A.O. Smith BL-80, BL-100 Installation Manual

Instruction Manual

ULTRA LOW NOX COMMERCIAL GAS WATER HEATERS

500 Tennessee Waltz Parkway

Ashland City, TN 37015

Low Lead Content

WARNING: If the information in these instructions 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 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.

MODELS BL-100 Series 100

INSTALLATION - OPERATION - SERVICE - MAINTENANCE - LIMITED WARRANTY

Read and understand this instruction manual and the safety messages herein before installing, operating or servicing this water heater.

Failure to follow these instructions and safety messages could result in death or serious injury.

This manual must remain with the water heater.

• For Your Safety •

AN ODORANT IS ADDED TO THE GAS USED

BY THIS WATER HEATER.

place these instructions adjacent to heater and notify owner to keep for future reference.

Keep this manual in the pocket on heater for future reference whenever maintenance adjustment or service is required.

PRINTED 1112	1	324258-000

Table Of Contents

SAFE INSTALLATION, USE AND SERVICE......................	3
Approvals.......................................................................	3
GENERAL SAFETY INFORMATION..................................	4
INTRODUCTION.................................................................	5
Abbreviations Used......................................................	5
Qualified Installer or Service Agency...........................	5
Preparing for the New Installation................................	5
INSTALLATION CONSIDERATIONS..............................	6-9
Rough In Dimensions...................................................	6
Thermometers..............................................................	7
Facts to Consider About Location................................	7
High Altitude.................................................................	8
Clearances...................................................................	8
Insulation Blankets.......................................................	9
Hard Water...................................................................	9
Circulation Pumps........................................................	9
Installation Requirements...................................	10
Gas Supply Systems..................................................	10
Gas Pressure Requirements......................................	10
Supply Gas Regulator................................................	10
Mixing Valves.............................................................	10
Water Piping..............................................................	11
Closed Water Systems..............................................	11
Thermal Expansion....................................................	11
Temperature - Pressure Relief Valve.........................	11
Filling the Water Heater.............................................	12
Air Requirements.......................................................	12
Unconfined Space......................................................	13
Confined Space.........................................................	13
Fresh Air Openings for Confined Spaces...................	13
Outdoor Air Through Two Openings..........................	13
Outdoor Air Through One Opening............................	13

Outdoor Air Through Two Horizontal Ducts...............	14
Outdoor Air Through Two Vertical Ducts....................	14
Air From Other Indoor Spaces...................................	14
Venting.......................................................................	14
Gas Piping.................................................................	16
Sediment Traps..........................................................	17
LIGHTING & OPERATING INSTRUCTIONS....................	18
TEMPERATURE REGULATION.......................................	19
FOR YOUR INFORMATION.............................................	19
Start Up Conditions....................................................	19
Operational Conditions..............................................	20
PERIODIC MAINTENANCE..............................................	21
Venting System Inspection.........................................	21
Burner Inspection.......................................................	21
Burner Cleaning.........................................................	21
Housekeeping............................................................	21
Anode Rod Inspection................................................	22
Temperature-Pressure Relief Valve Test....................	22
Recommended Procedure for Periodic
Removal of Lime Deposits from Tank
TYPE Commercial Water Heaters........................	22
Deliming Solvents......................................................	23
Tank Cleanout Procedure..........................................	23
Deliming Using Flo-Jug Method.................................	23
Draining and Flushing................................................	24
Service.......................................................................	24
LEAKAGE CHECKPOINTS..............................................	25
TROUBLESHOOTING GUIDELINES...............................	26
Water Piping Diagrams.......................................	27-32
Notes..............................................................................	33
WARRANTY......................................................................	35

2

Safe Installation, Use and Service

The proper installation, use and servicing of this water heater is extremely important to your safety and the safety of others.

Many safety-related messages and instructions have been provided in this manual and on your own water heater to warn you and others of a potential injury hazard. Read and obey all safety messages and instructions throughout this manual. It is very important that the meaning of each safety message is understood by you and others who install, use, or service this water heater.

This is the safety alert symbol. It is used to alert you to potential personal injury hazards. Obey all safety messages that follow this symbol to avoid possible injury or death.

DANGER indicates an imminently

DANGER hazardous situation which, if not avoided, will result in injury or death.

WARNING indicates a potentially hazardous

WARNING situation which, if not avoided, could result in injury or death.

CAUTION indicates a potentially hazardous

CAUTION situation which, if not avoided, could result in minor or moderate injury.

CAUTION used without the safety alert CAUTION symbol indicates a potentially hazardous

situation which, if not avoided, could result in property damage.

All safety messages will generally tell you about the type of hazard, what can happen if you do not follow the safety message, and how to avoid the risk of injury.

The California Safe Drinking Water and Toxic Enforcement Act requires the Governor of California to publish a list of substances known to the State of California to cause cancer, birth defects, or other reproductive harm, and requires businesses to warn of potential exposure to such substances.

WARNING: This product contains a chemical known to the State of California to cause cancer, birth defects, or other reproductive harm. This appliance can cause low level exposure to some of the substances listed in the Act.

APPROVALS

Low Lead Content

3

general safety INFORMATION

4

Introduction

Thank You for purchasing this water heater. Properly installed and maintained, it should give you years of trouble free service.

Abbreviations Used

Abbreviations Found In This Instruction Manual:

•UL - Underwriters Laboratories Inc.

•ANSI - American National Standards Institute

•NFPA - National Fire Protection Association

•ASME - American Society of Mechanical Engineers

•AHRI - Air-Conditioning, Heating and Refrigeration Institute

•CAN - Canada

•EPACT - Energy Policy Act

•CSA - Canadian Standards Association

This gas-fired water heater is design certified by Underwriters Laboratories Inc. under American National Standard/CSA Standard for Gas Water Heaters ANSI Z21.10.3 • CSA 4.3 (current edition).

Qualified Installer or Service Agency

Installation and service of this water heater requires ability equivalent to that of a Qualified Agency (as defined by ANSI below) in the field involved. Installation skills such as plumbing, air supply, venting, gas supply and electrical supply are required in addition to electrical testing skills when performing service.

ANSI Z223.1 2006 Sec. 3.3.83: “Qualified Agency” - “Any individual, firm, corporation or company that either in person or through a representative is engaged in and is responsible for (a) the installation, testing or replacement of gas piping or (b) the connection, installation, testing, repair or servicing of appliances and equipment; that is experienced in such work; that is familiar with all precautions required; and that has complied with all the requirements of the authority having jurisdiction.”

If you are not qualified (as defined by ANSI above) and licensed or certified as required by the authority having jurisdiction to perform a given task do not attempt to perform any of the procedures described in this manual. If you do not understand the instructions given in this manual do not attempt to perform any procedures outlined in this manual.

Preparing For The Installation

1.Read the “General Safety” section, page 4 of this manual first and then the entire manual carefully. If you don’t follow the safety rules, the water heater will not operate properly.

It could cause DEATH, SERIOUS BODILY INJURY AND/OR

PROPERTY DAMAGE.

This manual contains instructions for the installation, operation, and maintenance of the gas-fired water heater. It also contains warnings throughout the manual that you must read and be aware of. All warnings and all instructions are essential to the proper operation of the water heater and your safety. Since we cannot put everything on the first few pages,

READ THE ENTIRE MANUAL BEFORE ATTEMPTING TO INSTALL OR OPERATE THE WATER HEATER.

2.The installation must conform with these instructions and the local code authority having jurisdiction. In the absence of local codes, the installation must comply with the current editions of the National Fuel Gas Code, ANSI Z223.1/ NFPA 54 or CAN/CSA-B149.1 the Natural Gas and Propane Installation Code. All documents are available from the Canadian Standards Association, 8501 East Pleasant Valley Road, Cleveland, OH 44131. NFPA documents are also available from the National Fire Protection Association, 1 Batterymarch Park, Quincy, MA 02269.

3.If after reading this manual you have any questions or do not understand any portion of the instructions, call the local gas utility or the manufacturer whose name appears on the rating plate.

4.Carefully plan the place where you are going to put the water heater. Correct combustion, vent action, and vent pipe installation are very important in preventing death from possible carbon monoxide poisoning and fires, see Figures

3 and 7.

Examine the location to ensure the water heater complies with the “Locating the New Water Heater” section in this manual.

5.For California installation this water heater must be braced, anchored, or strapped to avoid falling or moving during an earthquake. See instructions for correct installation procedures. Instructions may be obtained from California Office of the State Architect, 400 P Street, Sacramento,

CA 95814.

6.Massachusetts Code requires this water heater to be installed in accordance with Massachusetts 248-CMR 2.00: State Plumbing Code and 248-CMR 5.00.

7.Complies with SCAQMD rule #1146.2 and districts having equivalent NOx requirements.

5

Installation considerationS

ROUGH IN DIMENSIONS

K
HOT WATER		K	TOP VIEW
OUTLET	F
		COLD WATER
		INLET	H
J
			TEMPERATURE
			AND PRESSURE
DRAIN			RELIEF VALVE
VALVE		D	HOT	COLD	C
			C
		B

A

DRAIN VALVE

L

GAS INLET

E

M	INSTALL IN ACCORDANCE WITH LOCAL CODES

FIGURE 1.

TABLE 1.

DIMENSIONS

Model			Units		A		B		C					D		E		F		G		H		J		K		L			M
BL-100			Inches		70 1/2		66 1/2		30 15/16				27 3/4		15 3/16		4		15 3/4		16		1 1/4		1 1/4		1/2			11 15/16
Natural			CM		179.07		168.9		78.59				70.5		38.6		10.2		40.0		40.6		3.2		NPT		NPT			30.3
RECOVERY RATINGS
	INPUT RATE						Recovery in US Gallons/hr or Liters/hr at Indicated Temperature Rise in Fahrenheit or Celsius
BL-100	75,100		BTU/H		°F		30		40		50			60		70		80		90		100		110		120		130			140
					GPH		246		184		148			123		105		92		82		74		67		62		57			53
	22		KW		°C		17		22		28			33		39		44		50		56		61		67		72			78
					LPH		927		695		557			462		397		347		309		278		252		233		214			198

Recovery ratings based on 81% thermal efficiency.

6

THERMOMETERS (Not Supplied)

Thermometers should be obtained and field installed.

Thermometers are installed in the system as a means of detecting the temperature of the outlet water supply.

This Water Heater has been design certified as complying with ANSI Z21.10.3-CSA 4.3 current edition for water heaters and is considered suitable for:

Water (Potable) Heating and Space Heating: All models are considered suitable for water (potable) heating and space heating.

HOTTER WATER CAN SCALD:

Water heaters are intended to produce hot water. Water heated to a temperature which will satisfy space heating, clothes washing, dish washing, and other sanitizing needs can scald and permanently injure you upon contact. Some people are more likely to be permanently injured by hot water than others. These include the elderly, children, the infirm, or physically/mentally handicapped. If anyone using hot water in your home fits into one of these groups or if there is a local code requiring a certain temperature water at the hot water tap, then you must take special precautions. In addition to using the lowest possible temperature setting that satisfies your hot water needs, a means such as a *Mixing Valve should be used at the hot water taps used by these people or at the water heater. Mixing valves are available at plumbing supply or hardware stores. Consult a qualified installer or service agency. Follow mixing valve manufacturer’s instructions for installation of valves. Before changing the factory setting on the thermostat, read the “Temperature Regulation” section in this manual, see Figures 17 and 18.

Facts to Consider About the Location

Carefully choose an indoor location for the new water heater, because the placement is a very important consideration for the safety of the occupants in the building and for the most economical use of the water heater. This water heater is not for use in manufactured (mobile) homes or outdoor installation.

Whether replacing an old water heater or putting the water heater in a new location, the following critical points must be observed:

1.Select a location indoors as close as practical to the gas vent or chimney to which the water heater vent is going to be connected, and as centralized with the water piping system as possible.

2.Selected location must provide adequate clearances for servicing and proper operation of the water heater.

Installationofwaterheatermustbeaccomplishedinsuchamannerthat ifthetankoranyconnectionsshouldleak,flow willnotcausedamageto

the structure. For this reason, it is not advisable to install water heater in an attic or upper floor. When such locations cannot be avoided, a suitable metal drain pan should be installed under the water heater. Metal Drain pans are available at your local hardware store. Such a metal drain pan must have a minimum length and width of at least 2” (51 mm) greater than water heater dimensions and must be piped

to an adequate drain. The pan must not restrict combustion air flow.

Water heater life depends upon water quality, water pressure and the environment in which the water heater is installed. Water heaters are sometimes installed in locations where leakage may result in property damage, even with the use of a drain pan piped to a drain. However, unanticipateddamagecanbereducedorpreventedbyaleakdetector or water shut-off device used in conjunction with a piped drain pan. These devices are available from some plumbing supply wholesalers and retailers, and detect and react to leakage in various ways:

•Sensors mounted in the drain pan that trigger an alarm or turn off the incoming water to the water heater when leakage is detected.

•Sensors mounted in the drain pan that turn off the water supply to the entire home when water is detected in the drain pan.

•Water supply shut-off devices that activate based on the water pressure differential between the cold water and hot water pipes connected to the water heater.

•Devices that will turn off the gas supply to a gas water heater while at the same time shutting off its water supply.

INSTALLATIONS IN AREAS WHERE FLAMMABLE LIQUIDS

(VAPORS)ARELIKELYTOBEPRESENTORSTORED(GARAGES, STORAGEAND UTILITYAREAS, ETC.): Flammable liquids (such as gasoline, solvents, propane [LP or butane, etc.] and other substances suchasadhesives,etc.)emitflammable vaporswhichcanbeignitedby a gas water heater’s pilot light or main burner. The resulting flashback andfire cancausedeathorseriousburnstoanyoneinthearea,aswell aspropertydamage.Ifinstallationinsuchareasisyouronlyoption,then installationmustbeaccomplishedinawaythatthepilotflame andmain burner flame are elevated from floor at least 18 inches. While this may reduce chances of flammable vapors, from a floor spill being ignited, gasoline and other flammable substances should never be stored or

7

used in the same room or area containing a gas water heater or other openflameorsparkproducingappliance.NOTE:Flammablevaporsmay bedrawnbyaircurrentsfromotherareasofthestructuretotheappliance.

Also, the water heater must be located and/or protected so it is not subject to physical damage by a moving vehicle.

Thiswaterheatermustnotbeinstalleddirectlyoncarpeting. Carpeting must be protected by metal or wood panel beneath the water heater extendingbeyondthefullwidthanddepthofthewaterheaterbyatleast 3” (76.2 mm) in any direction, or if the water heater is installed in an alcove or closet, the entire floor must be covered by the panel. Failure to heed this warning may result in a fire hazard.

high altitude

Water heaters covered in this manual have been tested and approved for installation at elevations up to 7,700 feet (2,347 m) above sea level. For installation above 7,700 feet (2,347 m), the water heater’s Btu input should be reduced at the rate of 4 percent for each 1,000 feet (305 m) above sea level which requires replacement of the burner orifice in accordance with the National Fuel Gas Code ANSI Z223.1/ NFPA 54 or the Natural Gas and Propane Installation Code CAN/ CSA B149.1. Contact your local gas supplier for further information.

Failure to replace the standard orifice with the proper high altitude orifice when installed at elevations above 7,700 feet (2,347 m) could result in improper and inefficient operation of the water heater, producing carbon monoxide gas in excess of the safe limits. This could result in serious injury or death. Contact your local gas supplier for any specific changes that may be required in your area.

Clearances

Minimum clearances between the water heater and combustible construction are 0 inch at the sides and rear, 4” (102 mm) at the front, and 6” (153 mm) from the vent pipe. Clearance from the top of the jacket is 12” (305 mm) on most models.

FIGURE 2.

A gas water heater cannot operate properly without the correct amount of air for combustion. Do not install in a confined area such as a closet, unless you provide air as shown in the “Locating The New Water Heater” section. Never obstruct the flow of ventilation air. If you have any doubts or questions at all, call your gas supplier. Failure to provide the proper amount of combustion air can result in a fire or explosion and cause death, serious bodily injury, or property damage.

FIGURE 3.

If this water heater will be used in beauty shops, barber shops, cleaning establishments, or self-service laundries with dry cleaning equipment, it is imperative that the water heater or water heaters be installed so that combustion and ventilation air be taken from outside these areas.

Propellants of aerosol sprays and volatile compounds, (cleaners, chlorine based chemicals, refrigerants, etc.) in addition to being highly flammable in many cases, will also change to corrosive hydrochloric acid when exposed to the combustion products of the water heater. The results can be hazardous, and also cause product failure.

8

INSULATION BLANKETS

Breathing Hazard - Carbon Monoxide Gas

Do not obstruct water heater air intake

with insulating blanket.

Gas and carbon monoxide detectors

are available.

Install water heater in accordance with

the instruction manual.

Breathing carbon monoxide can cause brain damage or death. Always read and understand instruction manual.

Insulation blankets are available to the general public for external use on gas water heaters but are not necessary with these products. The purpose of an insulation blanket is to reduce the standby heat loss encountered with storage tank heaters. The water heaters covered by this manual meet or exceed the Energy Policy Act standards with respect to insulation and standby heat loss requirements, making an insulation blanket unnecessary.

Should you choose to apply an insulation blanket to this heater, you should follow these instructions. See the Features and Components section of this manual for identification of components mentioned below. Failure to follow these instructions can restrict the air flow required for proper combustion, potentially resulting in fire, asphyxiation, serious personal injury or death.

•Do not apply insulation to the top of the water heater, as this will interfere with safe operation of the draft hood.

•Do not cover the thermostat or the TemperaturePressure Relief Valve.

•Do not allow the insulation to come within 2 inches (5 cm) of the floor to prevent blockage of combustion air flow to the burner.

•Do not cover the instruction manual. Keep it on the side of the water heater or nearby for future reference.

•Do obtain new warning and instruction labels from the manufacturer for placement on the blanket directly over the existing labels.

•Do inspect the insulation blanket frequently to make certain it does not sag, thereby obstructing the combustion air flow.

Hard Water

Where hard water conditions exist, water softening or the threshold type of water treatment is recommended. This will protect the dishwashers, coffee urns, water heaters, water piping and other equipment. See the Maintenance Section in this manual for sediment and lime scale removal procedures.

Circulation Pumps

A circulating pump is used when a system requires a circulating loop or there is a storage tank used in conjunction with the water heater. See Water Piping Diagrams in this manual for installation location of circulating pumps.

See the Circulation Pump Wiring Diagrams below for electrical hookup information. Install in accordance with the current edition of the National Electrical Code, NFPA 70 or the Canadian Electrical Code, CSA C22.1.

Allbronzeorstainlesssteelcirculatingpumpsarerecommended for used with commercial water heaters.

Some circulating pumps are manufactured with sealed bearings and do not require further lubrication. Some circulating pumps must be periodically oiled. Refer to the pump manufacturer’s instructions for lubrication requirements.

CIRCULATING PUMP WIRING DIAGRAM STORAGE TANK OR BUILDING RECIRCULATION

FIELD SUPPLIED TEMPERATURE CONTROL INSTALLED IN THE STORAGE TANK

OR CIRCULATING LOOP RETURN LINE

NOTE: USE SEPARATE 120 VAC POWER

SUPPLY FOR PUMP CIRCUIT. DO NOT

SHARE POWER WITH WATER HEATER AS THIS MAY CAUSE ELECTRICAL LINE NOISE AND LEAD TO ERRATIC CONTROL SYSTEM OPERATION.

L1 HOT

120 VAC	CIRC
POWER	PUMP
	MOTOR

L2 NEUTRAL

FIGURE 4.

CIRCULATING PUMP WIRING DIAGRAM

DISHWASHER LOOP WITH TOGGLE SWITCH

DISHWASHER

TOGGLE

SWITCH

NOTE: USE SEPARATE 120 VAC POWER SUPPLY FOR PUMP CIRCUIT. DO NOT SHARE POWER WITH WATER HEATER AS THIS MAY CAUSE ELECTRICAL LINE NOISE AND LEAD TO ERRATIC CONTROL SYSTEM OPERATION.

L1 HOT

120 VAC POWER

L2 NEUTRAL

FIELD SUPPLIED TEMPERATURE CONTROL INSTALLED IN THE CIRCULATING LOOP RETURN LINE

CIRC

PUMP

MOTOR

figure 5.

9

Installation requirements

GAS SUPPLY SYSTEMS

Low pressure building gas supply systems are defined as those systems that cannot under any circumstances exceed 14” W.C. (1/2 PSI Gauge). These systems do not require pressure regulation. Measurements should be taken to insure that gas pressures are stable and fall within the requirements stated on the water heater rating plate. readings should be taken with all gas burning equipment off (static pressure) and with all gas burning equipment running at maximum rate (dynamicpressure).Thegassupplypressuremustbestablewithin1.5” W.C. from static to dynamic pressure to provide good performance. Pressure drops that exceed 1.5” W.C. may cause rough starting, noisy combustionornuisanceoutages. Increasesorspikesinstaticpressure during off cycles may cause failure to ignite or in severe cases damage to appliance gas valves. If your low pressure system does not meet these requirements, the installer is responsible for the corrections.

High Pressure building supply systems use pressures that exceed 14” W.C. (1/2 PSI Gauge). These systems must use field supplied regulators to lower the gas pressure to less than 14” W.C. (1/2 PSI Gauge).Appliancesrequiregasregulatorsthatareproperlysizedforthe water heater input and deliver the rating plate specified pressures. Gas supply systems where pressure exceeds 5 PSI often require multiple regulators to achieve desired pressures. Systems in excess of 5 PSI building pressure should be designed by gas delivery professionals for best performance. Water heaters connected to gas supply systems that exceed 14” W.C. (1/2 PSI Gauge) at any time must be equipped with a gas supply regulator.

GAS PRESSURE REQUIREMENTS

Natural gas models require a minimum gas supply pressure of 4.5” W.C. (1.12 kPa). Propane gas models require a minimum gas supply pressure of 11” W.C. (2.74 kPa). The minimum supply pressure is measured while gas is flowing (dynamic pressure). The supply pressure (dynamic) should never fall below the specified minimum supply pressure.The supply pressure should be measured with all gas fired appliances connected to the common main firing at full capacity. If thesupplypressuredropsmorethan1.5”W.C.(0.37kPa)asgasbegins to flow to the water heater then the supply gas system including the gas line and/or the gas regulator may be restricted or undersized. See Supply Gas regulator section and Gas Piping section of this manual. The gas valve on all models has a maximum gas supply pressure limit of 14” W.C. (3.48 kPa) The maximum supply pressure is measured while gas is not flowing (static pressure).

SUPPLY GAS REGULATOR

The maximum allowable gas supply pressure for this water heater is 14.0 inches W.C. (3.48 kPa). Install a positive lock-up gas pressure regulator in the gas supply line if inlet gas pressure can exceed 14.0 inches W.C. (3.48 kPa) at any time. regulators must be sized/used according to manufacturer’s specifications.

If a positive lock-up regulator is required follow these instructions:

1.Positive lock-up gas pressure regulators must be rated at or above the input Btu/hr rating of the water heater they supply.

2.Positive lock-up gas pressure regulator(s) should be installed no closer than 3 feet (1 meter) and no farther than 8 feet (2.4 meters) of equivalent length from the water heater’s inlet gas connection.

3.Afterinstallingthepositivelock-upgaspressureregulator(s)aninitial nominal supply pressure setting of 7.0” W.C. while the water heater is operating is recommended and will generally provide good water heater operation. Some addition adjustment maybe required later to maintain a steady gas supply pressure.

4.When installing multiple water heaters in the same gas supply system it is recommended that individual positive lock-up gas pressure regulators be installed at each unit.

Mixing Valves

Water temperature over 125°F (52°C) can cause severe burns instantly resulting in severe injury or death.

Children, the elderly and the physically or mentally disabled are at highest risk for scald injury.

Feel water before bathing or showering.

Temperature limiting devices such as mixing valves must be installed when required by codes and to ensure safe temperatures at fixtures.

Water heated to a temperature which will satisfy clothes washing, dish washing, and other sanitizing needs can scald and cause permanent injury upon contact. Short repeated heating cycles caused by small hot water uses can cause temperatures at the point of use to exceed the water heater’s temperature setting by up to 20°F (11°C).

Some people are more likely to be permanently injured by hot water than others. These include the elderly, children, the infirm and the physically/mentally disabled. Table 2 shows the approximate time- to-burn relationship for normal adult skin. If anyone using hot water provided by the water heater being installed fits into one of these groups or if there is a local code or state law requiring a certain water temperatureatthepointofuse,thenspecialprecautionsmustbetaken.

In addition to using the lowest possible temperature setting that satisfies demand of the application a Mixing Valve should be installed at the water heater or at hot water taps to further reduce system water temperature. See Figure 6.

Mixing valves are available at plumbing supply stores. Consult a Qualified Installer or Service Agency. Follow mixing valve manufacturer’s instructions for installation of the valves.

Table 2.

Water		Time for			Time for Permanent Burns
		1st Degree Burn				2nd & 3rd Degree
Temperature °F
		(Less Severe Burns)			(Most Severe Burns)
110		(normal shower temp.)
116		(pain threshold)
116		35 minutes					45 minutes
122		1 minute					5 minutes
131		5 seconds					25 seconds
140		2 seconds					5 seconds
149		1 second					2 seconds
154		instantaneous					1 second
(U.S. Government Memorandum, C.P.S.C., Peter L.Armstrong, Sept. 15,1978)
			HOT WATER
			OUTLET
				12” TO 15”
	TEMPERED WATER			(30-38 cm)
		OUTLET
COLD					CHECK
WATER					VALVE
INLET				MIXING
			CHECK
				VALVE
			VALVE

TO TANK

INLET

Figure 6.

10

Water Piping

WATER (POTABLE) HEATING AND SPACE HEATING

This water heater shall not be connected to any heating systems or component(s) used with a non-potable water heating appliance.

All piping components connected to this unit for space heating applications shall be suitable for use with potable water.

Toxic chemicals, such as those used for boiler treatment shall not be introduced into this system.

When the system requires water for space heating at temperatures higher than required for domestic water purposes, a mixing valve must be installed. Please refer to Figure 2 for suggested piping arrangement.

These water heaters cannot be used in space heating applications only.

Closed Water Systems

Water supply systems may, because of code requirements or such conditions as high line pressure, among others, have installed devices such as pressure reducing valves, check valves, and back flow preventers. Devices such as these cause the water system to be a closed system.

Thermal Expansion

As water is heated, it expands (thermal expansion). In a closed system the volume of water will grow when it is heated. As the volume of water grows there will be a corresponding increase in water pressure due to thermal expansion. Thermal expansion can cause premature tank failure (leakage). This type of failure is not covered under the limited warranty. Thermal expansion can also cause intermittent Temperature-Pressure Relief Valve operation: water discharged from the valve due to excessive pressure build up. This condition is not covered under the limited warranty. The Temperature-Pressure Relief Valve is not intended for the constant relief of thermal expansion.

A properly sized thermal expansion tank must be installed on all closed systems to control the harmful effects of thermal expansion. Contact a local plumbing service agency to have a thermal expansion tank installed.

FIGURE 7.

NOTE: To protect against untimely corrosion of hot and cold water fittings, it is strongly recommended that di-electric unions or couplings be installed on this water heater when connected to copper pipe.

Figure 7 shows the typical attachment of the water piping to the water heater. The water heater is equipped with 1.25” NPT threaded nipple water connections.

Temperature-Pressure Relief Valve

Explosion Hazard

Temperature-Pressure Relief Valve must comply with ANSI Z21.22CSA 4.4 and ASME code.

Properly sized temperaturepressure relief valve must be installed in opening provided.

Can result in overheating and excessive tank pressure.

Can cause serious injury or death.

This water heater is provided with a properly rated/sized and certified combination Temperature-Pressure Relief Valve (T&P valve) by the manufacturer. The valve is certified by a nationally recognized testing laboratory that maintains periodic inspection of production of listed equipment of materials as meeting the requirements for Relief Valves for Hot Water Supply Systems, ANSI Z21.22 • CSA 4.4, and the code requirements of ASME.

If replaced, the new T&P valve must meet the requirements of local codes, but not less than a combination Temperature-Pressure Relief Valve rated/sized and certified as indicated in the above paragraph. The new valve must be marked with a maximum set pressure not to exceed the marked hydrostatic working pressure of the water heater (150 psi = 1,035 kPa) and a discharge capacity not less than the water heater Btu/hr or kW input rate as shown on the water heater’s model rating label.

11