIZING T ABLES

Input: 300,000 Btuh Draft Hood Outlet 8"

MODEL HW/HWB-300 BOILER

Required Connector or Smoke Pipe Diameter

Connector Total Vent Height(Measured in Feet Above Draft Hood)

Rise in 10 15 20 30 40 50 60 80 100

Feet Connector Diameter (in Inches)

1 101010101010101010 2 101010101010101010 3 101010101010101010

4 or more

Number Total Total Vent Height(Measured in Feet Above Draft Hood)

if Units Input 10 15 20 30 40 50 60 80 100

Combined Btuh x 1000 Manifold and Common Vent Diameter (in Inches)*

2 600 14 12 12 12 10 10 10 10 10 3 900 16 14 14 14 12 12 12 12 12 4 1200 18 16 16 14 14 14 14 12 12

MODEL HW/HWB-399 BOILER

Input: 399,000 Btuh Draft Hood Outlet 10"

Required Connector or Smoke Pipe Diameter

Connector Total Vent Height(Measured in Feet Above Draft Hood)

Rise in 10 15 20 30 40 50 60 80 100

Feet Connector Diameter (in Inches)

1 121212121212121212 2 121212101010101010 3 121010101010101010

4 or more 10 10 10 10 10 10 10 10 10

Number Total Total Vent Height(Measured in Feet Above Draft Hood)

if Units Input 10 15 20 30 40 50 60 80 100

Combined Btuh x 1000 Manifold and Common Vent Diameter (in Inches)*

2 798 14 14 14 12 12 12 12 12 12 3 1197 18 16 16 14 14 14 14 14 12 4 1596 20 20 18 16 16 16 14 14 14

MODEL HW/HWB-420 BOILER

Input: 420,000 Btuh Draft Hood Outlet 10"

Required Connector or Smoke Pipe Diameter

Connector Total Vent Height(Measured in Feet Above Draft Hood)

Rise in 10 15 20 30 40 50 60 80 100

Feet Connector Diameter (in Inches)

1 121212121212121212 2 121212101010101010 3 121010101010101010

4 or more 10 10 10 10 10 10 10 10 10

Number Total Total Vent Height(Measured in Feet Above Draft Hood)

if Units Input 10 15 20 30 40 50 60 80 100

Combined Btuh x 1000 Manifold and Common Vent Diameter (in Inches)*

2 840 14 14 14 12 12 12 12 12 12 3 1260 18 16 16 14 14 14 14 14 12 4 1680 20 20 18 16 16 16 14 14 14

Input: 610,000 Btuh Draft Hood Outlet 12"

MODEL HW/HWB-610 BOILER

Required Connector or Smoke Pipe Diameter

Connector Total Vent Height(Measured in Feet Above Draft Hood)

Rise in 10 15 20 30 40 50 60 80 100

Feet Connector Diameter (in Inches)

1 161414141414141414 2 141414141412121212 3 141412121212121212

4 or more 12 12 12 12 12 12 12 12 12

Number Total Total Vent Height(Measured in Feet Above Draft Hood)

if Units Input 10 15 20 30 40 50 60 80 100

Combined Btuh x 1000 Manifold and Common Vent Diameter (in Inches)*

2 1220 18 18 16 16 14 14 14 14 14 3 1830 22 20 20 18 18 16 16 16 14 4 2440 26 24 22 20 20 18 18 18 16 5 3050 28 26 26 24 22 22 20 20 18 6 3660 32 28 28 26 24 24 22 22 20 7 4270 34 32 30 28 26 24 24 22 22 8 4880 36 34 32 30 28 26 26 24 24

9 5490 38 36 34 30 30 28 28 26 24 10 6100 40 38 36 32 30 30 28 26 26 1 1 6710 42 38 38 34 32 30 28 28 26 12 7320 44 42 38 36 34 32 32 30 28

MODEL HW/HWB-670 BOILER

Input: 660,000 or 670,000 Btuh Draft Hood Outlet 12"

Required Connector or Smoke Pipe Diameter

Connector Total Vent Height(Measured in Feet Above Draft Hood)

Rise in 10 15 20 30 40 50 60 80 100

Feet Connector Diameter (in Inches)

1 161414141414141414 2 141414141412121212 3 141412121212121212

4 or more 12 12 12 12 12 12 12 12 12

Number Total Total Vent Height(Measured in Feet Above Draft Hood)

if Units Input 10 15 20 30 40 50 60 80 100

Combined Btuh x 1000 Manifold and Common Vent Diameter (in Inches)*

2 1340 18 18 16 16 14 14 14 14 14

3 2010 22 20 20 18 18 16 16 16 14

4 2680 26 24 22 20 20 18 18 18 16

5 3350 28 26 26 24 22 22 20 20 18

6 4020 32 28 28 26 24 24 22 22 20

7 4690 34 32 30 28 26 24 24 22 22

8 5360 36 34 32 30 28 26 26 24 24

9 6030 38 36 34 30 30 28 28 26 24 10 6700 40 38 36 32 30 30 28 26 26 1 1 7370 42 38 38 34 32 30 28 28 26 12 8040 46 44 40 38 36 34 34 32 30

Input: 520,000 Btuh Draft Hood Outlet 10"

MODEL HW/HWB-520 BOILER

Required Connector or Smoke Pipe Diameter

Connector Total Vent Height(Measured in Feet Above Draft Hood)

Rise in 10 15 20 30 40 50 60 80 100

Feet Connector Diameter (in Inches)

1 141414121212121212 2 121212121212121212 3 121212121010101010

4 or more 12 12 12 12 10 10 10 10 10

Number Total Total Vent Height(Measured in Feet Above Draft Hood)

if Units Input 10 15 20 30 40 50 60 80 100

Combined Btuh x 1000 Manifold and Common Vent Diameter (in Inches)*

2 1040 16 16 14 14 14 14 12 12 12 3 1560 20 18 18 16 16 14 14 14 14 4 2080 22 22 20 18 18 18 16 16 14 5 2600 26 24 22 20 20 18 18 18 18 6 3120 28 26 24 22 22 20 20 18 18 7 3640 30 28 26 24 24 22 22 20 20 8 4160 32 30 28 26 24 24 22 22 20

Known: (5) model HWB/HW-610 boilers. (See illustration).

Connector rise - 2' (Note 1' is minimum). Total vent height 30'.

Problem: Determine diameter of connector, manifold and

common vent.

Procedure: Enter the top of the HWB/HW-610 table (total vent height)

at 30' and the side at 2' (connector rise). A 14" connector diameter is indicated for each connector rise.

To determine the manifold and common vent size, enter this table (total vent height) at 30 and the side at 5 boilers. A manifold diameter of 24" (610mm) is indicated.

1414

VENTING MAINTENANCE - ST ANDARD VENTING

It is recommended that the heating surfaces and vent piping of the appliance be checked every six months for dust, deterioration and carbon deposits. Remove all soot or other obstructions from chimney and flue which will retard free draft. Replace any damaged or deteriorated parts of the venting system.

Qualified servicers should follow this procedure when the boiler’s external heating surfaces and vent pipe need cleaning.

CAUTION

DO NOT USE A NYLON BRUSH OR OTHER STA TIC CREATING MATERIAL TO CLEAN DUST AND CARBON DEPOSITS FROM HEA TING SURFACES AND VENT.

SUCH DEPOSITS ARE FLAMMABLE AND MAY BE IGNITED BY STATIC ELECTRICITY . USE A METAL BRUSH TO MINIMIZE THE DANGER OF EXPLOSION.

1. Turn off the electrical power (main manual gas shutoff and pilot valves, if applicable).

gas vent properly by passing a lighted match or taper around the edge of the relief opening of the draft hood. If the chimney or gas vent is drawing properly, the match flame will be drawn into the draft hood. If not, the combustion products will tend to extinguish this flame. IF THE COMBUSTION PRODUCTS ARE ESCAPING FROM THE RELIEF OPENING OF THE DRAFT HOOD, DO NOT OPERA TE THE EQUIPMENT UNTIL PROPER ADJUSTMENT OR REPAIRS ARE MADE TO PROVIDE ADEQUA TE DRAFT THROUGH THE CHIMNEY OR GAS VENT.”

D. Next, turn on all other fuel burning appliances within the same

room so they will operate at their full input. Repeat step C above, checking the draft on each appliance.

Allow boiler parts and vent to cool before disassembly.

2. Remove the boiler draft diverter and vent pipe running to the chimney.

• Check parts and chimney for obstructions and clean as

necessary.

3. Remove burner from boiler and other metal parts as required to clean and vacuum the heat exchanger and combustion coils.

• Refer to parts list supplied with this manual for

disassembly aid.

4. Reinstall the parts removed in steps 2 and 3.

• Be sure the vent pipe has a minimum upward pitch of one

quarter inch per foot of length (21mm/m) and is sealed as necessary.

5. Restore electrical power and gas supply to boiler.

• Place boiler in operation by following the lighting

instructions in this manual.

• Check for gas leaks and proper boiler and vent operation.

VENTING - SIDEWALL

(OPTIONAL) POWER VENT SYSTEM

If you are installing the optional Power Vent Kit, refer to your HWB/HW Power Vent Kit Inst allation Instructions for proper wiring and installation procedures. Contact your local A.O. Smith representative for details.

VENTING SYSTEM

HA VE VENTING SYSTEM CHECKED EVERY SIX MONTHS FOR OBSTRUCTIONS AND/OR DETERIORA TION IN VENT PIPING.

FIGURE 9

SAFETY RELIEF V AL VES

Your local code authority may have other specific relief valve requirements not covered below.

W ARNING

THE PURPOSE OF A SAFETY RELIEF VALVE IS TO AVOID EXCESSIVE PRESSURE OR TEMPERATURE INTO THE STEAM RANGE WHICH MAY CAUSE SCALDING AT FIXTURES, TANK EXPLOSION, SYSTEM OR BOILER DAMAGE.

TO AVOID SCALDING OR WATER DAMAGE A DRAIN LINE MUST BE CONNECTED TO A RELIEF VALVE TO DIRECT DISCHARGE TO A SAFE LOCATION. A DRAIN LINE MUST NOT BE REDUCED FROM THE SIZE OF THE VALVE OUTLET AND IT MUST NOT CONT AIN ANY V ALVES BETWEEN THE BOILER AND THE RELIEF VAL VE OR THE RELIEF V AL VE AND THE DRAIN EXIT. IN ADDITION, THERE SHOULD NOT BE ANY RESTRICTIONS IN A DRAIN LINE NOR SHOULD IT BE ROUTED THROUGH AREAS WHERE FREEZING CONDITIONS MIGHT OCCUR. DO NOT THREAD OR CAP THE DRAIN LINE EXIT . RESTRICTING OR BLOCKING A DRAIN LINE WILL DEFEAT THE PURPOSE OF THE RELIEF VALVE AND MAY CREATE AN UNSAFE CONDITION. INSTALL A DRAIN LINE WITH A DOWNWARD SLOPE SUCH THA T IT NA TURALL Y DRAINS ITSELF.

If any safety relief valve is replaced, the replacement valve must comply with the latest version of the ASME Boiler and Pressure Vessel Code, Section IV or CSA B51, as applicable. Select a relief valve with a discharge NOT less than the boiler input, and a pressure rating NOT exceeding the working pressure of any component in the system.

A. Insofar as is practical, close all doors, windows and air inlets

to the building. Turn on all exhaust fans (range hood, bathroom exhaust, etc.) so they will operate at their maximum speed. Close fireplace dampers.

B. After allowing appliance to operate for five minutes, test for

spillage at the draft hood relief opening.

C. “CHECKING THE DRAFT. Operate vent connected gas

utilization equipment for several minutes and check to see that the combustion products are going up the chimney or

A. O. Smith supplies Canadian HW boilers for hot water supply systems with a 125 psi pressure relief valve. This valve must be installed in the water outlet as near to the boiler as possible.

A. O. Smith United States HW and Canadian HWB boilers for space heating are shipped with a 50 psi pressure relief valve. This valve must be installed in the water outlet as near to the boiler as possible.

An ASME rated temperature and pressure relief valve must be installed on each and every water storage tank in a hot water supply system.

1515

The storage tank temperature and pressure (T & P) relief valve must comply with the applicable construction provisions of the Standard for Relief Valves and Automatic Gas Shutoff Devices for Hot Water Supply Systems, Z21.22 and/or CAN1-4.4. The T & P valve must be of the automatic reset type and not embody a single-use type fusible plug, cartridge or linkage.

The T & P relief valve should have a maximum temperature rating

of 100

C (2100F), a pressure rating NOT exceeding the lowest rated working pressure of any system component, and a discharge capacity exceeding the total input of the water boilers supplying water to the storage tank.

Locate the T & P relief valve (a) in the top of the storage tank, or (b) in the side of the tank on centerline within the upper 6 inches from the top of the tank. See figures 20 to 31. Tapping shall be threaded in accordance with the latest version of the Standard for Pipe Threads, General Purpose (inch), ANSI/ASME B1.20.1

The boiler, when installed, must be electrically bonded to ground in accordance with the requirements of the authority having jurisdiction or, in the absence of such requirements, with the National Electrical Code, ANSI/NFPA 70 and/or the Canadian Electrical Code Part 1, CSA C22.1, Electrical Code.

STRICT ADHERENCE TO PIPING AND WIRING DIAGRAMS IS REQUIRED TO PREVENT CONSTANT PUMP OPERATION WHEN SYSTEM TEMPERA TURE CONTROL IS SA TISFIED. OTHERWISE THE WARRANTY IS VOID AS STIPULATED IN THE LIMITED WARRANTY ON THE INSTRUCTIONS MANUAL.

The electrical connections must be made so that the circulator will operate before the gas valve opens. At no time may the controlling system allow the burner to fire when there is no water flow through the boilers.

Refer to the diagrams in fig’s. 10 thru 11C for proper wiring sequence with conventional single boiler installations.

Mark location with a Class lll label. See ANSI Z21.10.1, Part 1, MARKING, See CAN/CSA B149.1-00.

WIRING CONNECTIONS

CAUTION

LABEL ALL WIRES PRIOR TO DISCONNECTION WHEN SERVICING CONTROLS. WIRING ERRORS CAN CAUSE IMPROPER AND DANGEROUS OPERA TION. VERIFY PROPER OPERA TION AFTER SERVICING.

1. CONVENTIONAL INST ALLATIONS ALL ELECTRICAL WORK MUST BE INST ALLED IN ACCORDANCE

WITH NATIONAL ELECTRICAL CODE, ANSI/NFP A 70 AND/OR THE CANADIAN ELECTRICAL CODE, P ART 1, CSA C22.1, ELECTRICAL CODE AND MUST CONFORM TO LOCAL REGULATIONS.

The THERMAL BALANCER shown is factory included by A. O. Smith as part no. 98190. This device serves as a pump shutdown delay switch to balance the rising boiler water temperature to system temperature before the pump stops. Overshooting of boiler temperature is prevented and stack loss after shutdown is negligible.

WARNING

AN ELECTRICAL GROUND IS REQUIRED TO REDUCE RISK OF ELECTRIC SHOCK OR POSSIBLE ELECTROCUTION. Make the ground connection to the screw provided in the electrical supply junction box on the boiler.

IF ANY OF THE ORIGINAL WIRE, AS SUPPLIED WITH THE APPLIANCE, MUST BE REPLACED, IT MUST BE REPLACED WITH TYPE 105 SENSOR AND IGNITION CABLE WHICH ARE 2500C AND WIRES CONNECTED TO THE COIL PROTECTOR WHICH ARE 2000C.

C WIRE OR ITS EQUIVALENT , EXCEPT FOR THE FLAME

1616

CONNECTION DIAGRAM

HWB & HW-300, -399, -420, -500 & -610

(NATURAL GAS)

SINGLE ST AGE I.I.D. - ROBERTSHAW® GAS V ALVE

HWB & HW-300, -399, -420, -520, -610 (NATURAL GAS ONL Y) - CANADIAN MODELS

® Robertshaw is a registered trademark of Fulton Controls Corp.

FIGURE 10

1717

CONNECTION DIAGRAM

HWB, HW-420,-520, -610

(PROP ANE GAS)

SINGLE STAGE PROP ANE - ROBERTSHAW GAS V AL VE

24 VOL T -HW, HWB-420, -520, -610 CANADIAN MODELS

FIGURE 11

1818

CONNECTION DIAGRAM HWB & HW 300, 399

(PROP ANE GAS)

FIGURE 13

SINGLE STAGE PROP ANE ROBERTSHA W GAS V ALVE

24 VOLT - HWB, HW -300, 399 CANADIAN MODELS

FIGURE 11A

1919

HW-300, HW-399, HW-420, HW-500 & HW-670

(NA TURAL GAS)

SINGLE ST AGE I.I.D. - ROBERTSHAW GAS V ALVE

HW-300, -399, -420, -520 & 670 (NA TURAL GAS ONL Y) - U.S. MODELS

FIGURE 11B

2020

HW-300, HW-399, HW-420, HW-500 & HW-670

(PROP ANE GAS)

FIGURE 12

SINGLE ST AGE I.I.D. - ROBERTSHAW GAS V ALVE

HW-300, -399, -420, -520 & 670 (PROP ANE GAS ONL Y) - U.S. MODELS

FIGURE 11C

2121

TYPICAL WIRING DIAGRAM (IID NATURAL GAS) FOR SINGLE BOILER LINEAR-TEMP® INSTALLA TION FOR CANADIAN MODELS

FIGURE 12

LINEAR-TEMP INSTALLA TIONS

2. Control for these systems is decided mainly by the type of building

system controlling that is desired. A single boiler installation might be controlled directly from space temperature thermostat(s). Multiple boiler installations are more effective when the boilers are sequenced in and out of operation by some form of main water temperature controller. With one to three boilers, individual controls set at progressive temperatures may be used. For more than three or four boilers, a step controller is recommended.

Individual boiler controls, or the separate stages of a step controller , should fire a boiler and also start the boiler loop circulator whenever the first boiler of a group supplied by that boiler loop is fired. Some large installations may require the firing of more than one boiler per stage.

The system or primary circulator may or may not be controlled by the boiler sequencer. When this pump is operated through the first switch of any type of step controller, care should be taken to determine if a motor starter is needed due to insufficient switch capacity.

If the primary pump is controlled by a manual switch or any other controllers, the electric current supply to the boiler group should be through the primary pump controller. The fast response of A. O. Smith boilers eliminates any need to maintain boiler temperature when the system is satisfied. Wiring should always prevent firing of boiler(s) when there is no water flow in the mains.

Installation diagrams show flow switches in the outlet piping from each boiler as good protection against any boiler being fired when the boiler loop circulator is not in operation. These flow switches will also serve as protection if there is a loss of water.

Outdoor vent systems will normally require an automatic shutdown control if there is a continuous recirculating main and/or if the entire building is not under control of space temperature thermostats. A single bulb outdoor sensing control will prevent overheating of halls, stairways or other uncontrolled areas. There are occasions when outdoor temperatures are temporarily too warm for even a moderate amount of heating in these areas.

Space temperature controlling can be varied to meet the building requirements. Either the single thermostat, as shown, or multiple zone thermostats should control a common relay. This relay controls electric power to the system primary circulator and to the main water temperature controller. This provides for water movement in the system before the main temperature controller can start the secondary circulating pump or fire the boiler.

Figure 12 shows a typical wiring diagram for a single boiler space heating installation. The boiler may be controlled by a main temperature controller as shown or may include outdoor reset if desired. The boiler shown is the model HW-610 with single stage firing, typical of HW models.

Figure 13 shows a layout for various choices of controls often found in commercial heating. These layouts are not intended to be wiring diagrams and only show the relation of one device to another in the system.

Figure 13 is a typical layout of controls for two boilers with one circulator and including optional outdoor reset and thermal balancer. If a secondary circulator is used with each boiler, arrangement for boiler no. 2 will be as shown for boiler no. 1.

Commercial size installations are always best when designed to individual building requirements.

The layout in figure 13 is typical of many combination possibilities to meet the requirements of different buildings. Brand names of controls shown are suggestions and not directly related to any particular type of system. THESE LAYOUTS ARE NOT WIRING DIAGRAMS.

A.O. Smith offers accessory Sequencing Control Panels;

TEK-252 for 2 Stage Boiler Control TEK-254 for 4 Stage Boiler Control TEK-258 for 8 stage Boiler Control

For more information contact A.O. Smith Product Service Department at 1-800-433-2545.

2222

NOTE:

1. Building temperature controls supply electric power to building circulator.

2. Main flow switch proves main water flow before energizing sequencing and resetting controls.

CONTROL APPLICA TION DIAGRAM - TWO BOILER LINEAR-TEMP® INST ALLA TION WITH TWO CIRCULATOR S

FIGURE 13

3. Outdoor thermostat required if building controls do not provide automatic shutdown of reset controls during warm weather.

Boilers and Secondary Circulator are Controlled by

• Dual Bulb, Dual Switch Controller Staging and Outdoor Reset of Main Water Temperature

NOTE:

1. Building temperature controls supply electric power to building circulator.

2. Main flow switch proves main water flow before energizing sequencing and resetting controls.

3. Outdoor thermostat required if building controls do not provide automatic shutdown of reset controls during warm weather.

CONTROL APPLICA TION DIAGRAM - THREE BOILER LINEAR-TEMP® INST ALLA TION WITH THREE CIRCULATORS

FIGURE 14

2323

Boilers and Secondary Circulator are Controlled by

• One Dual Bulb, Dual Switch Mechanical Controller and

• One Dual Bulb, single Switch Mechanical Controller

Sequencing and Outdoor Reset of Main Water Temperature.

NOTE:

1. Building temperature controls supply electric power to building circulator.

2. Main flow switch proves main water flow before energizing sequencing and resetting controls.

3. Outdoor thermostat required if building controls do not provide automatic shutdown of reset controls during warm weather.

Boilers and Secondary Circulator are Controlled by Dual Bulb, Dual Switch Controller Staging and Outdoor Reset of Main Water Temperature

CONTROL APPLICA TION DIAGRAM - FOUR BOILER LINEAR-TEMP® INST ALLATION WITH TWO CIRCULATORS

NOTE:

1. Building temperature controls supply electric power to building circulator.

2. Main flow switch proves main water flow before energizing sequencing and resetting controls.

3. Outdoor thermostat required if building controls do not provide automatic shutdown of reset controls during warm weather.

4. Should motor load exceed 7.5 AMPS, use relays or motor starters.

5. In absence of main flow switch and low water cutoff, jumper "A" and "B" together.

FIGURE 15

Boilers and Secondary Circulator areControlled by Dual Bulb, Dual Switch Controller Staging and Outdoor Reset of Main Water Temperature

CONTROL APPLICA TION DIAGRAM - EIGHT BOILER LINEAR-TEMP® INST ALLA TION WITH INDIVIDUAL CIRCULA TORS

FIGURE 16

2424

CER-TEMP 80 - 1 UNIT INSTALLATION - FOR HOT WATER SUPPLY APPLICATION

CANADIAN MODELS, JUNCTION BOX W/6 TERMINALS

FIGURE 17

CER-TEMP 80 - 1 UNIT INSTALLATION - FOR HOT WATER SUPPLY APPLICATION

U.S. MODELS, JUCNTION BOX W/4 TERMINALS

FIGURE 18

FIGURE 19

2525

CER-TEMP 80 - 2 OR 3 UNIT INSTALLATION - FOR HOT WATER SUPPLY APPLICATION

CANADIAN MODELS, JUNCTION BOX W/6 TERMINALS

FIGURE 20

2626

SCHEMATIC

CANADIAN MODELS, JUNCTION BOX W/6 TERMINALS

FIGURE 21

2727

CER-TEMP 80 - 2 OR 3 UNIT INSTALLATION CONNECTION DIAGRAM

(FOR HOT WATER SUPPLY APPLICATION)

U.S. MODELS, JUNCTION BOX W/4 TERMINALS

FIGURE 22

2828

CER-TEMP 80 - 2 OR 3 UNIT INSTALLATION SCHEMATIC DIAGRAM

(FOR HOT WATER SUPPLY APPLICATION)

U.S. MODELS, JUNCTION BOX W/4 TERMINALS

FIGURE 23

2929

BOOSTER - RECOVERY WIRING DIAGRAM

CANADIAN MODELS, JUNCTION BOX W/6 TERMINALS

FIGURE 24

SHURE-TEMP BOOSTER - RECOVERY WIRING DIAGRAM

(TWO TEMPERATURE SYSTEM)

CANADIAN MODELS, JUNCTION BOX W/6 TERMINALS

FIGURE 25

3030

BOOSTER - RECOVERY WIRING DIAGRAM

U.S. MODELS, JUNCTION BOX W/4 TERMINALS

FIGURE 26

SHURE - TEMP BOOSTER - RECOVER Y WIRING DIAGRAM

TWO-TEMPERATURE SYSTEM

U.S. MODELS, JUNCTION BOX W/4 TERMINALS

FIGURE 27

3131

WA TER LINE CONNECTIONS

T ANK TEMPERA TURE CONTROL

This section provides detailed installation diagrams for typical methods of application for the unit using a Cer-Temp 80 Recovery System (for one temperature water), and either Booster-Recovery or the Shure-Temp Booster-Recovery System (for two temperature water).

These diagrams will serve to provide the installer with a reference for the materials and methods of piping necessary for installation. It is essential that all water and gas piping, vent connections, electrical wiring, and check and flow regulating valves be installed as shown on the diagrams.

Consult the installation diagrams for appropriate locations to install the safety flow switch(es), drain valves, thermometers, relief valves and the circulating pump(s). Apply suitable pipe thread sealing compounds to only the male threads of parts to be connected. If any of these parts are being replaced in a functioning system, remember to shut off the manual gas and control valve(s) and close off the water inlet(s). Open a nearby faucet to relieve pressure and/or drain the boiler or system before attempting to install the new parts.

Check the diagrams thoroughly before starting installation to avoid errors and minimize time and materials cost.

If the system is to be filled with water for testing or other purposes during cold weather and before actual operation, care must be taken to prevent a downdraft entering the boiler or freezing air from contacting the system. Failure to do so may cause the water in the system to freeze with resulting damage to the system. Damage due to freezing is not covered by the warranty.

This equipment must be protected against loss of water or loss of water flow by the installation of a safety flow switch in the outlet piping from the boiler. Piping and wiring diagrams show the application of the accessory package for this purpose.

HARD WA TER

Where hard water conditions exist, water softening or the threshold type of water treatment is recommended. This will protect the dishwashers, coffee urns, water boilers, water piping and other equipment. When water softening or water treatment is not practical, a comparatively easy method of periodic lime removal from the boiler may be employed by installing gate valves, drain valve and acid fill opening as shown in CLEANING AND FLUSHING section of this manual.

The water temperature in the storage tank is controlled by the Tank Temperature Control. The sensing element is mounted inside the hot water storage tank, see fig's. 31-38.

DANGER

HOT WATER TEMPERATURES REQUIRED FOR AUTOMATIC DISHWASHER AND LAUNDRY USE CAN CAUSE SCALD BURNS RESULTING IN SERIOUS PERSONAL INJURY AND/OR DEATH. THE TEMPERATURE A T WHICH INJURY OCCURS V ARIES WITH THE PERSON’S AGE AND TIME OF EXPOSURE. THE SLOWER RESPONSE TIME OF CHILDREN, AGED OR DISABLED PERSONS INCREASES THE HAZARDS TO THEM. NEVER ALLOW SMALL CHILDREN TO USE A HOT WATER TAP, OR TO DRAW THEIR OWN BATH W ATER. NEVER LEA V E A CHILD OR DISABLED PERSON UNATTENDED IN A BATHTUB OR SHOWER.

The tank temperature control is adjustable from 100°F (37.7°C) to 220°F (104.4°C). It is recommended that lower water temperatures be used to avoid the risk of scalding. It is further recommended, in all cases, that the water temperature be set for the lowest temperature which satisfies the user’s hot water needs. This will also provide the most energy efficient operation of the water heater and minimize scale formation.

THE WA TER HEA TER SHOULD BE LOCA TED IN AN AREA WHERE THE GENERAL PUBLIC DOES NOT HAVE ACCESS TO SET TEMPERATURES. SETTING THE WATER TEMPERATURE AT 120°F (49°C) WILL REDUCE THE RISK OF SCALDS. Some states

or provinces require settings at specific lower temperatures. Below you will find listed the approximate time-to-burn relationship for normal adult skin. Valves for reducing point-of-use temperature by mixing cold and hot water are available. Also available are inexpensive devices that attach to faucets to limit hot water temperatures. Contact a licensed plumber or the local plumbing authority.

DET AIL OF T ANK FITTING USED WITH MODIFIED RECOVERY

AND BOOSTER RECOVERY PIPING DIAGRAMS

FIGURE 28

3232

Temperature Time to Produce 2nd & 3rd

Setting Degree Burns on Adult Skin

OVER: 170°F (77°C) Nearly instantaneous

160°F (71°C) About 1/2 second 150°F (65°C) About 1-1/2 seconds 140°F (60°C) Less than 5 seconds 130°F (54°C) About 30 seconds 120°F (49°C) More than 5 minutes

USE ANTI-SCALD VALVE(S) in the hot water system to reduce the risks of scalds at points of use such as lavatories, sinks and bathing facilities.

A float type or an electronic probe type low water cutoff may be used. The manufacturer's installation instructions must be followed.

THERMOMETERS

Thermometers should be obtained and field installed as shown in the installation diagrams.

Thermometers are installed in the system as a means of detecting a possible liming condition in the boiler. An increase of 3°C (5°F) over the normal temperature rise through the boiler is an indication that lime is present. The term "temperature rise" designates the difference between the boiler inlet and outlet water temperature.

A change in water temperature in the storage tank lower than the Tank Temperature Control setting will cause the sensor to close its contacts and consequently energize the boiler.

If the Tank Temperature Control is out of calibration, replace it with a new one; do not attempt to fix this control.

WARNING

SHOULD OVERHEA TING OCCUR OR THE GAS SUPPL Y F AIL T O SHUT OFF, TURN OFF THE MANUAL GAS CONTROL V ALVE TO THE APPLIANCE.

LOW WA TER CUTOFF

A low water cutoff is a safety device which is installed in the boiler piping to prevent the boiler from firing in the event of inadequate water levels in the boiler system.

Where required by local code, this optional device is to be installed in the boiler piping at a level above that of the heat exchanger.

An increase of 3°C (5°F) above the recorded temperature rise may signify a liming condition in the coils or heat exchanger. Refer to CLEANING AND FLUSHING section of this manual for deliming instructions.

Record temperature rise at initial start-up for future reference.

DRAIN V AL VE (Not Supplied)

A drain valve must be obtained and installed on each boiler and tank for draining purposes, see installation diagrams in this manual.

CLOSED W ATER SYSTEM

This boiler should not be installed in a closed water system without taking steps to reduce excessive system pressure due to thermal expansion. Contact the water supplier or local plumbing inspector on how to control this situation.

3333

ONE HW-300, HW-399, HW-420, HW-520, HW-610 OR ONE HW-670 UP-FLOW MODEL

COMMERCIAL BOILER WITH VERTICAL T ANK

TEMPERATURE SETTING SHOULD NOT EXCEED SAFE USE

DANGER

TEMPERATURE AT FIXTURES. SEE TANK TEMPERATURE CONTROL WARNING ON PAGE 32. IF HIGHER PREHEAT TEMPERATURES ARE NECESSARY TO OBTAIN ADEQUATE BOOSTER OUTPUT , ADD AN ANTI-SCALD V ALVE FOR HOT WATER SUPPLIED TO FIXTURES.

IMPORTANT THE INSTALLA TION OF SAFETY FLOW SWITCH AS SHOWN IS REQUIRED TO PROTECT THE BOILER IN CASE OF WA TER SERVICE INTERRUPTION OR CIRCULAT OR F AILURE (A.O. SMITH PKG. NO. 211480).

+ PIPING AND FITTINGS BETWEEN GATE VALVES AND

BOILERS SHOULD BE BRASS OR BRONZE. OTHER PIPING SHOULD CONFORM TO LOCAL CODES.

GATE VA LVES ARE SHOWN FOR SERVICING BOILER. HOWEVER, LOCAL CODES SHALL GOVERN THEIR USAGE.

* PRESSURE RELIEF VALVE RATING SHOULD NOT

EXCEED PRESSURE CAPACITY OF A NY COMPONENT IN THE SYSTEM.

** INSTALL THERMOMETER AND PRESSURE RELIEF IN

OPENINGS PROVIDED ON HW-520, HW-610 & HW-670.

USE THIS TABLE FOR CORRECT

PUMP AND W A TER PIPE SIZE

Minimum B & G *Armstrong

Model Pipe Size Pump Pump

Number (Inches) Size Size

HW-300 1-1/4" 125 S-25 1-1/4" HW-399 1-1/2" 1-1/2" HV H-32 1-1/2" HW-420 1-1/2" 1-1/2" HV H-32 1-1/2" HW-520 1-1/2" 1-1/2" HV H-32 1-1/2"

HW-610/670 2" 2" S-35

*Assumes 50 equivalent feet pf piping or less.

WIRING - FIGURES 17, 18, 19

INSTALL IN ACCORDANCE

WITH ALL LOCAL CODES

FIGURE 29

3434

ONE HW-300, HW-399, HW-420, HW-520, HW-610 OR ONE HW-670 UP-FLOW MODEL

COMMERCIAL BOILER WITH HORIZONT AL T ANK

IMPORTANT THE INSTALLA TION OF SAFETY FLOW SWITCH AS SHOWN IS REQUIRED TO PROTECT THE BOILER IN CASE OF WATER SERVICE INTERRUPTION OR CIRCULATOR FAILURE (A.O. SMITH PKG. NO. 211480).

+ PIPING AND FITTINGS BETWEEN GATE VALVES AND

BOILERS SHOULD BE BRASS OR BRONZE. OTHER PIPING SHOULD CONFORM TO LOCAL CODES.

GATE VALVES ARE SHOWN FOR SERVICING BOILER. HOWEVER, LOCAL CODES SHALL GOVERN THEIR USAGE.

* PRESSURE RELIEF VALVE RA TING SHOULD NOT EXCEED

PRESSURE CAPACITY OF ANY COMPONENT IN THE SYSTEM.

** INSTALL THERMOMETER AND PRESSURE RELIEF IN

OPENINGS PROVIDED ON HW-520, HW-610 & HW-670.

TEMPERATURE SETTING SHOULD NOT EXCEED SAFE USE

DANGER

WIRING - FIGURES 17, 18, 19

INSTALL IN ACCORDANCE

WITH ALL LOCAL CODES

USE THIS TABLE FOR CORRECT

PUMP AND W A TER PIPE SIZE

Minimum B & G *Armstrong

Model Pipe Size Pump Pump

Number (Inches) Size Size

HW-300 1-1/4" 125 S-25 1-1/4" HW-399 1-1/2" 1-1/2" HV H-32 1-1/2" HW-420 1-1/2" 1-1/2" HV H-32 1-1/2" HW-520 1-1/2" 1-1/2" HV H-32 1-1/2"

HW-610/670 2" 2" S-35

*Assumes 50 equivalent feet pf piping or less.

FIGURE 30

3535

TWO HW-399's, HW-420's, HW-520's, HW-610's or HW-670's UP-FLOW MODEL

COMMERCIAL BOILER WITH VERTICAL T ANK, CER-TEMP 80

IMPORTANT THE INSTALLATION OF SAFETY FLOW SWITCH AS SHOWN IS REQUIRED TO PROTECT THE BOILER IN CASE OF W ATER SER VICE INTERRUPTION OR CIRCULATOR FAILURE (A.O. SMITH PKG. NO. 211480).

+ PIPING AND FITTINGS BETWEEN GATE VALVES AND BOILERS

SHOULD BE BRASS OR BRONZE. OTHER PIPING SHOULD CONFORM TO LOCAL CODES.

GATE VALVES ARE SHOWN FOR SERVICING BOILER. HOWEVER, LOCAL CODES SHALL GOVERN THEIR USAGE.

* PRESSURE RELIEF VALVE RATING SHOULD NOT EXCEED

PRESSURE CAP ACITY OF A NY COMPONENT IN THE SYSTEM.

** INSTALL THERMOMETER AND PRESSURE RELIEF IN

OPENINGS PROVIDED ON HW-520, HW-610 & HW-670.

TEMPERATURE SETTING SHOULD NOT EXCEED SAFE USE TEMPERA TURE AT FIXTURES. SEE TANK TEMPERATURE CONTROL WARNING ON PAGE 32. IF HIGHER PREHEAT TEMPERATURES ARE NECESSARY TO OBTAIN ADEQUATE BOOSTER OUTPUT, ADD AN ANTI-SCALD V AL VE FOR HOT WATER SUPPLIED TO FIXTURES.

WIRING - FIGURES 20, 21, 22, OR 23

DANGER

HEA TERS SPACED 30" AP ART

INSTALL IN ACCORDANCE

WITH ALL LOCAL CODES

USE THIS TABLE FOR CORRECT

PUMP AND W A TER PIPE SIZE

MinimumPipe Size B & G *Armstrong

Model (Inches) Pump Pump

Number A B Size Size

HW-300 2" 1-1/2" 2" S-35 HW-399 2" 1-1/2" 2" S-35 HW-420 2" 1-1/2" 2" S-35 HW-520 2" 1-1/2" 2" S-35

HW-610/670 2-1/2" 1-1/2" 2-1/2" S-45 2-1/2"

*Assumes 50 equivalent feet pf piping or less.

FIGURE 31

3636

TWO HW-300's, HW-399's, HW-420's, HW-520's, HW-610's OR HW-670's UP-FLOW MODEL

COMMERCIAL BOILER WITH HORIZONT AL T ANK

IMPORTANT THE INSTALLA TION OF SAFETY FLOW SWITCH AS SHOWN IS REQUIRED TO PROTECT THE BOILER IN CASE OF WATER SERVICE INTERRUPTION OR CIRCULATOR FAILURE (A.O. SMITH PKG. NO.211480).

+ PIPING AND FITTINGS BETWEEN GATE VALVES AND

BOILERS SHOULD BE BRASS OR BRONZE. OTHER PIPING SHOULD CONFORM TO LOCAL CODES.

GATE VALVES ARE SHOWN FOR SERVICING BOILER. HOWEVER, LOCAL CODES SHALL GOVERN THEIR USAGE.

* PRESSURE RELIEF V AL VE RA TING SHOULD NOT EXCEED

PRESSURE CAPACITY OF ANY COMPONENT IN THE SYSTEM.

** INSTALL THERMOMETER AND PRESSURE RELIEF IN

OPENINGS PROVIDED ON HW-520, HW-610 & HW-670.

WIRING - FIGURES 20, 21, 22 or 23

INST ALL IN ACCORDANCE

WITH ALL LOCAL CODES

*Assumes 50 equivalent feet pf piping or less.

FIGURE 32

3737

DANGER

USE THIS TABLE FOR CORRECT

PUMP AND W A TER PIPE SIZE

MinimumPipe Size B & G *Armstrong

Model (Inches) Pump Pump

Number A B Size Size

HW-300 2" 1-1/2" 2" S-35 HW-399 2" 1-1/2" 2" S-35 HW-420 2" 1-1/2" 2" S-35 HW-520 2" 1-1/2" 2" S-35

HW-610/6 70 2-1/2" 1-1/2" 2-1/2" S-45 2-1/2"

THREE HW-520's, HW-610's OR HW-670's UP-FLOW MODEL

COMMERCIAL BOILER WITH VERTICAL T ANK, CER-TEMP 80

WIRING - FIGURES 20, 21, 22 OR 23

INSTALL IN ACCORDANCE

WITH ALL LOCAL CODES

TEMPERATURE SETTING SHOULD NOT EXCEED SAFE USE TEMPERA TURE AT FIXTURES. SEE TANK TEMPERATURE CONTROL WARNING ON PAGE 32. IF HIGHER PREHEAT TEMPERATURES ARE NECESSARY TO OBTAIN ADEQUATE BOOSTER OUTPUT , ADD AN ANTI-SCALD V AL VE FOR HOT WATER SUPPLIED TO FIXTURES.

IMPORT ANT THE INSTALLATION OF SAFETY FLOW SWITCH AS SHOWN IS REQUIRED TO PROTECT THE BOILER IN CASE OF WATER SERVICE INTERRUPTION OR CIRCULATOR FAILURE (A.O. SMITH PKG. NO. 211480).

+ PIPING AND FITTINGS BETWEEN GATE VALVES AND BOILERS SHOULD BE

BRASS OR BRONZE. OTHER PIPING SHOULD CONFORM TO LOCAL CODES.

GA TE VAL VES ARE SHOWN FOR SERVICING BOILER. HOWEVER, LOCAL CODES SHALL GOVERN THEIR USAGE.

* PRESSURE RELIEF VALVE RATING SHOULD NOT EXCEED PRESSURE

CAPACITY OF ANY COMPONENT IN THE SYSTEM.

** INSTALL THERMOMETER AND PRESSURE RELIEF IN OPENINGS PROVIDED

ON HW-520, HW-610 & HW-670.

USE THIS TABLE FOR CORRECT

PUMP AND W A TER PIPE SIZE

MinimumPipe Size B & G *Armstrong

Model (Inches) Pump Pump

Number A B Size Size

HW-520 2-1/2" 1-1/2" 2" S-45 2-1/2"

HW-610/670 3" 1-1/2" 3" HD-3 S-46

*Assumes 50 equivalent feet pf piping or less.

FIGURE 33

DANGER

3838

THREE HW-520's, HW-610's OR HW-670's UP-FLOW MODEL

COMMERCIAL BOILER WITH HORIZONT AL T ANK, CER-TEMP 80

TEMPERATURE SETTING SHOULD NOT EXCEED SAFE USE TEMPERA TURE AT

DANGER

FIXTURES. SEE TANK TEMPERATURE CONTROL WARNING ON PAGE 32. IF HIGHER PREHEAT TEMPERATURES ARE NECESSARY TO OBTAIN ADEQUATE BOOSTER OUTPUT, ADD AN ANTI-SCALD V AL VE FOR HOT WATER SUPPLIED TO FIXTURES.

IMPORTANT THE INSTALLATION OF SAFETY FLOW SWITCH AS SHOWN IS REQUIRED TO PROTECT THE BOILER IN CASE OF WATER SERVICE INTERRUPTION OR CIRCULATOR FAILURE (A.O. SMITH PKG. NO. 211480).

+ PIPING AND FITTINGS BETWEEN GATE VALVES AND BOILERS SHOULD BE

BRASS OR BRONZE. OTHER PIPING SHOULD CONFORM TO LOCAL CODES.

GATE V AL VES ARE SHOWN FOR SERVICING BOILER. HOWEVER, LOCAL CODES SHALL GOVERN THEIR USAGE.

* PRESSURE RELIEF VALVE RATING SHOULD NOT EXCEED PRESSURE

CAPACITY OF ANY COMPONENT IN THE SYSTEM.

** INSTALL THERMOMETER AND PRESSURE RELIEF IN OPENINGS PROVIDED

ON HW-520, HW-610 & HW-670.

USE THIS TABLE FOR CORRECT

PUMP AND W A TER PIPE SIZE

MinimumPipe Size B & G *Armstrong

Model (Inches) Pump Pump

Number A B Size Size

HW-520 2-1/2" 1-1/2" 2" S-45 2-1/2"

HW-610/670 3" 1-1/2" 3" HD-3 S-46

*Assumes 50 equivalent feet pf piping or less.

FIGURE 34

3939

WIRING - FIGURES 20, 21, 22, OR 23

HEATERS SP ACED 24" APAR T

INSTALL IN ACCORDANCE

WITH ALL LOCAL CODES

BOOSTER RECOVERY SYSTEM (P A TENTED)

TWO TEMPERA TURE SYSTEM WITHOUT RECIRCULATION

ONE HW-300, HW-399, HW-420, HW-520, HW-610 OR HW-670 UP-FLOW MODEL

COMMERCIAL BOILER WITH VERTICAL T ANK

TEMPERATURE SETTING SHOULD NOT EXCEED SAFE USE TEMPERA TURE AT

DANGER

IMPORTANT THE INSTALLATION OF SAFETY FLOW SWITCH AS SHOWN IS REQUIRED TO PROTECT THE BOILER IN CASE OF WATER SERVICE INTERRUPTION OR CIRCULATOR FAILURE (A.O. SMITH PKG. NO. 211480).

+ PIPING AND FITTINGS BETWEEN GA TE VALVES AND BOILERS SHOULD BE

BRASS OR BRONZE. OTHER PIPING SHOULD CONFORM TO LOCAL CODES.

GA TE VAL VES ARE SHOWN FOR SERVICING BOILER. HOWEVER, LOCAL CODES SHALL GOVERN THEIR USAGE.

* PRESSURE RELIEF VALVE RATING SHOULD NOT EXCEED PRESSURE

CAPACITY OF ANY COMPONENT IN THE SYSTEM.

** INSTALL THERMOMETER AND PRESSURE RELIEF IN OPENINGS PROVIDED

ON HW-520, HW-610 & HW-670.

WIRING - FIGURE 25 OR 27

INST ALL IN ACCORDANCE

WITH ALL LOCAL CODES

USE THIS TABLE FOR CORRECT

PUMP AND W A TER PIPE SIZE

Minimum B & G *Armstrong

Model Pipe Size Pump Pump

Number (Inches) Size Size

HW-300 1-1/4" 125 S-25 1-1/4" HW-399 1-1/2" 1-1/2" HV H-32 1-1/2" HW-420 1-1/2" 1-1/2" HV H-32 1-1/2" HW-520 1-1/2" 1-1/2" HV H-32 1-1/2"

HW-610/670 2" 2" S-35

*Assumes 50 equivalent feet pf piping or less.

FIGURE 35

4040

BOOSTER RECOVERY SYSTEM (P ATENTED)

TWO TEMPERA TURE SYSTEM WITHOUT RECIRCULATION

ONE HW-300, HW-399, HW-420, HW-520, HW-610 OR HW-670 UP-FLOW MODEL

COMMERCIAL BOILER WITH HORIZONT AL T ANK

TEMPERATURE SETTING SHOULD NOT EXCEED SAFE USE TEMPERATURE AT

DANGER

FIXTURES. SEE TANK TEMPERATURE CONTROL WARNING ON PAGE 32. IF HIGHER PREHEAT TEMPERATURES ARE NECESSARY TO OBTAIN ADEQUATE BOOSTER OUTPUT , ADD AN ANTI-SCALD V ALVE FOR HOT W ATER SUPPLIED TO FIXTURES.

IMPORT ANT THE INSTALLATION OF SAFETY FLOW SWITCH AS SHOWN IS REQUIRED TO PROTECT THE BOILER IN CASE OF WATER SERVICE INTERRUPTION OR CIRCULATOR FAILURE (A.O. SMITH PKG. NO. 211480).

+ PIPING AND FITTINGS BETWEEN GATE V AL VES AND BOILERS SHOULD BE

BRASS OR BRONZE. OTHER PIPING SHOULD CONFORM TO LOCAL CODES.

GA TE VAL VES ARE SHOWN FOR SER VICING BOILER. HOWEVER, LOCAL CODES SHALL GOVERN THEIR USAGE.

* PRESSURE RELIEF VALVE RATING SHOULD NOT EXCEED PRESSURE

CAPACITY OF ANY COMPONENT IN THE SYSTEM.

** INST ALL THERMOMETER AND PRESSURE RELIEF IN OPENINGS PROVIDED

ON HW-520 & HW-610.

USE THIS TABLE FOR CORRECT

PUMP AND W A TER PIPE SIZE

Minimum B & G *Armstrong

Model Pipe Size Pump Pump

Number (Inches) Size Size

HW-300 1-1/4" 125 S-25 1-1/4" HW-399 1-1/2" 1-1/2" HV H-32 1-1/2" HW-420 1-1/2" 1-1/2" HV H-32 1-1/2" HW-520 1-1/2" 1-1/2" HV H-32 1-1/2"

HW-610,670 2" 2" S-35

*Assumes 50 equivalent feet pf piping or less.

WIRING - FIGURE 25 OR 27

INST ALL IN ACCORDANCE

WITH ALL LOCAL CODES

PIPE SIZES "B"

CIRCULA TING LOOP TO DISHWASHER

Type L Copper Tubing

Allowable Distance from Heater to Dishwasher (Feet./Meters)

Pressure

Drop (PSI) 25" 50" 75" 100" 175" 200" 250" 300"

(7.6m) (15m) (22.8m) (30m) (53m) (60m) (76m) (91m)

10 1/2 3/4 3/4 3/4 3/4 3/4 1 1 20 1/2 1/2 1/2 3/4 3/4 3/4 3/4 3/4 30 1/2 1/2 1/2 1/2 3/4 3/4 3/4 3/4 40 1/2 1/2 1/2 1/2 1/2 3/4 3/4 3/4 50 1/2 1/2 1/2 1/2 1/2 3/4 3/4 3/4

FAIRL Y ROUGH PIPE

Allowable Distance from Heater to Dishwasher (Feet./Meters)

Pressure

Drop (PSI) 25" 50" 75" 100" 175" 200" 250" 300"

(7.6m) (15m) (22.8m) (30m) (53m) (60m) (76m) (91m)

10 3/4 3/4 3/4 3/4 1 1 1 1 20 1/2 3/4 3/4 3/4 3/4 3/4 3/4 1 30 1/2 1/2 3/4 3/4 3/4 3/4 3/4 3/4 40 1/2 1/2 3/4 3/4 3/4 3/4 3/4 3/4 50 1/2 1/2 1/2 3/4 3/4 3/4 3/4 3/4

NOTE: Allowable pressure drop is the difference in PSI between supply

water pressure and the 20 PSI required at the dishwasher.

FIGURE 36

4141

BOOSTER RECOVERY SYSTEM (P A TENTED) - TWO TEMPERA TURE SYSTEM WITHOUT RECIRCULATION

ONE HW-300, HW-399, HW-420, HW-520, HW-610 OR HW-670 UP-FLOW MODEL

COMMERCIAL BOILER WITH HORIZONT AL TANK

TEMPERATURE SETTING SHOULD NOT EXCEED SAFE USE TEMPERA TURE AT

DANGER

FIXTURES. SEE TANK TEMPERATURE CONTROL WARNING ON PAGE 32. IF HIGHER PREHEAT TEMPERATURES ARE NECESSARY TO OBTAIN ADEQUATE BOOSTER OUTPUT , ADD AN ANTI-SCALD V AL VE FOR HOT WATER SUPPLIED TO FIXTURES.

IMPORTANT THE INSTALLATION OF SAFETY FLOW SWITCH AS SHOWN IS REQUIRED TO PROTECT THE BOILER IN CASE OF WATER SERVICE INTERRUPTION OR CIRCULATOR FAILURE (A.O. SMITH PKG. NO. 211480).

+ PIPING AND FITTINGS BETWEEN GATE V AL VES AND BOILERS SHOULD BE

BRASS OR BRONZE. OTHER PIPING SHOULD CONFORM TO LOCAL CODES.

GATE V A LVES ARE SHOWN FOR SER VICING BOILER. HOWEVER, LOCAL CODES SHALL GOVERN THEIR USAGE.

* PRESSURE RELIEF VALVE RATING SHOULD NOT EXCEED PRESSURE

CAPACITY OF ANY COMPONENT IN THE SYSTEM.

** INSTALL THERMOMETER AND PRESSURE RELIEF IN OPENINGS PROVIDED

ON HW-520, HW-610 & HW-670.

WIRING - FIGURE 24 OR 26

INST ALL IN ACCORDANCE

WITH ALL LOCAL CODES

FIGURE 37

4242

USE THIS TABLE FOR CORRECT

PUMP AND W A TER PIPE SIZE

Minimum B & G *Armstrong

Model Pipe Size Pump Pump

Number (Inches) Size Size

HW-300 1-1/4" 125 S-25 1-1/4" HW-399 1-1/2" 1-1/2" HV H-32 1-1/2" HW-420 1-1/2" 1-1/2" HV H-32 1-1/2" HW-520 1-1/2" 1-1/2" HV H-32 1-1/2"

HW-610/670 2" 2" S-35

*Assumes 50 equivalent feet pf piping or less.

BOOSTER RECOVERY SYSTEM (P ATENTED)

TWO TEMPERATURE SYSTEM WITHOUT RECIRCULATION ONE HW-300, HW-399, HW-420, HW -520,HW-610 OR HW-670

UP-FLOW MODEL COMMERCIAL BOILER WITH VERTICAL T ANK

WIRING - FIGURE 24 OR 26

INST ALL IN ACCORDANCE

WITH ALL LOCAL CODES

TEMPERATURE SETTING SHOULD NOT EXCEED SAFE USE TEMPERATURE AT FIXTURES. SEE TANK TEMPERATURE CONTROL WARNING ON PAGE 32. IF HIGHER PREHEAT TEMPERATURES ARE NECESSARY TO OBTAIN ADEQUATE BOOSTER OUTPUT , ADD AN ANTI-SCALD V AL VE FOR HOT WATER SUPPLIED TO FIXTURES.

IMPORT ANT THE INSTALLATION OF SAFETY FLOW SWITCH AS SHOWN IS REQUIRED TO PROTECT THE BOILER IN CASE OF WATER SERVICE INTERRUPTION OR CIRCULATOR FAILURE (A.O. SMITH PKG. NO. 211480).

FIGURE 38

INSTRUCTIONS FOR NUMBERED CONTROLS SHOWN ABOVE -

1 DUAL T ANK TEMPERATURE CONTROL

The dual tank temperature control should be installed in the lower of the two 3/4" thermostat openings in the tank.

Left Dial -High Limit

Adjust to 160°F with 20°F differential (minimum).

Right Dial -Tank Temperature

Adjust to 140°F with 8°F differential (minimum).

• May be adjusted slightly higher if total demand of

F water requires higher tank temperature.

180

DANGER

+ PIPING AND FITTINGS BETWEEN GATE VALVES AND BOILERS SHOULD BE

BRASS OR BRONZE. OTHER PIPING SHOULD CONFORM TO LOCAL CODES.

GATE V AL VES ARE SHOWN FOR SERVICING BOILER. HOWEVER, LOCAL CODES SHALL GOVERN THEIR USAGE.

* PRESSURE RELIEF VALVE RATING SHOULD NOT EXCEED PRESSURE

CAPACITY OF ANY COMPONENT IN THE SYSTEM.

** INSTALL THERMOMETER AND PRESSURE RELIEF IN OPENINGS PROVIDED

ON HW-520, HW-610 & HW-670.

4 FLOW REGULATING PLUG COCK

(For Boiler Flow Rate Adjustment)

A slight closing of this valve may be necessary to set proper water flow rate for 40°F temperature rise through the boiler. Temperature rise is observed between the boiler inlet and outlet thermometers.

5 FLOW REGULATING PLUG COCK

(For Dishwasher Recirculating Loop)

Close this valve just enough to divert sufficient flow into circulating loop that will maintain 180°F at end of loop adjacent to dishwasher when dishwasher is not drawing water.

2 LINE TEMPERATURE CONTROL

Install as close to boiler as possible. Do not insulate piping or tee immediately adjacent to the control.

Adjust dial to 185°F with 5°F differential (minimum).

• May be set slightly higher if radiant loss from piping prevents maintaining 180°F at dishwasher.

3 BOILER LIMIT CONTROL

(Hi Limit adjust dial 220°F with 10°F differential)

6 WA TER PRESSURE REDUCING VAL VE

Entering water pressure to the dishwasher must be set for 20 psig flow pressure. Excessive flow pressure may waste rinse water beyond the capacity of the boiler to maintain it at 180°F temperature.

7 INLET/OUTLET THERMOMETERS

See A. O. Smith deliming instructions Form 4778 when normal temperature rise between rinse thermometers starts to increase. Thermometers should be positioned near the inlet and outlet of the heater.

4343

WITH TWO VERTICAL TANKS

WITH THREE VERTICAL T ANKS

TEMPERATURE SETTING SHOULD NOT

DANGER

EXCEED SAFE USE TEMPERATURE AT FIXTURES. SEE TANK TEMPERATURE CONTROL WARNING ON P AGE 32. IF HIGHER PREHEAT TEMPERA TURES ARE NECESSARY TO OBTAIN ADEQUATE BOOSTER OUTPUT , ADD AN ANTI-SCALD VALVE FOR HOT WATER SUPPLIED TO FIXTURES.

FIGURE 39

4444

TWO HORIZONT AL TANK INST ALLA TION

THREE HORIZONTAL T ANK INSTALLA TION

TEMPERATURE SETTING SHOULD NOT EXCEED SAFE

DANGER

USE TEMPERATURE AT FIXTURES. SEE TANK TEMPERATURE CONTROL W ARNING ON PAGE 32. IF HIGHER PREHEAT TEMPERA TURES ARE NECESSARY TO OBTAIN ADEQUATE BOOSTER OUTPUT, ADD AN ANTI-SCALD VALVE FOR HOT WATER SUPPLIED TO FIXTURES.

FIGURE 40

START-UP AND OPERATING INSTRUCTIONS

WARNING After placing boiler into operation, the ignition system safety shutoff device must be tested by the following test method.

1. Reset High Limit Temperature Control to lowest setting.

(See figure 38, page 44).

2. Reset System Controller to maximum setting, causing a call

for heat and allowing unit to run until High Limit Temperature Control trips.

3. Resetting the High Limit Temperature Control to a higher

setting, unit should run.

4. Reset System Controller and High Limit Temperature Control to desired temperature. If unit fails to run, see Trouble-Shooting in this manual.

Before operating the boiler, the entire system must be filled with water, purged of air and checked for leaks. Do not use Stop Leak or other boiler compounds. The gas piping should also be leak tested.

Any safety devices including low water cutoffs used in conjunction with this boiler should receive periodic (every six months) inspection to assure proper operation. A low water cutoff device of the float type should be flushed every six months. All relief valves should be inspected and manually operated at least twice a year.

4545

IMPORTANT

IT IS RECOMMENDED THAT A QUALIFIED PERSON PERFORM THE INITIAL FIRING OF THE BOILER. AT THIS TIME THE USER SHOULD NOT HESITATE TO ASK THE INDIVIDUAL ANY QUESTIONS WHICH HE MAY HAVE IN REGARD TO THE OPERA TION AND MAINTENANCE OF THE UNIT .

FILLING AND VENTING

1. Fast fill system through bypass until pressure approaches desired system pressure. Close bypass valve and permit pressure to be established by the pressure reducing valve.

2. Vent all high points in system to purge system of air.

If pressure bleeding of system is desired, install valves as shown in fig. 1.

Where cast iron radiation and motorized valves are used, conventional system pressure and installation practices should be followed.

Provisions should be made to permit manual venting of radiators or convectors.

PRECAUTIONS

If the unit is exposed to the following, do not operate boiler until all corrective steps have been made by a qualified serviceman:

1. Flooding to level of burner or controls or higher.

2. Exposure to fire.

3. If damaged.

4. Firing without water.

5. Sooting

CAUTION

SHOULD OVERHEATING OCCUR OR THE GAS SUPPL Y F AIL T O SHUT OFF, DO NOT TURN OFF OR DISCONNECT THE ELECTRICAL SUPPL Y TO THE PUMP. INSTEAD, SHUTOFF THE GAS SUPPLY A T A LOCATION EXTERNAL TO THE APPLIANCE.

FIGURE 41

The boiler should be periodically inspected by a qualified servicer for continuous safe operation.

Qualified servicers should follow this procedure when the boiler’s burners need cleaning.

1. Turn off the electrical power and close the main manual gas shutoff valve.

• Allow boiler parts to cool before disassembly.

2. Remove main burner manifold assembly from boiler.

• Refer to parts list supplied with this manual for disassembly aid.

3. Remove any loose foreign material such as dust or lint with a vacuum. Check all ports, orifices, and air openings for blockage. Dislodge any foreign material causing blockage. Remove any soot or carbon deposits with a rag making sure to remove any lint left on burner by vacuuming again.

4. Reinstall the burner manifold assembly on boiler.

5. Restore electrical power and gas supply to boiler.

• Put the boiler back in operation by following the lighting instructions in this manual or on the lighting and operating label on the boiler.

PILOT AND MAIN BURNER

To maintain safe operation and the greatest efficiency from the boiler, check the pilot and the main burner once every six months for proper flame characteristics.

1. MAIN BURNER The main burner, fig. 41, should display the following

characteristics:

• Provide complete combustion of gas.

• Cause rapid ignition and carryover of flame across entire

burner.

• Give reasonably quiet operation during ignition, burning

and extinction.

• Cause no excessive lifting of flame from burner ports.

If the proceeding burner characteristics are not evident, check for accumulation of lint or other foreign material that restricts or blocks the air openings to the burner or boiler.

Also check for good flow of combustion and ventilating air to the unit. Maintain a clear area around the boiler at all times.

• Check for gas leaks and proper boiler and vent operation.

2. PILOT BURNER - ELECTRONIC IGNITION To establish pilot flame without main burner operation, it will

be necessary to perform the following steps:

Servicing of the pilot burner (every six months) includes keeping pilot shield (not shown) free of lint, cleaning the burner head, the primary air opening and the orifice of the pilot burner, fig. 42.

1. Open fused disconnect switch or shut off electrical power to the boiler.

2. Turn the gas valve control knob counterclockwise to the “PILOT” position.

3. Close fused disconnect switch to restore electrical power to the boiler.

The pilot will now ignite provided the combination gas valve knob is set at “PILOT” and the system is calling for

4646

heat.

(Continued on Page49)

LIGHTING AND OPERATING INSTRUCTIONS (NATURAL AND PROPANE GAS WITH I.I.D.)

FOR YOUR SAFETY READ BEFORE OPERATING

WARNING: IF YOU DO NOT FOLLOW THESE INSTRUCTIONS

EXACTLY. A FIRE OR EXPLOSION MAY RESULT CAUSING PROPERTY DAMAGE, PERSONAL INJURY OR LOSS OF LIFE.

WARNING: HOT W A TER CAN PRODUCE 3rd DEGREE

BURNS IN 6 SECONDS A T 140° F. (60° C).

IN CASE OF POWER FAILURE DO NOT ATTEMPT TO OPERATE APPLIANCE. IMPROPER INSTALLATION, ADJUSTMENT , AL TERA TION, SERVICE OR MAINTENANCE CAN CAUSE PROPERTY DAMAGE, PERSONAL INJURY OR LOSS OF LIFE. REFER TO THE USER'S INFORMATION MANUAL PROVIDED WITH THIS APPLIANCE. INST ALLATION AND SERVICE MUST BE PERFORMED BY A QUALIFIED INST ALLER, SERVICE AGENCY OR THE GAS SUPPLIER.

A. THIS APPLIANCE IS EQUIPPED WITH AN IGNITION DEVICE

WHICH AUTOMA TICALL Y LIGHTS THE PILOT. DO TO LIGHT THE PILOT BY HAND.

B. BEFORE OPERATING: SMELL ALL AROUND THE APPLIANCE

AREA FOR GAS. BE SURE TO SMELL NEXT TO THE FLOOR BECAUSE SOME GAS IS HEA VIER THAN AIR AND WILL SETTLE ON THE FLOOR.

NOT TRY

ROBERTSHAW® GAS CONTROL

WHAT TO DO IF YOU SMELL GAS

• DO NOT TRY TO LIGHT ANY APPLIANCE.

• DO NOT TOUCH ANY ELECTRIC SWITCH; DO NOT USE ANY PHONE IN YOUR BUILDING.

• IMMEDIATELY CALL YOUR GAS SUPPLIER FROM A NEIGHBOR’S PHONE. FOLLOW THE GAS SUPPLIER’S INSTRUCTIONS.

• IF YOU CANNOT REACH YOUR GAS SUPPLIER, CALL THE FIRE DEPARTMENT.

C . USE ONLY YOUR HAND TO PUSH IN OR TURN THE GAS

CONTROL KNOB. NEVER USE TOOLS. IF THE KNOB WILL NOT PUSH IN OR TURN BY HAND, DON’T TRY TO REPAIR IT. CALL A QUALIFIED SERVICE TECHNICIAN. FORCE OR ATTEMPTED REPAIR MAY RESULT IN A FIRE OR EXPLOSION.

D. DO NOT USE THIS APPLIANCE IF ANY P ART HAS BEEN UN-

DER WATER. IMMEDIATELY CALL A QUALIFIED SERVICE TECHNICIAN TO INSPECT THE APPLIANCE AND TO REPLACE ANY P ART OF THE CONTROL SYSTEM AND ANY GAS CONTROL WHICH HAS BEEN UNDER W A TER.

® Registered trademark of Robertshaw-Fulton Controls Company

LIGHTING INSTRUCTIONS

1. STOP! READ THE SAFETY INFORMA TION ABOVE.

2. MAKE SURE BOILER AND SYSTEM ARE FILLED WITH WATER AND ALL AIR HAS BEEN EXPELLED FROM APPLIANCE.

3. TURN OFF ELECTRIC POWER TO THE APPLIANCE. SET SYSTEM TEMPERATURE CONTROLLER TO LOWEST SETTING. PURGE ALL GAS LINES OF AIR. DO NOT A TTEMPT TO LIGHT THE PILOT BY HAND.

5. REFER TO DIAGRAMS ABOVE. TURN TOP KNOB OF GAS CONTROL CLOCKWISE TO "OFF" POSITION,

(FIG. A). CLOSE FIRING AND PILOT MANUAL V A LVES, CLOCKWISE .

6. WAIT FIVE (5) MINUTES TO CLEAR OUT ANY GAS. THEN SMELL FOR GAS, INCLUDING NEAR THE FLOOR. IF YOU SMELL GAS, INFORMA TION ABOVE ON THIS LABEL. IF YOU DO NOT SMELL GAS, GO THE NEXT STEP .

STOP! FOLLOW "B" IN THE SAFETY

TO TURN OFF GAS TO APPLIANCE

A. SET THE SYSTEM CONTROLLER TO THE LOWEST

SETTING.

B. TURN OFF ELECTRICAL POWER TO APPLIANCE.

7. TURN TOP KNOB OF GAS CONTROL COUNTERCLOCKWISE FIRING AND PILOT MANUAL VALVES, COUNTERCLOCKWISE

8. TURN ON ALL ELECTRIC POWER TO THE APPLIANCE.

9. SET SYSTEM TEMPERATURE CONTROLLER T O DESIRED SETTING.

10. WHEN CONTROLLER CALLS FOR HEA T , THE CIRCULA T ING PUMP WILL OPERA TE AND THE PILOT BURNER WILL BE SPARK IGNITED. GAS CONTROL WILL OPEN AND MAIN BURNER WILL THEN IGNITE. NOTE: IF PILOT F AILS TO IGNITE, TURN OFF APPLIANCE AND CONSULT YOUR "INSTALLATION AND USERS MANUAL" FOR ADJUST MENTS AND TROUBLESHOOTING.

1 1. IF THE APPLIANCE WILL NOT OPERATE, FOLLOW THE

INSTRUCTIONS "TO TURN OFF GAS TO APPLIANCE" AND CALL YOUR SERVICE TECHNICIAN OR GAS SUPPLIER.

C . TURN TOP KNOB OF GAS CONTROL CLOCKWISE TO

"OFF" POSITION, (FIG. A). CLOSE FIRING AND PILOT MANUAL VA LVES, CLOCKWISE

TO "ON" POSITION, (FIG. B). OPEN

4747

211686-000 Rev.00

LIGHTING AND OPERATING INSTRUCTIONS PROPANE (LP) STANDING PILOT MODELS

FOR YOUR SAFETY READ BEFORE LIGHTING

WARNING: IF YOU DO NOT FOLLOW THESE INSTRUCTIONS EXACTLY. A FIRE OR EXPLOSION MAY RESULT CAUSING PROPERTY DAMAGE, PERSONAL INJURY OR LOSS OF LIFE.

WARNING: HOT WATER CAN PRODUCE 3rd DEGREE

BURNS IN 6 SECONDS A T 140° F. (60° C).

IN CASE OF POWER FAILURE DO NOT ATTEMPT TO OPERATE APPLIANCE. IMPROPER INSTALLATION, ADJUSTMENT, ALTERATION, SERVICE OR MAINTENANCE CAN CAUSE PROPERTY DAMAGE, PERSONAL INJURY OR LOSS OF LIFE. REFER TO THE USER'S INFORMA TION MANUAL PROVIDED WITH THIS APPLIANCE. INSTALLATION AND SERVICE MUST BE PERFORMED BY A QUALIFIED INST ALLER, SER VICE AGENCY OR THE GAS SUPPLIER.

A. THIS APPLIANCE IS EQUIPPED WITH A ST ANDING PILOT WHICH

MUST BE LIGHTED BY THE PUSH BUTTON IGNITER. WHEN LIGHTING THE PILOT, FOLLOW THESE INSTRUCTIONS EXACTLY.

B. BEFORE LIGHTING: SMELL ALL AROUND THE APPLIANCE AREA

FOR GAS. BE SURE TO SMELL NEXT TO THE FLOOR BECAUSE SOME GAS IS HEAVIER THAN AIR AND WILL SETTLE ON THE FLOOR.

ROBERTSHAW® GAS CONTROL

LIGHTING INSTRUCTIONS

WHAT TO DO IF YOU SMELL GAS

• DO NOT TRY TO LIGHT ANY APPLIANCE.

• DO NOT TOUCH ANY ELECTRIC SWITCH; DO NOT USE ANY PHONE IN YOUR BUILDING.

• IMMEDIATELY CALL YOUR GAS SUPPLIER FROM A NEIGHBOR’S PHONE. FOLLOW THE GAS SUPPLIER’S INSTRUCTIONS.

• IF YOU CANNOT REACH YOUR GAS SUPPLIER, CALL THE FIRE DEPARTMENT .

C. USE ONLY YOUR HAND TO PUSH IN OR TURN THE GAS CONTROL

KNOB. NEVER USE TOOLS. IF THE KNOB WILL NOT PUSH IN OR TURN BY HAND, DON’T TRY TO REPAIR IT. CALL A QUALIFIED SERVICE TECHNICIAN. FORCE OR ATTEMPTED REPAIR MAY RESUL T IN A FIRE OR EXPLOSION.

D. DO NOT USE THIS APPLIANCE IF ANY PART HAS BEEN

UNDER WATER. IMMEDIATELY CALL A QUALIFIED SERVICE TECHNICIAN TO INSPECT THE APPLIANCE AND TO REPLACE ANY P ART OF THE CONTROL SYSTEM AND ANY GAS CONTROL WHICH HAS BEEN UNDER W A TER.

® Registered trademark of Robertshaw-Fulton Controls Company

1. STOP! READ THE SAFETY INFORMA TION ABOVE .

2. MAKE SURE BOILER AND SYSTEM ARE FILLED WITH W A TER AND ALL AIR HAS BEEN EXPELLED FROM APPLIANCE.

3. TURN OFF ELECTRIC POWER TO THE APPLIANCE. SET SYSTEM TEMPERA TURE CONTROLLER TO LOWEST SETTING . PURGE ALL GAS LINES OF AIR.

4. REFER TO DIAGRAMS ABOVE. TURN TOP KNOB OF GAS CONTROL CLOCKWISE TO "OFF" POSITION, (FIG. A). CLOSE FIRING AND PILOT MANUAL VALVES, CLOCKWISE .

5. WAIT FIVE (5) MINUTES T O CLEAR OUT ANY GAS. THEN SMELL FOR GAS, INCLUDING NEAR THE FLOOR. IF YOU SMELL GAS,

STOP! FOLLOW "B" IN THE SAFETY INFORMA TION ABOVE

ON THIS LABEL. IF YOU DO NOT SMELL GAS, GO TO THE NEXT STEP.

6. PILOT CAN BE VIEWED THROUGH THE PILOT PEEP HOLE. SEE ILLUSTRA TION 1.

7. OPEN FIRING AND PILOT MANUAL VALVES, COUNTERCLOCKWISE .

8. TURN TOP KNOB OF GAS CONTROL COUNTERCLOCKWISE TO "PILOT" POSITION. (FIG. C)

9. PUSH AND HOLD TOP KNOB DOWN, THIS ALLOWS GAS TO FLOW TO PILOT.

10. DEPRESS PUSH BUTTON IGNITER, WHICH CAUSES SP ARK TO JUMP ACROSS ELECTRODE, IGNITING PILOT. CONTINUE TO HOLD DOWN TOP KNOB FOR APPROXIMATELY 30 SECONDS

TO TURN OFF GAS TO APPLIANCE

A. SET THE SYSTEM CONTROLLER TO THE LOWEST SETTING. B. TURN OFF ELECTRICAL POWER TO APPLIANCE. C. TURN TOP KNOB OF GAS CONTROL CLOCKWISE TO "OFF"

OR UNTIL PILOT WILL CONTINUE TO STAY LIT WHEN KNOB IS RELEASED.

• IF THE KNOB DOES NOT POP UP WHEN RELEASED, STOP AND IMMEDIATELY CALL YOUR SERVICE TECHNICIAN OR GAS SUPPLIER.

• IF THE PILOT WILL NOT ST A Y LIT AFTER SEVERAL TRIES, TURN THE GAS CONTROL KNOB TO "OFF" AND CALL YOUR SERVICE TECHNICIAN OR GAS SUPPLIER.

11. OBSERVE PILOT THROUGH PEEP HOLE. ADJUST PILOT FLAME TO HEIGHT OF APPROXIMATELY 3/8" TO 1/2" (9 TO 13mm) BY MEANS OF PILOT GAS REGULA TOR.

12. TURN TOP KNOB OF GAS CONTROL COUNTERCLOCKWISE TO "ON" POSITION. (FIG. B)

13. TURN ON ELECTRIC POWER AND SET SYSTEM TEMPERA TURE CONTROLLER TO DESIRED OPERATING TEMPERATURE. WHEN CONTROLLER CALLS FOR HEAT, THE CIRCULATOR WILL OPERATE. GAS VALVE WILL OPEN AND MAIN BURNER WILL THEN IGNITE.

14. IF THE APPLIANCE WILL NOT OPERATE, FOLLOW THE INSTRUCTIONS "TO TURN OFF GAS APPLIANCE" AND CALL YOUR SERVICE TECHNICIAN OR GAS SUPPLIER.

POSITION, (FIG. A). SEE ABOVE.

D. TURN FIRING AND PILOT MANUAL V AL VES CLOCKWISE TO

CLOSE POSITION.

ILLUSTRATION 1

4848

211688-000 Rev.00

(Continued from Page 46)

4. Adjust pilot flame. To adjust the pilot flame, remove the cap screw from the

pilot adjusting valve and turn to deliver a sufficient flame at the pilot burner to cover 3/8" to 1/2" (10-12mm) of the sensing probe tip. See fig. 42.

• The pilot flame should envelop 3/8 to 1/2 inch of the tip of the thermocouple. Remove pilot adjustment cover screw, fig. 43b. Turn inner adjustment screw or pilot adjusting valve clockwise to decrease, or counterclockwise to increase pilot flame. Be sure to replace cover screw on combination gas valve after adjustment to prevent possible gas leakage.

FIGURE 42

If the pilot burner ignites but the main burner fails to light, check for gas flow to the main burner.

Check for good terminal connection at the sensing probe at the pilot burner assembly.

Check for electrical power to the valve. If electrical power and gas are present at the valve and the valve does not open when system calls for heat, replace valve.

3. PILOT BURNER - NON-I.I.D. MODELS Servicing of the pilot burner (every six months) includes keeping

pilot shield free of lint, cleaning the burner head, the primary air opening and the orifice pilot burner, fig. 43a.

To ensure maximum millivolt output, the pilot burner flame should envelop 3/8 to 1/2 inch of the thermocouple tip in fig. 43a. The electrical output of the thermocouple will be affected by:

FIGURE 43B

2. Clogged pilot burner orifice.

• Clean or replace orifice. A clogged orifice will restrict gas flow and result in low thermocouple output.

3. Incorrect orifice.

• Replace. Orifice size is stamped on the wrench flats.

4. Clogged primary air opening.

• Restricted air passages will soften the pilot flame and result in poor thermocouple flame impingement.

CLOSED CIRCUIT TEST

1. Attach the leads from a millivolt meter to the thermocouple and junction block as shown in fig. 43c.

PIEZO PILOT IGNITOR

FIGURE 43A

1. Low gas pressure

• Adjust pilot flame by means of the pilot gas adjustment located in the gas valve.

FIGURE 43C

• A satisfactory thermocouple will produce a reading of above 14 to 18 millivolts.

2. Transfer the lead on the junction block to other terminal, figure 43d.

• A satisfactory voltage supply through the protector switch will result in a reading of 8 to 14 millivolts.

• If a reading of less than 8 millivolts is obtained, the junction block connections and the protector switch leads must be checked.

4949

PROTECTOR SWITCH CONTINUITY TEST

Do not depress the protector switch reset button prior to testing. The leads from the switch are removed from the thermocouple function block and attached to the leads from a test flashlight.

The model N22T test kit (combination flashlight and continuity tester) is manufactured by the RAY-O-Vac Company, Madison, WI and available through local suppliers.

With the flashlight turned on, the lamp should light. If the lamp lights, the protector switch circuit is closed and in proper working order. If the lamp does not light, the reasons could be:

1. Protector switch contacts open.

FIGURE 43D

The purpose of checking the current ahead and after the protector switch is to measure the millivolt drop across the contacts. This drop should be between 4 and 6 millivolts.

• Depress reset button on switch (switch cannot be reset until water temperature in the boiler coils drop below 200°F). Lamp should light.

2. Defective protector switch or bad leads.

FIGURE 44

5050

• If lamp does not light when reset button is depressed, attach the test flashlight leads to the protector switch terminals. If lamp does not light, switch is defective and must be replaced.

• If lamp does light, the leads are bad and must be repaired or replaced.

CHECKING AND ADJUSTING THE INPUT

1. Follow steps 1 thru 6 of the OPERATING INSTRUCTIONS.

2. Attach a pressure gauge or a manometer to the manifold pressure tapping and refer to table 8 for correct manifold pressure.

3. Follow steps 7 thru 11 of the OPERATING INSTRUCTIONS.

4. Use this formula to “clock” the meter. Be sure that other gas consuming appliances are not ON during this interval.

3600 x H = Btuh T

Btuh = The approximate actual input rate. T = Time in seconds to burn one cubic foot of gas. H = Heating value of the fuel gas in Btu per cubic foot of

gas.

IMPORTANT

UNDER NO CIRCUMSTANCES SHOULD THE GAS INPUT EXCEED THE INPUT SHOWN ON THE BOILER MODEL AND RA TING PLA TE. OVERFIRING COULD RESUL T IN DAMAGE OR SOOTING OF THE BOILER.

Minor variances from input on rating plate can be corrected by adjustment of gas pressure regulators described in GAS PRESSURE REGULATORS section of this manual.

The inlet gas pressure must not exceed or be less than the values shown on rating plate.

CONTROL SETTINGS

MODEL HW-300, HW-399, HW-420, HW-520, HW-610 & HW-670 The high limit is a safety device wired in series with the ignition

system. Set the high limit control to approximately 10 maximum designed system temperature. If the boiler outlet water temperature should exceed the high limit setting, the main gas valve will close but the circulator will continue to operate. Maximum adjustable setting is 115

(45

F) adjustable differential, fig. 45.

C (239°F) cut-out with a 30C (50F) to 250C

F above the

EXAMPLE:

T = 9.0 seconds/ft

H = 1050 Btu/ft3(natural gas) Btuh = ? Gas flow through meter: 3600 x 1050 = 420,000 Btuh

9.0

Small changes in the input rate may be made by adjusting the manifold pressure, see GAS PRESSURE REGULATORS. Under no circumstances should you exceed the maximum input rate for the boiler given in table 2.

5. Repeat steps 1 thru 6 of the OPERATING INSTRUCTIONS.

6. Remove the pressure gauge or manometer from the manifold pressure tapping. Replace the screw-in plug in the manifold pressure tap.

7. Repeat steps 7 thru 11 of the OPERATING INSTRUCTIONS. The boiler will resume normal operation.

When the boiler is operating at full capacity , or full gas input, it should consume 1 cu. ft. of gas in approximately the time indicated in table 10.

FIGURE 45

ELECTRONIC INTERMITTENT PILOT

IGNITION CONTROL

The solid state ignition control, fig. 46, ignites the pilot burner gas by creating a spark at the pilot assembly. Pilot gas is ignited and burns during each running cycle. The main burner and pilot gases are cut off during the “OFF” cycle. Pilot gas ignition is proven by the pilot sensor. Main burner ignition will not occur if the pilot sensor does not first sense pilot ignition.

On models with the igniter control a spark continues to operate for 15 seconds. If pilot ignition fails, there is a 5 minute wait and retry or unit must be manually reset.

This control is non-adjustable and has no serviceable parts. The removal of its cover voids the control warranty and may damage the electronic circuit.

TABLE 10

CONSUMPTION RATE

(Refer to Operating at Full Input or Full Capacity)

TIME TO CONSUME 1 CU. FT.

Heating OF GAS (SECONDS)

Type Value HWB/ HWB/ HWB/ HWB/ HWB/ HWB/

Gas Btu/Ft.^3 HW-300 HW-399 HW-420 HW-520 HW-610 HW-670

Natural 1050 12.6 9.5 9.0 7.3 6.2 5.7

Propane 2500 30.0 22.6 21.4 17.3 14.8 13.4

5151

FIGURE 46

NORMAL OPERA TING SEQUENCE WITH INTERMITTENT

IGNITION CONTROLS (I.I.D.)

1. System control calls for boiler operation.

2. Spark begins at pilot burner.

3. Pilot gas control valve is energized. Gas flows to pilot burner.

4. Pilot burner gas ignites. The sensing probe on the pilot burner senses the presence of the pilot flame. The spark stops after a few seconds.

The input reduction is primarily achieved by reducing the size of the main burner orifices. To do this, the main burner orifices require replacement with orifices sized for the particular installation elevation. When ordering, be sure to state the model number and the altitude of the location where the boiler is being installed.

Upon field deration of the boiler, adjustment to the gas pressure regulator is required. See CHECKING AND ADJUSTING THE INPUT in this manual for inlet and manifold pressure requirements. Also, due to the input rating reduction required at high altitudes, the output rating of the appliance is also reduced and should be compensated for in the sizing of the equipment for applications.

NOTE: If the pilot gas isn’t present or doesn’t ignite after

15 seconds, the spark and pilot gas will stop, wait 5 minutes, and retry or unit must be manually reset..

5. Main gas control valve is energized and main burner gas ignites.

NOTE: If gas interruption occurs during boiler operation, the

sensing probe will detect flame failure and within .8 seconds de-energize the main and pilot burner gas control valves. The operation of the control will revert back to step 2 in the foregoing.

6. System control stops boiler operation. Main and pilot burners are extinguished.

HIGH ALTITUDE INST ALLATIONS

IN CANADA

Acceptance of these models for use at altitudes above 2000 feet (600 m) is based on field test of the individual installation by the provincial/state authority having jurisdiction.

IN THE U.S.A.

WARNING

INSTALLATIONS ABOVE 2000 FEET REQUIRE REPLACEMENT OF THE BURNER ORIFICES IN ACCORDANCE WITH SECTION

8.1.2 OF THE NATIONAL FUEL GAS CODE (ANSI Z223.1). F AILURE

TO REPLACE THE ORIFICES WILL RESULT IN IMPROPER AND INEFFICIENT OPERATION OF THE APPLIANCE RESULTING IN THE PRODUCTION OF INCREASED LEVELS OF CARBON MONOXIDE GAS IN EXCESS OF SAFE LIMITS WHICH COULD RESUL T IN SERIOUS PERSONAL INJUR Y OR DEATH.

For specific orifice requirements, please refer to the appropriate section of the National Fuel Gas Code ANSI Z223.1 or CGA 2.17-M91.

You should contact your gas supplier for any specific changes which may be required in your area.

Ratings specified by manufacturers for most boilers apply for elevations up to 2000 feet (600 m). For elevations above 2000 feet (600 m) ratings must be reduced by a rate of 4% for each 1000 feet (300 m) above sea level.

Example: If a boiler is rated at 610,000 Btu/hr. at sea level, to operate the boiler at 5000 feet (1500 m) it must be derated by 20% (4% x 5) to a new rating of 488,000 Btu/hr.

A. O. Smith does build some models specifically for high altitude service. Please check the rating plate before making changes.

THERMAL BALANCER

Figure 47 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.

2. Apply a light to the black and yellow leads.

• The lamp should not light as the contact in this circuit is normally open when the resistor is cool.

3. Remove the test light.

4. Apply 120 volts to the white and red leads which power the 1900 ohm resistor. After a warming period the contacts of the thermal balancer should operate.

5. Remove the test light.

6. Apply the test light as described in steps 1 and 2. While the resistor is still warm the lamp indications should be

the opposite as described previously.

FIGURE 47

COIL HIGH LIMIT CONTROL

(PROTECTOR SWITCH)

This boiler is equipped with a manual reset protector switch, located under the small cover on the side of the jacket, fig. 48. This device provides positive shutdown of the heater in the event of boiler or system malfunction. Should the surface temperature of the copper tubing heat exchanger reach 120°C (250°F), the protector switch will activate, the gas valve will close, the pilot and main burners will be extinguished. If the protector switch should shut off unit, check the following conditions:

• No water in boiler.

• Restricted water flow through the boiler.

• Improper wiring (boiler firing without circulator operating).

• Pump failure.

After correcting failure condition remove the protector switch cover and push the reset button. The protector switch may be reset after the coil surface temperature cools to .6°C (1°F).

5252

PROTECTOR SWITCH

FIGURE 48

PRESSURE REDUCING V ALVE

The screen in the pressure reducing valve may require occasional cleaning due to foreign material in the water supply. This will restrict the flow and could reduce the effectiveness of purging and prolong filling time. To inspect the screen, close the main water supply valve ahead of the pressure reducing valve and remove the screen for cleaning, see fig’s. 1 and 2.

For proper performance mount the switch in a section of pipe where there is a straight run of at least 5 pipe diameters on each side of the flow switch (i.e. do not locate adjacent to valves, elbows, orifices, etc.).

The flow switch shall be mounted in a standard 1-1/2" x 1-1/2" x 1" tee for a 1-1/2" pipe application. For larger pipe sizes use a reducing tee in order to keep the switch as close to the pipe as possible. Install the flow switch in the branch (top) opening of the reducing tee and provide adequate paddle length in the flow stream. For example in a 2" pipe installation use a 2" x 2" x 1" reducing tee. For 2", or 3" pipe use paddle segments as supplied. For other pipe sizes (i.e. 1-1/4", 1-1/2" and 2-1/2") trim the paddle to the proper pipe size, see fig. 49. If a standard tee is used, install a face or hex bushing in the top opening. The paddle must be adjusted or trimmed to the size of the pipe in which it will be installed.

CAUTION

Any part of the paddle must not touch the pipe or any restrictions in the pipe. Screw the flow switch in position so the flat of the paddle is at right angles to the flow. The arrow on the side case must point in the direction of the flow.

SAFETY FLOW SWITCH

The safety flow switch is a safety device which must be installed at the water outlet of the unit to prevent main burner operation in the event of inadequate water flow through the unit, see fig’s. 10 through 12 and 17 through 27.

An accessory package A. O. Smith No. 211480 containing a safety flow switch is available for this application.

This switch may be mounted in a horizontal pipe line or a vertical pipe line with upward water flow. Do not install the switch where the water flow is downward.

T ABLE 11 - SAFETY FLOW SWITCH

Minimum Pipe Rate

Contacts Closed Contacts Open

Model (Flow) (No Flow)

Number GPM LPS GPM LPS

HWB/HW-300 5.8 0.36 3.7 0.23 HWB/HW-399 7.5 0.47 5.0 0.31 HWB/HW-420 7.5 0.47 5.0 0.31 HWB/HW-520 13.7 0.86 9.5 0.60

HWB/HW-610/670 13.7 0.86 9.5 0.60

The safety flow switch may be field adjusted to obtain higher minimum flow rates than those shown in table 11.

CAUTION

Paddle must be trimmed at the dotted arc. It must not touch the pipe or have any restriction when installed

FIGURE 49

5353

To adjust the flow rate setting:

1. Remove the flow switch cover.

2. For higher flow rate—turn the range adjusting screw clockwise.

Thermal expansion is the normal response of water when it is heated. In a closed system, thermal expansion will cause the system pressure to build until the relief valve actuation pressure is equaled. Then, the relief valve will open, allowing some water to escape, slightly lowering the pressure.

3. For lower flow rate—turn the range adjusting screw counter-clockwise.

CAUTION

The switch is factory set at approximately the minimum flow rate, see Table II. It must not be set lower than the factory setting as this may result in the switch failing to return at a “no flow” condition.

4. Replace the flow switch cover.

Where units are installed in multiples, each boiler must be individually protected by a safety flow switch.

SAFETY RELIEF V AL VE MAINTENANCE

Every six months the system safety relief valves should be checked to ensure that they are in operating condition. To check a relief valve, lift the lever at the end of the valve several times. The valve

should seat properly and operate freely.

CAUTION

BEFORE MANUALLY OPERA TING A RELIEF VALVE, MAKE SURE THAT A DRAIN LINE HAS BEEN ATTACHED TO THE VALVE TO DIRECT THE DISCHARGE TO AN OPEN DRAIN. FAILURE TO TAKE THIS PRECAUTION COULD MEAN CONTACT WITH EXTREMELY HOT WATER EXITING THE VALVE DURING THIS CHECK OPERA TION.

A properly sized expansion tank should be installed.

ABOVE ALL, DO NOT PLUG ANY RELIEF VALVE. THIS IS NOT A SOLUTION AND CAN CREA TE A HAZARDOUS SITUATION.

REPLACEMENT P ARTS

U.S. Models

Replacement parts may be ordered through A. O. Smith dealers, authorized servicers or distributors. Refer to the Yellow Pages for where to call or contact the A. O. Smith Water Products Company, 5621 W. 115th Street, Alsip, IL 60803, 1-800-433-2545. When ordering parts be sure to state the quantity, part number and description of the item including the complete model and serial number as it appears on the product. Refer to the parts lists for more information.

Canadian Models

Replacement parts may be ordered through A. O. Smith dealers, authorized servicers or distributors. Refer to the Yellow Pages for where to call or contact the A. O. Smith Enterprises, Ltd., P. O. Box 310, 768 Erie St., Stratford, Ontario N5A 6T3, 1-800-265-8520. When ordering parts be sure to state the quantity, part number and description of the item including the complete model and serial number as it appears on the product. Refer to the parts lists for more information.

If a relief valve discharges periodically or continuously, it may be due to thermal expansion of water in a closed water supply system, or, it may be due to thermal expansion of water in a closed water supply system, or, it may be due to a faulty relief valve.

QUALITY REPLACEMENT PARTS

REMOVAL OF EXISTING BOILER FROM A COMMON VENTING SYSTEM

At the time of removal of an existing boiler, the following step s shall be followed with each appliance remaining connected to the common venting system placed in operation, while the other appliances remaining connected to the common venting system are not in operation.

Seal any unused openings in the common venting system.

Visually inspect the venting system for proper size and horizontal pitch and determine there is no blockage or restriction, leakage, corrosion and other deficiencies which could cause an unsafe condition.

Place in operation the appliance being inspected. Follow the lighting instructions. Adjust thermostat so appliance will operate continuously.

Test for spillage at the draft hood relief opening after 5 minutes of main burner operation. Use the flame of a match or candle, or smoke from a cigarette, cigar or pipe.

After it has been determined that each appliance remaining connected to the common venting system properly vents when tested as outlined above, return doors, windows, exhaust fans, fireplace dampers and any other gas-burning appliance to their previous condition of use.

Any improper operation of the common venting system should be corrected so the installation conforms with the National Fuel Gas Code, ANSI Z223.1 and/or CAN/CGA B149, Installation Codes. When resizing any portion of the common venting system, the common venting system should be resized to approach the minimum size as determined using the appropriate tables in Appendix F in the National Fuel Gas Code, ANSI Z223.1 and/or CAN/CGA B149 Installation Codes.

5454

GENERAL MAINTENANCE

These boilers are designed to give many years of efficient and satisfactory service when properly operated and maintained. To assure continued good performance, the following recommendations are made.

The area around the unit should be kept clean and free from lint and debris. Sweeping the floor around the boiler should be done carefully. This will reduce the dust and dirt which may enter the burner and pilot air passages, causing improper combustion and sooting.

THE FLOW OF COMBUSTION AND VENTILATION AIR TO THE BOILER MUST NOT BE OBSTRUCTED.

THE BOILER AREA MUST BE KEPT CLEAR AND FREE FROM COMBUSTIBLE MATERIALS, GASOLINE, AND OTHER FLAMMABLE VAPORS AND LIQUIDS.

Periodic checks, at least twice a year, should be made for water and/or gas leaks.

More frequent inspections may be necessary depending on water conditions.

The boiler mounted gas and electrical controls have been designed to give both dependable service and long life. However, malfunction can occur, as with any piece of equipment. It is therefore recommended that all components be checked periodically by a qualified serviceman for proper operation.

RELIEF VAL VE

The safety relief valve should be opened at least twice a year to check its working condition. This will aid in assuring proper pressure relief protection. Lift the lever at the top of the valve several times until the valve seats properly and operate freely.

DANGER

THE WA TER P ASSING OUT OF THE V AL VE DURING CHECKING OPERATION MAY BE EXTREMELY HOT. BEFORE OPERATING RELIEF VALVE MAKE SURE DRAIN LINE IS INSTALLED TO DIRECT DISCHARGE TO A SAFE LOCATION SUCH AS AN OPEN DRAIN, TO A VOID SCALDING OR WA TER DAMAGE.

WARNING

SHOULD OVERHEA TING OCCUR OR THE GAS SUPPL Y F AIL T O SHUT OFF, TURN THE MANUAL GAS CONTROL VALVE TO THE APPLIANCE.

CLEANING AND FLUSHING INSTRUCTIONS

INTERNAL CONT AMINANTS

The hydronic system must be internally cleaned and flushed after a new or replacement boiler has been installed to remove contaminants that may have accumulated during installation. This is doubly important when a replacement boiler is installed into an existing system where Stop Leak or other boiler additives have been used.

Failure to clean and flush the system can produce acid concentrations that become corrosive, cause gases to form that block water circulation or lead to formation of deposits on the boiler surfaces, any of which could result in damage to the system and circulator.

All hot water heating systems should be completely flushed with a grease removing solution to assure trouble-tree operation. Pipe joint compounds, soldering paste, grease on tubing and pipe all tend to contaminate a system.

Failure to flush contaminates from a system can cause solids to form on the inside of boiler exchangers, create excessive amounts of air and other gases to block circulation, foul various system accessories and even deteriorate circulation seals and impellers.

It is recommended that after installation, the boiler and system when filled should include the proper percentage of cleaning solution related to approximate water volume of the system. Fire and circulate for about one hour and then flush clean with fresh water. Commercial grease removing solutions are available from your distributor.

Some solids exist in most water supply systems. As the water is heated, these tend to drop out depositing as scale or lime. This scale is comparatively easy to remove if cleaned before the unit becomes clogged. The time between cleaning will vary depending upon water conditions and usage. A change of about 50F (3°C) in the normal temperature rise through the unit is usually an indication that it is time for preventive maintenance.

Figure 31 shows typical piping arrangement for gravity deliming of lime deposits.

The amount of calcium carbonate (lime) released from water is in direct proportion to water temperature and usage, see fig. 49. The higher the water temperature or water usage, the more lime deposits are dropped out of the water. This is the lime scale which forms in pipes, boilers and on cooking utensils.

Lime accumulation not only reduces the life of the equipment but also reduces efficiency of the boiler and increases fuel consumption.

The usage of water softening equipment greatly reduces the hardness of water. However, this equipment does not always remove all of the hardness (lime). For this reason it is recommended that a regular schedule for deliming be maintained.

HOT WATER SUPPL Y BOILERS

PREVENTIVE MAINTENANCE

DELIMING

5555

The time between cleaning will vary from two to six months depending upon water conditions and usage. A change of approximately 5

F in the normal temperature rise through the boiler is usually an indication that scale should be removed. For long life, copper or brass is recommended for all valves, pipe and fittings used between gate valves “A” and “B” and the boiler, see fig. 51.

Boiler failure due to excessive lime build-up voids the warranty.

9. When foaming action has stopped completely, allow 10 to 15 minutes for the solvent to dissolve any remaining scale in the unit.

10. Open the drain cock and drain all the solvent from unit.

11. Remove standpipe and drain hose assembly from tees. Install fittings originally removed into openings. Open valve “A” allowing fresh water to flow through unit and out drain cock for three to five minutes.

12. Close drain cock and open valve “B”. Restore electric and gas supply.

Check unit for proper operation.

FIGURE 50

DELIMING SOL VENTS

A. O. Smith recommends the use of generic commercially available cleaning solutions to remove lime buildup from your system.

CAUTION

Read the instructions on the label of the deliming solvent container .

REMOVING LIGHT DEPOSITS OF SCALE

1. Shut off electric and gas supply to the unit.

2. Close gate valves “A” and “B”, see fig.51.

3. Open drain cock and drain unit.

4. Remove pressure relief valve from outlet header assembly and install drain hose assembly, see fig. 51.

5. Install standpipe in tee of inlet line, see fig. 51.

6. Close drain cock.

7. Slowly pour required amount of deliming solvent shown below into unit through standpipe. Direct solution into suitable container with hose, see illustration.

8. Continue to fill until foaming action stops.

DELIMING THE HWB/HW BOILER

FIGURE 51

MINIMUM AMOUNT OF CLEANING

SOLUTION REQUIRED

Model

Number Litres Gallons

HWB/HW-300 12 3 HWB/HW-399 19 5 HWB/HW-420 19 5 HWB/HW-520 26 7

HWB/HW-610/670 26 7

HEA VY LIME DEPOSITS

If the solvent does not readily pass through the clogged coils or heat exchanger, it will be necessary to use an acid pump deliming kit, or contact a service agency for proper cleaning.

A. O. Smith part no. 4930 motorized deliming pump kit, complete with pump, hoses, fittings, container and instructions is available from your dealer, distributor or the A. O. Smith Water Products Company.

REMOVING SILICA TE

Ammonium bifluoride flakes (NH4F HF) can be used in conjunction with delimer to delime and remove siliceous materials from copper coil water boilers.

Ammonium bifluoride flakes should be purchased locally from chemical suppliers.

5656

PRE-TROUBLESHOOTING

Before any extensive trouble-shooting, perform the following: Ensure That:

— Voltage (120 vac) is supplied to the appliance. — System control (tank temperature control, thermostat, etc.) is calling

for appliance operation (call for heat).

— Gas supply pressure is within the maximum and minimum operating

ranges listed on the appliance rating plate/label. — Voltage (24 vac) is supplied by transformer . — Appliance is wired according to wiring diagram. Note: Cross wiring the 24 volt circuit of the relay will short the transformer. — All wire terminals/connectors are firmly attached to valves, modules,

switches, limit controls, etc.

— Other contacts (switches) are closed (relay, low water cutoff, flow

switch, coil protector, pressure switch, etc.).

— For LP models only check for possible lockout condition of the ignition

module.

TROUBLESHOOTING

CER-TEMP 80 RECOVERY SYSTEM CHECKOUT PROCEDURE

Use this checkout for Cer-Temp 80 Recovery Systems. (For hot water supply application only)

SYSTEM OPERA TION

Checkout Sequence Contact Incorrect Cause Remedy

Set tank temperature Circulating pump Pump and burner Tank temperature control Replace. control (thermostat) and burner shut remain on. (thermostat) defective. 20°F (10°C) below off. tank water temperature

With thermal System wiring is incorrect. Correct wiring. balancer, pump off delay of approx- Circulating pump Pump wired for continuous Correct wiring. imately 2 minutes. o n. operation.

Burner on. Gas valve stuck or defective. Correct or replace valve.

System wiring is incorrect. Correct wiring.

Set tank temperature Circulating pump Circulating pump High limit control set too Replace. (If problem control (thermostat) and burner on. on. low. proven to be at this 20°F (10°C) above control by applying tank water temperature. High limit control differential jumper to terminals.)

too wide. System wiring is incorrect. Correct wiring. Coil protector switch has Remove control cover,

activated. depress reset button. Gas valve or wiring Check wiring. Repair or

defective. replace valve.

Circulating pump Power off or system Check power supply and burner off. wiring is incorrect. and wiring.

Tank temperature control Replace. (thermostat) defective.

Burner on. System wiring is incorrect. Correct wiring.

Boiler outlet Circulating pump Circulating pump High limit control defective, Replace. temperature exceeds on. and burner on. or set too high (max. should 210°F (100°C). be set at 200°F).

Set tank temperature System maintains. control (thermostat) desired water for desired water temperature. temperature.

5757

CHECKING HONEYWELL S-8600H OR S-8610M

Replace ignition module.

INTERMITTENT IGNITION CONTROLS

NO SPARK AT PILOT BURNER

Turn off gas supply.

Is voltage (24 Vac) across the 24 V terminals on module during “Call for heat”?

Is voltage (24 Vac) across the PV & MV/PV terminals on “call for heat”?

YES

Turn on gas supply.

turn on power supply.

Securely connect cable

and/or ground wire.

Replace pilot burner

and/or ground wire.

Carefully bend downward

top of ground strap

to achieve 1/8”

spark gap.

YES

NOTE: S8610M will automatically reset every 5 minutes. S8600H pilot valve will be de-energized if module goes into lockout condition. Reset system by turning electrical power off or by turning system controller to off or down below "call for heat". Wait one minute, then turn system on.

YES

Turn off power supply.

Is ignition cable firmly plugged into pilot assembly and module?

Is ground wire firmly attached to pilot assembly and GND terminal on module?

YES

Are ignition cable and ground wire in good condition (not brittle, burnt or cracked)?

YES

Ensure ground strap is the closest metal to the igniter/sensor rod (electrode) to prevent the spark from shorting out to other metal parts (pilot screen, pilot shield, etc.).

Ignition cable must not touch metal surfaces or current carrying wires.

Is there a 1/8” gap between ground strap and electrode?

Replace Ignition

Module.

YES

Is the ceramic insulator surrounding the electrode cracked or broken?

YES

Replace pilot burner assembly.

5858

CHECKING HONEYWELL S8600H OR S-8610M

SPARK AT PILOT BURNER BUT PILOT WILL NOT LIGHT

Attach wires firmly.

Replace gas valve.

Turn on power supply

INTERMITTENT IGNITION CONTROLS

Ensure all manual shutoff valves are fully open; All filters are clean; All gas connections are gas tight; Pilot tubing is not damaged, obstructed or kinked; and pilot orifice is unclogged. Check for air in gas line, purge (bleed) line if necessary.

Are the wires securely attached to the pilot operator on the gas control and to the PV & MV/PV terminals on the ignition module?

Install a pressure gauge in the pilot tubing line between the gas control and the pilot burner assembly. Ensure that the pilot adjustment screw (under cap) is adjusted to a position that will permit gas to flow.

Is pilot gas flowing during ignition attempt?

Turn off power supply.

YES

Securely connect

cable and/or ground

wire.

Replace pilot burner

and/or ground wire.

Carefully bend down-

wards top of ground

strap to achieve

1/8” spark gap.

Replace pilot burner.

YES

Are ignition cable and ground wire in good condition (not brittle, burnt, or cracked)?

Is ignition cable firmly plugged into pilot assembly and module?

Is ground wire firmly attached to pilot assembly and GND terminal on module?

YES

Ensure ground strap is the closest metal to the igniter/sensor rod (electrode) to prevent the spark from shorting out to other metal parts (pilot screen, pilot shield, etc.).

Ignition cable must not touch metal surfaces or current carrying wires.

Is there a 1/8” gap between ground strap and electrode?

YES

Is ceramic insulator surrounding the electrode in good condition (not cracked or broken)?

YES

Replace Ignition

Module.

Is there excessive draft conditions that may cause pilot burner ignition problems?

YES

Correct draft problems in a manner that would ensure adequate combustion and ventilation air and proper pilot burner performance.

5959

CHECKING HONEYWELL S-8600H OR S8610M

INTERMITTENT IGNITION CONTROLS

PILOT BURNER LIGHTS BUT MAIN BURNER DOES NOT LIGHT

Replace

ignition

module.

Attach

wires

firmly .

Correct the situation by consulting the installation or user’s manual on how to adjust pilot flame.

Is voltage (24 Vac) across terminals MV & MV/PV?

Are the wires securely attached to the main

valve operator on the gas control and to terminals MV & MV/PV on ignition module?

Replace main gas valve.

Replace pilot burner and/or ground wire.

YES

Does the pilot flame cover 3/8” to 1/2” of ingniter/sensor rod?

YES

Does spark stay on for more than 15 seconds after the pilot is “proven” (lit)?

YES

Ensure the ground wire and ignition cable are separate from each other (prevents shorting out).

Are they in good condition (not brittle, burnt or cracked)?

YES

Replace pilot burner.

Clean rod or replace

pilot burner if necessary.

Is the ceramic insulator surrounding the igniter/sensor rod in good condition (not broken or cracked)?

YES

Is the igniter/sensor rod in good condition (not worn, corroded, sooted or damaged)?

YES

Replace ignition module.

6060

CHECKING HONEYWELL S8600H OR S-8610M

INTERMITTENT IGNITION CONTROLS

NO SPARK AT PILOT BURNER BUT PILOT WILL NOT LIGHT

Turn off gas supply.

Fix connection and/or tighten module to the appliance

Check the circuit providing 24 VAC .

Replace ignition module.

Turn on gas supply and/ or power supply.

Securely connect cable and/or ground wire.

Is there a good connection between terminals? Is module securely attached to appliance for good ground

connection?

YES

Is voltage (24VAC across transformer positive terminal and GND with "call for heat"??

YES

Is voltage (24VAC) across ignition module terminals 24 Volt and GND on "call for heater"?

NOTE: (For LP models only) Pilot Valve will be de-energized if module goes into lockout condition. Reset system by turning electrical power off or by turning system controller down below "call for heat". Wait one minute then turn system on.

YES

Turn off power supply. Is high voltage cable assembly firmly plugged into module?

Is pilot ground wire firmly attached to the pilot assembly and GND terminal on module?

Replace pilot burner and/or ground wire.

Carefully bend down-

wards top of ground

strap to achieve

1/8” spark gap.

Replace Ignition Module.

YES

Are high voltage cable and ground wire in good condition (not brittle, burnt or cracked)?

YES

Make sure pilot flame spreader (hood) is the closest metal to the electrode to prevent the spark from shorting out to other metal parts (pilot screen, pilot shield, etc).

High voltage cable must not touch metal surfaces or current carrying wires.

Is there a 7/64" spark gap between the tip (edge) of the hood and electrode, and is the gap located in the pilot gas stream?

YES

Is the ceramic insulator surrounding the electrode in good condition (not cracked or broken)?

YES

Replace Pilot Burner Assembly

6161

LIMITED WARRANTY

A. O. Smith Corporation, the warrantor, extends the following LIMITED WARRANTY to the owner of this hydronic boiler.

1. If within TEN years after initial installation of the boiler, a heat exchanger, coil or gas burner shall prove upon examination by the warrantor to be defective in material or workmanship, the warrantor, at his option will exchange or repair such part or portion. This term is reduced to FIVE years if this boiler is used for water heating purposes other than hydronic space heating. a. This warranty is extended to the owner for all other parts or portion during the FIRST year following initial installation of this boiler. b. The warranty on the repair or replacement of the part or portion will be limited to the unexpired term of the original warranty.

3. CONDITIONS AND EXCEPTIONS This warranty shall apply only when the boiler is installed in accordance with local plumbing and building codes, ordinances and regulations, the printed instructions provided with it and good industry practices. In addition, an appropriately sized safety relief valve certified to the ASME Boiler and Pressure Vessel Code must have been installed and fresh, clean water used for filling and make-up purposes. a. This warranty shall apply only when the boiler is:

(1 ) used at temperatures not exceeding the maximum setting of its operative and/or high limit control; (2 ) used at water pressure not exceeding the working pressure shown on the boiler; (3 ) used when filled with potable water, free to circulate at all times and with the heat exchanger(s) and coil(s) free of damaging scale

deposits; (4 ) in a non-corrosive and non-contaminated atmosphere; (5 ) owned by the original purchaser; (6) in it's original installation location; (7 ) is sized in accordance with proper sizing techniques for commercial boilers; (8 ) bearing a rating plate which has not been altered, defaced or removed except as required by the warrantor; (9 ) fired at the factory rated input using the fuel stated on the rating plate;

(10) maintained in accordance with the instructions printed in the manual included with the boiler;

(11) in the United States, its territories or possessions, and Canada; (12) with an intermittent circulating action and with the pump and burner operating together. (13) in an indoor installation only.

b. Any accident to the boiler, any misuse, abuse (including freezing) or alteration of it, any operation of it in a modified form, or any attempt to repair

leaks in the coil or heat exchanger will void this warranty.

4. SERVICE AND REPAIR EXPENSE Under this limited warranty the warrantor will provide only a replacement part. The owner is responsible for all other costs. Such costs may include but are not limited to: a. Labor charges for service, removal, repair or reinstallation of the component part; b. Shipping, delivery, handling, and administrative charges for forwarding the replacement part from the nearest distributor and returning the

claimed defective part to such distributor.

c. All cost necessary or incidental for any materials and/or permits required for installation of the replacement.

5. LIMITATION ON IMPLIED WARRANTIES Implied warranties, including any warranty of merchantability imposed on the sale of this boiler under state law are limited to one (1) year duration for the boiler or any of its parts. Some states do not allow limitations on how long an implied warranty lasts, so the above limitation may not apply to you.

6. CLAIM PROCEDURE Any claim under this warranty should be initiated with the dealer who sold the boiler, or with any other dealer handling the warrantor’s products. If this is not practicable, the owner should contact:

a. The warrantor will only honor replacement with identical or similar parts thereof which are manufactured or distributed by the warrantor. b. Dealer replacements are made subject to in-warranty validation by warrantor.

7. DISCLAIMERS NO OTHER EXPRESS WARRANTY HAS BEEN OR WILL BE MADE IN BEHALF OF THE WARRANTOR WITH RESPECT TO THE MERCHANT ABILITY OF THE BOILER OR THE INST ALLA TION, OPERATION, REP AIR OR REPLACEMENT OF THE BOILER. THE WARRANTOR SHALL NOT BE RESPONSIBLE FOR WA TER DAMAGE, LOSS OF USE OF THE UNIT , INCONVENIENCE, LOSS OR DAMAGE TO PERSONAL PROPERTY , OR OTHER CONSEQUENTIAL DAMAGE. THE WARRANTOR SHALL NOT BE LIABLE BY VIRTUE OF THIS WARRANTY OR OTHERWISE FOR DAMAGE TO ANY PERSONS OR PROPERTY , WHETHER DIRECT OR INDIRECT, AND WHETHER ARISING IN CONTRACT OR TORT. a. Some states or provinces do not allow the exclusion or limitation of the incidental or consequential damage, so the above limitations or exclusions

may not apply to you.

b. This warranty gives you specific legal rights, and you may also have other rights which vary from state to state.

Fill in the following for your own reference. Keep it. Registration is not a condition of warranty. The model and serial number are found on the boiler’s rating plate.

Owner___________________________________________________________________________________________________________________ Installation Address________________________________________________________________________________________________________ City and State/Province _________________________________________________________Postal/Zip Code_______________________________ Date Installed _________________________________ Model No. ___________________________ Serial No.________________________ Dealer’s Name ____________________________________________________________________ Phone No._______________________________ Dealer’s Address__________________________________________________________________________________________________________

U. S. Customers Canadian Customers A. O. Smith Corporation A. O. Smith Enterprises Ltd. 5621 West 115th Street P. O. Box, 310 - 768 Erie Street Alsip, IL 60803 Stratford, Ontario N5A 6T3 Telephone: 1-800-323-2636 Telephone: 1-800-265-8520

FILL IN DATA AND KEEP FOR FUTURE REFERENCE

6262

6363

REPLACEMENT PARTS

5621 W. 115TH STREET, ALSIP, IL 60803

PHONE: 1-800-433-2545 FAX: 1-800-433-2515

E-MAIL: parts@hotwater .com • www.hotwater.com

6464

A.O. Smith HW-300, HW-520, HWB-610, HWB-420, HW-420 User Manual

Specifications and Main Features

Frequently Asked Questions

User Manual