John Wood 100 Series User manual

1
Instruction Manual
PRINTED 1113 325732-001
PLACE THESE INSTRUCTIONS ADJACENT TO HEATER AND NOTIFY OWNER TO KEEP FOR FUTURE REFERENCE.
COMMERCIAL ELECTRIC WATER HEATERS
Thank you for buying this energy efcient water heater.
We appreciate your condence in our products.
MODELS (A)JWES-50/80/119 SERIES 100 &
(A)JWEI-50/80/119 SERIES 100
INSTALLATION - OPERATION - SERVICE
MAINTENANCE - LIMITED WARRANTY
(OPTIONAL)
599 Hill Street West Fergus,
ON Canada N1M 2X1

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.
IMPORTANT DEFINITIONS
•  
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, electrical supply are required in addition to electrical testing skills when
performing service.
•  
“Qualied Agency” - “Any individual, rm, 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.”
DANGER
WARNING
CAUTION
DANGER indicates an imminently hazardous
situation which, if not avoided, will result in
death or injury.
WARNING indicates a potentially hazardous
situation which, if not avoided, could result
in death or injury.
CAUTION indicates a potentially hazardous
situation which, if not avoided, could result
in minor or moderate injury.
CAUTION used without the safety alert
symbol indicates a potentially hazardous
situation which, if not avoided, could result
in property damage.
CAUTION
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.

3
GENERAL SAFETY INFORMATION
When servicing this unit, verify the power to the unit is turned off prior to opening the control cabinet door.
PRECAUTIONS
DO NOT USE THIS WATER HEATER IF ANY PART HAS BEEN
UNDER WATER. Immediately call a qualied service technician
to inspect the water heater and to replace any part of the control
system which has been under water.
If the unit is exposed to the following, do not operate heater until
all corrective steps have been made by a qualied service agency:
1. External re.
2. Damage.
3. Firing without water.
GROUNDING INSTRUCTIONS
This water heater must be grounded in accordance with the
National Electrical Code, NFPA 70 or the Canadian Electrical
Code CSA C22.1 and/or local codes. These must be followed
in all cases. Failure to ground this water heater properly may
also cause erratic control system operation on ELECTRONIC
CONTROL models.
This water heater must be connected to a grounded metal, permanent
wiring system; or an equipment grounding conductor must be run with
the circuit conductors and connected to the equipment grounding
terminal or lead on the water heater.
HYDROGEN GAS (FLAMMABLE)
Hydrogen gas can be produced in a hot water system served by this
heater that has not been used for a long period of time (generally two
weeks or more). Hydrogen gas is extremely ammable.
To reduce the
risk of injury under these conditions, it is recommended that the hot water
faucet be opened for several minutes at the kitchen sink before using any
electrical appliance connected to the hot water system. If hydrogen is present
there will probably be an unusual sound such as air escaping through the pipe
as the water begins to ow.
THERE SHOULD BE NO SMOKING OR
OPEN FLAME NEAR THE FAUCET AT THE TIME IT IS OPEN.

4
Thank You for purchasing this water heater. Properly installed and
maintained, it should give you years of trouble free service.
Abbreviations Found In This Instruction Manual:
• AHRI - Air Condition, Heating and Refrigeration Institute
• ANSI - American National Standards Institute
• ASME - American Society of Mechanical Engineers
• NEC - National Electrical Code
• NFPA - National Fire Protection Association
• UL - Underwriters Laboratory
• CSA - Canadian Standards Association
PREPARING FOR THE INSTALLATION
1. Read the “General Safety Information” section of this manual rst and
then the entire manual carefully. If you don’t follow the safety rules, the
water heater may not operate safely. It could cause DEATH, SERIOUS
BODILY INJURY AND/OR PROPERTY DAMAGE.
This manual contains instructions for the installation, operation,
and maintenance of the electric 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. READ
THE ENTIRE MANUAL BEFORE ATTEMPTING TO INSTALL
OR OPERATE THE WATER HEATER.
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 THAT ALL
WATER PIPING AND THE ELECTRICAL WIRING BE INSTALLED
AND CONNECTED AS SHOWN IN THE DIAGRAMS.
Particular attention should be given to the installation of
thermometers at the locations indicated in the diagrams as these
are necessary for checking the operation of the heater.
Be sure to turn off power when working on or near the electrical
system of the heater. Never touch electrical components with
wet hands or when standing in water. When replacing fuses
always use the correct size for the circuit. see page 13.
The principal components of the heater are identied on pages
7 & 8. The model and rating plate on page 6 interprets certain
markings into useful information. Both of these references
should be used to identify the heater, its components and
optional equipment.
2. The installation must conform with these instructions and the
local code authority having jurisdiction and the requirements of
the power company. In the absence of local codes, the installation
must comply with the current editions of the National Electrical
Code, NFPA 70 or the Canadian Electrical Code CSA C22.1.
The National Electrical Code may be ordered from: National Fire
Protection Association, 1 Batterymarch Park, Quincy, MA 02269.
The Canadian Electrical Code is available from the Canadian
Standards Association, 8501 East Pleasant Valley Road,
Cleveland, OH 44131.
3. If after reading this manual you have any questions or do not
understand any portion of the instructions, call the toll free number
listed on the back cover of this manual for technical assistance.
A sample rating plate is shown on page 6 of this manual. In order
to expedite your request, please have full model and serial number
available for the technician.
4. Carefully plan your intended placement of the water heater.
Examine the location to ensure the water heater complies with
the “Locating the New Water Heater” section in this manual.
Installation and service of this water heater requires ability equivalent
to that of a licensed tradesman or a qualied agency (page 2) in the
eld involved. Plumbing and electrical work are required.
INTRODUCTION
SAFE INSTALLATION, USE AND SERVICE..................................... 2
GENERAL SAFETY INFORMATION ................................................. 3
TABLE OF CONTENTS ..................................................................... 4
INTRODUCTION ............................................................................... 4
Preparing for the New Installation .............................................4
DIMENSIONS AND CAPACITIES DATA ...........................................5
APPROVALS .....................................................................................6
FEATURES AND COMPONENTS .................................................7-8
LOCATING THE NEW WATER HEATER .......................................... 9
INSTALLATION ...............................................................................10
Required Ability ........................................................................ 10
General .................................................................................... 10
Mixing Valve Usage ................................................................. 10
Chemical Vapor Corrosion ....................................................... 10
Circulating Pump ..................................................................... 10
Insulation Blankets ..................................................................10
Temperature-Pressure Relief Valve .................................... 10-11
Water Line Connection ............................................................ 11
Closed Water System .............................................................. 11
Thermal Expansion .................................................................. 11
ELECTRICAL ..................................................................................12
OPERATION .................................................................................... 19
General .................................................................................... 19
Filling the Water Heater ........................................................... 19
Start Up ...................................................................................19
Draining the Water Heater ....................................................... 19
TEMPERATURE REGULATION .....................................................20
High Temperature Devices ...................................................... 20
Thermostat Controls ................................................................ 20
Thermostat Settings – Surface Mount Control Models ............ 20
Thermostat Settings – Electronic Control Models ................... 21
ELECTRONIC CONTROL MODELS OPERATION ......................... 21
Control System Features ......................................................... 21
Control System Navigation ...................................................... 21
Desktop Screen ..................................................................21-23
Temperatures Menu ............................................................23-24
Temperature Settings ..............................................................24
Heater Status Menu .................................................................25
Economy Mode Setup Menu ..............................................25-26
Economy Mode Settings .....................................................26-28
Alarm Output Setup Menu ....................................................... 29
Display Settings Menu ............................................................. 29
Heater Information Menu ....................................................29-30
Current Fault / Alert Menu ....................................................... 30
Fault Occurrence Menu ........................................................... 30
Restore Factory Defaults Menu ..........................................30-31
MAINTENANCE .............................................................................. 31
General ...............................................................................31-32
Flushing ................................................................................... 32
Sediment Removal .................................................................. 32
Water and Lime Scale Removal .........................................32-33
TROUBLESHOOTING CHECKLIST ............................................... 34
Not Enough or No Water ......................................................... 34
Water Heater Makes Strange Sounds ..................................... 34
If You Cannot Identify or Correct the Source of Malfunction ............ 17
Leakage Checkpoints .............................................................. 35
PIPING DIAGRAMS ...................................................................36-47
MANIFOLD DIAGRAMS .................................................................. 48
WARRANTY .................................................................................... 51
TABLE OF CONTENTS

5
DIMENSIONS AND CAPACITIES DATA
Model Number Tank Capacity in Gallons (Liters) A - Inches (mm) B - Inches (mm) C - Inches (mm) Inlet/Outlet
(A)JWES or I-50 50 (189.3) 55 3/4 (1416) 21 3/4 (552) 27 (685) 1 1/4
(A)JWES or I-80 80 (302.8) 60 1/4 (1350) 25 1/2 (648) 31 (787) 1 1/4
(A)JWES or I-119 119 (450.5) 62 1/4 (1581) 29 1/2 (749) 35 (889) 1 1/4
Table 1.
RECOVERY RATE IN GALLONS PER HOUR*
Temperature Rise °F
Standard
KW Input
BTU/
Hour 30° 40° 50° 60° 70° 80° 90° 100° 110° 120° 130° 140°
620,478 82 62 49 41 35 31 27 25 22 21 19 18
9 30,717 123 92 74 62 53 46 41 37 34 31 28 26
12 40,956 164 123 98 82 70 61 55 49 45 41 38 35
13.5 46,075 184 138 111 92 79 69 62 55 50 46 43 40
15 51,195 205 154 123 102 88 77 68 61 56 51 47 44
18 61,434 246 184 148 123 105 92 82 74 67 61 57 53
24 81,912 328 246 197 164 140 123 109 98 89 82 76 70
27 92,151 369 276 221 184 158 138 123 111 101 92 85 79
30 102,390 410 307 246 205 176 154 137 123 112 102 95 88
36 122,868 492 369 295 246 211 184 164 148 134 123 113 105
40.5 138,226 554 418 3332 277 237 208 1185 166 151 138 128 119
45 153,585 615 461 369 307 263 230 205 184 168 154 142 132
54 184,302 738 553 443 369 316 277 246 221 201 184 170 158
*Figured at 1 KW (3413 Btu) = 4.1 gallons at 100°F temperature rise.
To determine recovery rate per minute, divide recovery rate per hour by 60.
Table 2.
This instruction manual covers two different

The rst models, identied with letters “ES” in the
model no. (see ‘understand your model’ section), are
referred to as “Surface Mount Control” model. Those
models are factory equipped with surface mounted
thermostat/ECO combination controls.
The second models, identied with letter “EI” in the
model no. (see “understand your models” section),
are referred to as electronic control model, are factory
equipped with an electronic control system and
immersion-type temperature probe.
Understanding
Your Models
Model Designator:
Sample: AJWES or I-80-54-240 100
A=ASME Construction if not used
standard construction
JW= John Wood
ES= Surface Mounted Thermostats or
EI= Immersion Type Thermostats
80=Gallon (302.8 Liters) can also be
50=Gallon (189.3 Liters) or
119=Gallon (450.5 Liters)
54= kW input of unit
240=Voltage can also be
208; 277; 380; 415; 480; & 600
380/415/600 are 3 Ph Wye
100 indicates series
Figure 1

6
APPROVALS
MODEL AND RATING
All models meet
National Sanitation
Foundation NSF-5
requirements.
All models are listed
by Underwriters
Laboratories Inc.
Low Lead Content

7
FEATURES AND COMPONENTS
ELECTRONIC CONTROL MODELS
Figure 2

8
FEATURES AND COMPONENTS
SURFACE MOUNT CONTROL MODELS
Figure 3

9
FACTS TO CONSIDER ABOUT THE LOCATION
Carefully choose a location for the new water heater. 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.
Whether replacing an old water heater or putting the water heater in
a new location, the following critical points must be observed. The
water heater must be located:
• On a level surface. Shim the channel type skid base as necessary
if levelling is required.
LOCATING THE NEW WATER HEATER
• Near a oor drain. The heater should be located in an area where
leakage of the tank or connections will not result in damage to
the area adjacent to the heater or to lower oors of the structure.
• Close to the point of major hot water usage and the power supply.
• Hot water piping and branch circuit wiring should be as short
as possible.
• Insulate hot and cold water piping where heat loss and
condensation may be a problem.
• Heater construction permits installation, maintenance, and
service work to be performed through the front control panel.
• Suggested clearances from adjacent surfaces are 12 inches
on top, 30 inches in front for access to the unit.
• The heater may be installed on or against combustible surfaces.
The left side and back may be placed ush against adjacent
surfaces.
• The temperature of the space in which the water heater is installed
must not go below 32°F or above 122°F.

10
INSTALLATION
REQUIRED ABILITY
Installation and service of this water heater requires ability equivalent
to that of a qualied agency (page 2) in the eld involved. Plumbing
and electrical work is required.
GENERAL
The installation must conform with these instructions and the
local code authority having jurisdiction and the requirements of
the power company. In the absence of local codes, the installation
must comply with the current editions of the National Electrical
Code, NFPA 70 or the Canadian Electrical Code CSA C22.1.
The National Electrical Code may be ordered from: National Fire
Protection Association, 1 Batterymarch Park, Quincy, MA 02269.
The Canadian Electrical Code is available from the Canadian
Standards Association, 8501 East Pleasant Valley Road,
Cleveland, OH 44131.
To comply with NSF Standard 5 installation requirements
the bottom of the water heater must be sealed to the oor with
a silicone based sealant or elevated 6 inches above the oor.
Do NOT test electrical system before heater is lled with water, follow
the START UP procedure in the OPERATION section of this manual.
The principal components of the heater are identified in the
Features and Components illustrations on pages 7 and 8.
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 heaters are intended to produce hot water. Water heated to
a temperature which will satisfy space heating, clothes washing,
dish washing, cleaning 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 inrm, or physically/developmentally disabled. If
anyone using hot water in your home ts into one of these groups or
if there is a local code requiring a maximum water temperature at the
hot water tap, then you must take special precautions. In addition to
using the lowest possible temperature setting that satises 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 for reducing point of use temperature are
available. Consult a qualied installer or service agency. Follow all
manufacturer’s Instructions for installation of these valves. Before
changing the factory setting on the thermostat, read the “Temperature
Regulation” section in this manual.
CONTAMINATED WATER
This water heater shall not be connected to any heating
system(s) or component(s) used with a non-potable water
heating appliance.
Toxic chemicals, such as those used for boiler treatment shall not
be introduced into this system.
CIRCULATING PUMP
Field installed circulating pumps should be of all bronze
construction.
INSULATION BLANKETS
Insulation blankets are available to the general public for
external use on electric water heaters but are not necessary with
this product. The purpose of an insulation blanket is to reduce
the standby heat loss encountered with storage tank heaters.
Your water heater meets or exceeds the EPACT and ASHRAE/
IES 90.1 standards with respect to insulation and standby loss
requirements, making an insulation blanket unnecessary.
Should you choose to apply an insulation blanket to this heater,
you should follow these instructions below. Failure to follow
these instructions can result in fire, serious personal injury,
or death.
• Do not cover the temperature and pressure relief (T & P) valve
with an insulation blanket.
• 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 for placement on
the blanket directly over the existing labels.
TEMPERATURE-PRESSURE RELIEF VALVE

11
This water heater is provided with a properly rated/sized
and certified combination temperature - pressure relief 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 valve must meet the requirements of local
codes, but not less than a combination temperature and 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 plate.
For safe operation of the water heater, the temperature and
pressure relief valve must not be removed from its designated
opening nor plugged. The temperature-pressure relief valve
must be installed directly into the fitting of the water heater
designed for the relief valve. Install discharge piping so that
any discharge will exit only within 6 inches (15.2 cm) above, or
external to the structure. Do not pipe the discharge to a crawl
space. Be cer tain that no contact is made with any live electrical
part. The discharge opening must not be blocked or reduced in
size under any circumstances. Excessive length, over 30 feet
(9.14 m), or use of more than four elbows can cause restriction
and reduce the discharge capacity of the valve.
No valve or other obstruction is to be placed between the relief valve
and the tank. Do not connect discharge piping directly to the drain
unless a 6” (15.2 cm) air gap is provided. To prevent bodily injury,
hazard to life, or property damage, the relief valve must be allowed
to discharge water in adequate quantities should circumstances
demand. If the discharge pipe is not connected to a drain or other
suitable means, the water ow may cause property damage.
The Discharge Pipe:
• Shall not be smaller in size than the outlet pipe size of the
valve, or have any reducing couplings or other restrictions.
• Shall not be plugged or blocked.
• Shall not be exposed to freezing temperatures.
• Shall be of material listed for hot water distribution.
• Shall be installed so as to allow complete drainage of both
the Temperature-Pressure Relief Valve and the discharge
pipe.
• Must terminate a maximum of six inches above a oor drain
or external to the building. In cold climates, it is recommended
that the discharge pipe be terminated at an adequate drain
inside the building.
• Shall not have any valve or other obstruction between the
relief valve and the drain.
The temperature-pressure relief valve must be manually
operated at least once a year. Caution should be taken to
ensure that (1) no one is in front of or around the outlet of the
temperature-pressure relief valve discharge line, and (2) the
water manually discharged will not cause any bodily injury or
property damage because the water may be extremely hot. If
after manually operating the valve, it fails to completely reset
and continues to release water, immediately close the cold water
inlet to the water heater, follow the draining instructions in this
manual, and replace the temperature-pressure relief valve with
a properly rated/sized new one.
If you do not understand these instructions or have any
questions regarding the temperature-pressure relief valve call
the toll free number listed on the back cover of this manual for
technical assistance.
WATER LINE CONNECTIONS
This manual provides detailed piping installation diagrams (see
back section of this manual) for typical methods of application.
For the heater inlet and outlet connections, dielectric unions are
recommended. The water heater may be installed by itself, or
with a separate storage tank, on both single and two-temperature
systems. When used with a separate storage tank, the circulation
may be either by gravity or by means of a circulating pump. When
a circulating pump is used it is important to note that the ow rate
should be slow so that there will be a minimum of turbulence inside
the heater.
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.

12
ELECTRICAL
GENERAL
The installation must conform with these instructions and the local code authority having jurisdiction and the requirements of the power
company. In the absence of local codes, the installation must comply with the current editions of the National Electrical Code, NFPA 70 or
the Canadian Electrical Code CSA C22.1.
An electrical ground is required to reduce risk of electrical shock or possible electrocution. The water heater should be connected to a
separate grounded branch circuit with over-current protection and disconnect switch. The water heater should be grounded in accordance
with national and local codes.
Voltage applied to the heater should not vary more than +5% to -10% of the model and rating plate marking for satisfactory operation.
Allowable Ampacities of Insulated Conductors
Not more than three conductors in raceway, cable, or earth (directly buried), based on ambient temperature of 30°C (86°F)
+The load current rating and the overcurrent protection for these conductors shall not exceed 15 amperes for 14 AWG. 20 amperes for 12 AWG.
and 30 amperes for 10 AWG copper; or 15 amperes for 12 AWG and 25 amperes for 10 AWG aluminum and copper-clad aluminum.
*For dry locations only. See 75°C column for wet locations.
Table 3.

13
AMPERAGE TABLE/OVERCURRENT PROTECTION
The tables above provides the total connected heating element load
in amperes for branch circuit conductor and overcurrent protection
sizing. Single-phase heaters are two wire circuits. Three-phase
heaters are three wire circuits. In addition to the foregoing, a
grounded conductor is required.
The rating of the overcurrent protection must be computed on the basis
of 125% of the total connected load amperage. Where the standard
ratings and settings do not correspond with this computation, the next
higher standard rating or setting should be selected.
HEATER CIRCUITS - ELECTRONIC CONTROL MODELS
The water heater’s electrical components are pictured and identied
in Figure 2 and Figure 3 The model and rating plate illustration on
page 4 identies heater circuit ratings. The ELECTRONIC CONTROL
model has two electrical circuits:
• The control circuit, which controls the electrical power to heating
elements, referring the following control circuit diagram Figure 6
• The power circuit, which is operated by the control circuit carries
the electrical load of the heating elements. The following
describes the heater circuits and includes wiring diagrams for
Delta conguration, refer to the “WYE Conguration Insert” for
water heaters operating at 380V/400V/416V/575V. All heater
circuits are designed for 50/60 cycle alternating current.
CONTROL CIRCUIT- ELECTRONIC CONTROL MODELS
These models are equipped with an electronic control system. The
system includes a CCB (Central Control Board), an immersion
temperature probe with ECO for temperature sensing and limiting, a
UIM (User Interface Module) for user interface & information display
and element current sensors for monitoring the power circuits. Refer
to the control circuit label on the water heater for details. The CCB is
powered by a small 120V/24V transformer. The control circuit operates
on 120V supplied by a larger 100VA transformer. Standard equipment
includes control circuit fusing using two, 3 amp, class G fuses with 600
volt rating. Do not substitute fuses of a different rating.
Sequence of Operation
1. When the control is powered, the UIM should display model
information, water temperature, Operating Set Point, heating
status and operating mode.
2. If the control determines that the actual water temperature inside
the tank is below the programmed Operating Setpoint minus the (1st)
differential, a call for heat is activated.
3. After all safety checks are veried, the CCB will energize contactor
coils starting with the lower bank of heating elements (each diagonal
row of three heating elements is considered a “bank” - see Figure 2)
then energize the middle bank (if so equipped) and top bank (if so
equipped). The middle and top banks (if so equipped) are energized
according to programmed 2nd and 3rd differential set points.
4. The control remains in the heating mode until the water temperature
reaches the programmed Operating Setpoint. At this point the
contactors will be de-energized in the reverse order.
5. The control system now enters the standby operating mode
while continuing to monitor the water temperature and the state
of other system devices. If the water temperature drops below
the programmed Operating Setpoint minus the (1st) differential,
the control will automatically return to step 2 and repeat the
heating cycle.
NOTE: See the Electronic Control Models Operation section for more
detailed information on temperature settings mentioned above.
120 VAC CONTROL CIRCUIT TRANSFORMER CONNECTIONS - ELECTRONIC CONTROL MODELS
Table 4.
Table 5.
Figure 4
Figure 5

14
CCB (CENTRAL CONTROL BOARD)
CONTROL CIRCUIT DIAGRAM - ELECTRONIC CONTROL MODELS
Figure 6
WIRING DIAGRAMS

15
DIAGRAM 1.
WIRING DIAGRAMS
POWER CIRCUIT DIAGRAMS - ELECTRONIC CONTROL MODELS
The water heater’s electrical components are pictured and identied on page 7. The following describes the heater circuits and includes wiring
diagrams. All heater circuits are designed for 60/50 hertz alternating current. The water heater circuit wiring is 12 AWG, AWM, or TEW type,
rated 600 volts, 105°C. Fusing consists of three 30 amp fuses for each contactor. Fusing is an optional feature for Canadian models.
THREE ELEMENTS - SINGLE AND THREE PHASE
SIX ELEMENTS - SINGLE AND THREE PHASE

16
WIRING DIAGRAMS
NINE ELEMENT - SINGLE AND THREE PHASE
CONVERSION TO SINGLE PHASE
When the heater is shipped for connection to a three-phase electrical
service, it may be connected to a single-phase electrical service of
the same voltage by:
1. Disconnect blue wires and yellow wires from terminal L3.
2. Reconnect all blue wires to terminal L1 (with black wires).
3. Reconnect all yellow wires to terminal L2 (with red wires).
4. Connect incoming power to terminals L1 and L2.
CONVERSION TO THREE PHASE
When heater is shipped for connection to a single-phase electrical
service, it may be connected to a three-phase electrical service of
the same voltage by:
1. Disconnect blue wires from terminal L1.
2. Disconnect yellow wires from terminal L2.
3. Reconnect all blue wires and yellow wires to terminal L3.
4. Connect incoming power to terminals L1, L2, and L3.
DIAGRAM 2.

17
WIRING DIAGRAMS
POWER CIRCUIT DIAGRAMS - SURFACE MOUNT CONTROL MODELS
The water heater’s electrical components are pictured and identied on page 8. The following describes the heater circuits and includes
wiring diagrams. All heater circuits are designed for 60/50 hertz alternating current. The water heater circuit wiring is 12 AWG, AWM, or
TEW type, rated 600 volts, 105°C. Fusing consists of two 30 amp fuses for each element. Fusing is an optional feature for Canadian models.
DIAGRAM 3.

18
WIRING DIAGRAMS
CONVERSION TO SINGLE PHASE
When the heater is shipped for connection to a three-phase electrical
service, it may be connected to a single-phase electrical service of
the same voltage by:
1. Disconnect blue wires from terminal L2.
2. Connect all blue wires to terminal L1 (with black wires).
3. Disconnect all red wires from terminal L3.
4. Connect all red wires to terminal L2 (with yellow wires).
5. Connect incoming power to terminals L1 and L2.
CONVERSION TO THREE PHASE
When heater is shipped for connection to a single-phase electrical
service, it may be connected to a three-phase electrical service of
the same voltage by:
1. Disconnect blue wires from terminal L1
2. Disconnect red wires from terminal L2.
3. Connect all blue wires to terminal L2 (with yellow wires).
4. Connect red wires to terminal L3.
5. Connect incoming power to terminals L1, L2 and L3.
NINE ELEMENTS - SINGLE AND THREE PHASE
DIAGRAM 4.

19
OPERATION
GENERAL
Refer to the Features and Components section of this manual
(pages 7 & 8) for the location of components mentioned in the
instructions that follow.
NEVER turn on power to the water heater without being certain the
water heater is lled with water and a temperature and pressure
relief valve is installed in the relief valve opening.
DO NOT TEST ELECTRICAL SYSTEM BEFORE HEATER IS
FILLED WITH WATER. FOLLOW FILLING AND START-UP
INSTRUCTIONS IN OPERATION SECTION.
FILLING THE WATER HEATER
1. Turn off the electrical disconnect switch.
2. Close the water heater drain valve.
3. Open a nearby hot water faucet to permit the air in the system
to escape.
4. Fully open the cold water inlet pipe valve allowing the heater and
piping to be lled.
5. Close the hot water faucet as water starts to ow. The heater is
now ready for STARTUP and TEMPERATURE REGULATION.
INITIAL START UP
The following checks should be made by the installer when the heater
is placed into operation for the rst time.
1. Turn off the electrical disconnect switch.
2. Open the front panel, check all water and electrical connections
for tightness. Also check connections on top and side of heater.
Repair water leaks and tighten electrical connections as
necessary.
3. Depress the red manual reset button on each Thermostat/ECO
combination control (Surface Mount Control Models only).
4. Turn on the electrical disconnect switch.
5. Observe the operation of the electrical components during the rst
heating cycle. Use care as the electrical circuits are energized.
6. Close the front panel.
Temperature control and contactor operation should be checked
by allowing heater to come up to temperature and shut off
automatically. Use care as the electrical circuits are energized.
DRAINING THE WATER HEATER
It is recommended that the water heater storage tank be
drained and ushed every 6 months to reduce sediment
buildup. The water heater should be drained if being shut down
during freezing temperatures. See Features And Components
in this manual for the location of the water heater components
described below.
Burn harzard.
Hot water discharge.
Keep hands clear of drain
valve discharge.

1. Turn off the electrical supply to the water heater at the
breaker or disconnect switch.
2. Ensure the cold water inlet valve is open.
3. Open a nearby hot water faucet and let the water run until
the water is no longer hot.
4. Close the cold water inlet valve to the water heater.
5. Connect a hose to the water heater drain valve and terminate
it to an adequate drain.
6. Open the water heater drain valve and allow all the water to
drain from the storage tank.
7. Close the water heater drain valve when all water in the
storage tank has drained.
8. Close the hot water faucet opened in Step 3.
9. If the water heater is going to be shut down for an extended
period, the drain valve should be left open.

20
HIGH TEMPERATURE LIMIT CONTROLS (ECO)
Both the ELECTRONIC CONTROL and SURFACE MOUNT
CONTROL model water heaters are equipped with one or more ECO
(energy cut off) non adjustable high temperature limit control(s). An
ECO is a normally closed switch that opens (activates) on a rise
in temperature. If the ECO switch contacts open (activate) due to
abnormally high water temperatures it will lock-out and disable further
heating element operation. It is important that a qualied service
agent be contacted to determine the reason for the ECO activation
before resetting the ECO. Once the reason has been determined
and corrected the ECO(s) can be reset as follows:
Surface Mount Control Models
Surface Mount Control models have multiple surface mounted
Thermostat/ECO combination controls. One for each installed heating
element - see the Surface Mount Control wiring diagrams in this
manual. The ECO high temperature limit switch contacts on each
control will open when the tank temperature reaches approximately
200°F/93°C. If activated, the ECO reset button will be slightly extended
and stiff to the touch. When the ECO switch contacts open (activate)
voltage to ONE heating element ONLY is terminated to prevent further
heating operation of that element. Voltage may still be present at other
heating elements and they may still be heating the water.
The ECO is a manual reset switch. Should one or more ECO activate,
the tank temperature must drop below 120°F/49°C before an ECO
can be reset. To manually reset an ECO:
1. Disconnect the power supply to the water heater.
2. Allow the tank temperature to cool below 120°F/49°C.
3. Remove the front control cover from the effected control(s).
4. Press the manual reset button on each of the effected controls.
5. Once the control(s) has been reset the control cover should be
replaced prior to restoring power to the water heater.
Electronic Control Models
The ECO high temperature limit switch is located inside the immersion
Temperature Probe (two red wires) on ELECTRONIC CONTROL
models. The ECO switch contacts will open when the water
temperature reaches approximately 202°F/94°C. When the ECO
switch contacts open (activate) the electronic control system locks
out and displays a Fault message. Voltage to the contactor coils and
heating elements is terminated to prevent further heating operation.
Should the ECO activate, the water temperature must drop below
140°F/60°C before the control system can be reset. Once the water
temperature has cooled below this point the power supply to the water
heater must be turned off and on again to reset the control system.
THERMOSTAT CONTROLS
The water heaters covered in this instruction manual are equipped with
adjustable thermostat controls to control water temperature. Hot water
temperatures required for automatic dishwasher and laundry use can
cause scald burns resulting in serious personal injury and/or death.
The temperature at which injury occurs varies with the persons age and
duration of exposure. The slower response time of children, the elderly
or disabled persons increases the hazards to them. Never allow small
children to use a hot water tap or draw their own bath water. Never
leave a child or disabled person unattended in a bathtub or shower.
The water heater should be located in an area where the general
public does not have access to set temperatures.
Setting water heater temperatures at 120°F (49°C) will reduce risk of
scalds. Some areas require settings at specic lower temperatures.
THERMOSTAT SETTINGS - SURFACE MOUNT CONTROL
Adjustment of temperature controls on surface mounted controls is
to be performed by a qualied service agent at initial start-up.
These models have multiple thermostat/ECO combination controls
one for each heating element installed. These thermostats are set
from the factory at 140°F/60°C. Set the thermostat dial at the lowest
setting which produces an acceptable hot water supply. This will
always give the most energy efcient operation.
The water heater is supplied with thermostats that may come from
different manufactures and have different temperature indications
as described below.
Thermodisc Thermostats
Thermodisc thermostats are adjustable from approximately 120°F
(49°C) (lowest setting) to 180°F (82°C) (highest setting) see gure
7A. These thermostats are set from the factory at approximately the
140°F (60°C) setting. The over temperature device (ECO high limit)
attached to each thermostat has a manual reset.
APCOM Thermostats
Apcom thermostats have three designated set points; LO, MED and
HI. See gure 7B. The approximate equivalent temperatures for these
three settings are: LO = 140°F (60°C), MED = 160°F (71°C) and HI
= 180°F (82°C). These thermostats are set from the factory at the
MED 140°F (60°C) setting. The over temperature device (ECO high
limit) attached to each thermostat has a manual reset.
APCOM
INC
40A 120-277 VAC
25A.480 VAC
125VA.PT.DTY.
120-480 VAC
MED
LO
HI
MODEL WH19HC
30A 120-250 VAC
22A 277 VAC
12.5A 480VAC
125 VA.PT.DTY. 120-480 VAC
Figure 7A Figure 7B
Table 6 shows the approximate time-to-burn relationship for normal
adult skin.
Water
Temperature °F
Time for 1st Degree
Burn
(Less Severe Burns)
Time for Permanent
Burns 2nd & 3rd
Degree
(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. Arm-
strong, Sept. 15,1978)
Table 6.
TEMPERATURE REGULATION