COMMERCIAL ELECTRIC ENERGY SAVER
WATER HEATER
MII SERIES
IMMERSION AND SURFACE MOUNTED
THERMOSTAT MODELS
SERVICE
MANUAL
Troubleshooting Guide
and Instructions for Service
(To be performed ONLY by
qualified service providers)
Models Covered
by This Manual:
MII50(A)-*-**-(SF,CF,SCF)-***
MII80(A)-*-**-(SF,CF,SCF)-***
MII120(A)-*-**-(SF,CF,SCF)-***
*Denotes kW Rating
**Denotes Warranty Years
***Denotes Wiring Code
Manual 238-47174-00B
Save this manual for future reference
Table of Contents
Page Service Procedure
I
ntroduction ………………………………………………………………………. 2 - - -
Tools……………………………………………………………………………… 2 - - -
G
eneral Information ……………………………………………………………… 3 - - -
Sequence of Operation …………………………………………………………… 10 - - -
Troubleshooting …………………………………………………………………. 13 - - -
Heating Element Testing …………….................................................................... 15 MCE-I
Line Voltage Testing………………...…………………………………………… 16 MCE-II
Fuse Testing…........................................................................................................ 17 MCE-III
High Limit (ECO) Testing (Surface Mounted Thermostats)……………………. 18 MCE-IV
High Limit (ECO) Testing (Surface Mounted Thermostats at 600V)……………. 19 MCE-V
High Limit (ECO) Testing (Contactor Models)…………………………………. 20 MCE-VI
Thermostat Operation Testing (Surface Mounted Thermostats).............................. 21 MCE-VII
Thermostat Operation Testing (Surface Mounted Thermostats at 600V)………… 22 MCE-VIII
Thermostat Operation Testing (Contactor Models)..................................................23 MCE-IX
Contactor Operation Testing……………………………………………………… 24 MCE-X
Thermostat Removal and Replacement (Surface Mounted Thermostats)…………26 MCE-XI
Thermostat Removal and Replacement (Contactor Models)………………………27 MCE-XII
ECO Removal and Replacement (Contactor Models)……………………………..28 MCE-XIII
ECO Removal and Replacement (Surface Mounted Thermostats at 600V)……….29 MCE-XIV
Heating Element Removal and Replacement …………………………………….. 30 MCE-XV
Anode Inspection and Replacement ……………………………………………… 31 MCE-XVI
Generic Parts List ………………………………………………………………… 32 - - -
Glossary of Terms……………………………………………………………….... 33 - - -
Page 2
This service manual is designed to aid service and maintenance professionals on the function, proper diagnosis and repair of
Bradford White Commercial Electric Water Heaters.
The text and illustrations in this manual provide step by step instructions to facilitate proper operation and troubleshooting
procedures. Contact the Bradford White Technical Support Group immediately if diagnosis can not be made using the
methods described in this service manual.
Introduction
MII Series Commercial Electric
Water Heaters
Tools
- Multi Meter. - Phillips Head Screw Driver.
- 1-½” Deep Well Socket. - Common Screw driver.
- 1-1/16" Deep Well Socket. - Thermometer.
- ¼" Nut Driver. - Drain Hose.
- Other Hand Tools: Pipe Wrench, Channel Locks, Pliers (common & needle nose), Wire cutters, Wire Strippers,
Allen Wrench Set, Flash Light.
2
G
ENERAL INFORMATION
Bradford White MII Series Commercial Electric water heaters can be manufactured with a choice between two
different types of thermostat control options as follows:
Surface Mounted Thermostats.
I
mmersion Thermostat (contactor models).
The model number is coded to identify the specific thermostat control system used for a particular unit. Below is
typical model number and coded definitions:
MII50 12 3 SF 018
Wiring Code
C-Contactor (Immersion Thermostat)
CF-Contactor w/Fuse (Immersion Thermostat)
S-Surface Thermostat
SF-Surface Thermostat w/Fuse
SC-Surface Thermostat (w/Contactors)
SCF-Surface Thermostat w/Fuse (w/Contactors)
Warranty
kW Rating
Tank
The wiring code at the end of the model number is used at the factory to facilitate proper construction based on the
electrical characteristics such as voltage, phase, kW rating and amp draw. In the field this information is determined
from the heaters rating plate located on the front of the water heater.
BRADFORD WHITE CORPORATION
200 LAFAYETTE ST. MIDDLE VILLE MI 49333
Model No: MII50123SF018
Serial No: ZB2564812
Cap. 50(gal.)/189.3(liters)
Press: Test 300(psi), Working 150(psi)
Volts 240 Max Temp 180°
Phase Three Amps 29
kW Each 4 Total kW 12 3 Elements
Wattage Rating Based Upon 60 Hz
Page 3
Typical Rating Plate
Located On Front Of Water Heater
Model Number
Electrical Characteristics
3
Page 4
G
ENERAL INFORMATION
Upper
Control Box
L
ower
Control Box
Ground Lug
Terminal Block
F
use Block(s)
C
ontactor(s)
High Limit (ECO) Control
Immersion Thermos tat
Control
High Limit (ECO)
Direct Immersion Bulb
Thermostat
Direct Immersion Bulb
Heating Elements
C
ontactor Models
General Controls Layout
Surface Mounted Thermostat Models
General Controls Layout
Upper
Control Box
Lower
Control Box
Ground Lug
Terminal Block
Fuse Block(s)
Heating Elements
Surface Mounted Thermostats
With ECO
4
Page 5
GENERAL INFORMATION
Upper
Control Box
Lower
Control Box
G
round Lug
Terminal Block
C
ontactor(s)
S
urface Thermostats
Heating Elements
H
igh Limit (ECO) Control
600V Surface Thermostat (w/Contactors) Models
General Controls Layout
5
G
ENERAL INFORMATION
Page 6
Surface Mounted Thermostats
M
anual
ECO (high limit)
Reset button
Temperature
c
ontrol Dial
S
urface Mount
C
ombinat ion Thermostat/
ECO (high limit)
89T Seri es
Surface mounted thermostats are mounted into a bracket above each heating element. The bracket holds the
thermostat against the side of the tank responding to tank surface temperatures to sense a call for heat, set point
temperature and high limit (ECO) activation. As each element has a dedicated thermostat (for all models excluding
600V), it is possible to sequence the elements by varying the settings on the thermostats.
The thermostat will complete control circuit
voltage upon a call for heat. Likewise, the control
will interrupt control circuit voltage when the water
temperature is sufficient to satisfy the adjustable
temperature limit of control.
Immersion Style Thermostat Control for
Contactor Models
Direct
Immersion
bulb
The high limit (ECO) control will interrupt control circuit voltage
causing the heater to shut down when the high temperature limit of
the control is reached (196°F±4°F). Once the cause for over
heated water has been determined, The control must be manually
reset to restore normal operation.
Immersion Style High Limit (ECO) Control for
Contactor Models
Direct
Immersion
bulb
Manual Reset
Buttons
6
GENERAL INFORMATION
Page 7
Surface Mounted Thermostats (w/Contactors) for
600V Models
600V models use contactors to deliver line voltage to the heating elements. However, rather than the immersion type
high limit and thermostat devices, surface mounted thermostats are used to operate the control circuit of the water
heater.
Temperature
control Dial
Surface Mounted
Thermostat
59T Series
Manual Reset
Button
Surface Mounted
ECO (High Limit)
7
G
ENERAL INFORMATION
Contactor
1-½” Hex
Screw-in Flange
Terminal Block
Screw
Terminal Block
Zinc Plated Copper or
Incoloy Sheath
Element Rating Ink Stamped
on side of Terminal Block.
Direct Immersion “Screw-in” Type Heating Element
0642
4500W 240V
RC02404524
Page 8
Contactor
operationis ac
hievedby
energizing an operating coil in res
pons
e toa callforh
eat from the immersion
thermostat. Upon a call for
heat,o
neor
moreconta
ctorswil
l ener
giz
e
allhea
tin
g elem
entssimult
a
ne
ous
l
y.
The
operating coils ar
e volt
age specific, Whencontactorreplacement is requiredbe sure to or
der the properoperatin
g coil
bas
e
on t
he v
o
lt
age rating found on t
h
e r
ati
n
g plat
e loc
a
t
ed on thefr
o
nt
ofth
e
wat
erheater
.
T
e
rminalconnections to
th
e
fus
e
bl
o
c
k an
d
/
or
t
erminal
bl
ock
Terminal connections to the
h
eating elements
T
erminal connections of
contactor operating coil.
8
G
ENERAL INFORMATION
Watts
V
olts x 1.732
W
atts = Amps x Volts
Volts
Watts
2
Commonly Used Formulas
240V 1Ph
Ungrounded
Ungrounded
Grounding
BLACK
RED
GREEN
240
120
Common Service Wire
Configurations
Page 9
120
(
balanced 3 phase)
A
mps =
Watts
Volts
(Single phase)
Amps =
O
hms =
120
ABCNeutral
RED BLACK RED
120
120
208
208 208
208 3Ph
120
ABCNeutral
RED BLACK RED
120
120
240
240 240
240 3Ph
277
ABCNeutral
RED BLACK RED
277
277
480
480 480
480 3Ph/277 1Ph
Full Load Current Amps
208 Volt
1 Ph 3 Ph
6
kW
9
12
13.5
15
18
24
27
30
36
45
54
28.8 16.6
43.2 25.0
57.6 33.3
64.9 37.5
72.1 41.6
86.5 50.0
115.4 66.7
129.8 75.0
144.2 83.3
173.0 100.0
216.3 125.0
259.6 150.0
240 Volt 277 Volt 380 Volt 415 Volt 480 Volt 600 Volt
25.0 14.4
37.2 21.6
50.0 28.9
56.2 32.5
62.5 36.1
75.0 43.4
100.0 57.8
112.5 65.0
125.0 72.2
150.0 86.7
187.5 108.3
225.0 130.0
12.5 7.2
18.7 10.8
25.0 14.4
28.1 16.2
31.2 18.0
37.5 21.6
50.0 28.9
56.2 32.5
62.5 36.1
75.0 43.3
93.7 54.1
112.5 65.0
1 Ph
21.6
32.4
43.3
48.7
54.1
64.0
86.6
97.4
108.3
129.9
162.4
194.9
3 Ph
8.3
12.5
16.7
18.8
20.9
25.0
33.4
37.5
41.7
50.1
62.6
75.1
3 Ph
9.1
13.6
18.2
20.5
22.7
27.3
36.4
41.0
45.6
54.7
68.4
82.0
3 Ph
5.8
8.7
11.5
13.0
14.4
17.3
23.1
26.0
28.9
34.6
43.3
52.0
1 Ph 3 Ph 1 Ph 3 Ph
9
S
EQUENCE OF OPERATION
MII Series Commercial Electric Water Heaters can use either immersion thermostat (contactor models) or
surface mounted thermostats. Sequence of operation for each configuration is explained below. It would be impractical
to show all wire diagrams applicable to both configurations. A “typical wiring diagram” is illustrated to aid in
understanding the principles of the operating sequence.
Immersion Thermostat (Contactor Models): Configured to use a single immersion thermostat to control one or more
contactors to energize or de-energize all elements simultaneously. In addition, a separate high limit (ECO) control with
manual reset is wired in series with the thermostat. Both controls use a direct immersion bulb inserted into the tank to
sense water temperature. Immersion thermostat and high limit control are mounted to provide temperature adjustment
and manual reset access from the exterior of the unit.
Surface Mounted Thermostats: Surface mounted thermostats are mounted inside the lower control box, in a bracket
above each heating element. The bracket holds the thermostat against the side of the tank responding to tank surface
temperatures to sense a call for heat, set point temperature and high limit (ECO) activation. As each element is controlled
by a dedicated thermostat, it is possible to sequence the elements by varying the settings on the thermostat. However,
600V models w/ surface mounted thermostats operate contactors in the same manner as an immersion thermostat
model, only using surface thermostats to sense the call for heat.
Sequence of operation for each system is explained below.
Sequence of Operation:
Immersion Thermostat (Contactor Models).
Line voltage is applied across terminals of fuse block
or a terminal block. Line voltage continues down and
connects to terminals L1, L2 & L3 of one or more
contactors.
A) Contactor is open (no call for heat), so there is no
voltage across terminal T1, T2 & T3
of contactor.
B) The contactor is controlled by the control circuit
consisting of the immersion thermostat,
ECO (hi limit) and contactor coil.
Page 10
1
2
OR
Terminal Block
F
use Block
L
ine Voltage
Contactor
Contactor
Coil
ECO
(High Limit)
T’stat
When the thermostat calls for heat, contacts close
inside the thermostat completing the circuit through
the ECO and energizing the contactor coil.
The system has two distinct circuits.
1. Power circuit (shown solid line).
2. Control Circuit (shown dotted line).
The energized contactor coil causes the contactor to
close energizing the elements from terminals T1, T2
& T3 of the contactor.
3
When the temperature setting of the thermostat is
reached, the contacts in the thermostat open. This
interrupts current flow through the control circuit deenergizing the contactor coil.
4
The de-energized contactor coil causes the contactor
to open, interrupting current flow through the
elements. The heater is now in stand-by waiting for
the next call for heat.
5
Heating Elements
10
S
EQUENCE OF OPERATION
Sequence of Operation:
Surface Mounted Thermostats.
OR
Terminal Block
F
use Block
L
ine Voltage
Heating Element
Surface Mounted
Thermostat
Line voltage is applied across terminals of fuse block or a
terminal block. Line voltage continues down and connects
to surface mounted thermostats at terminals L1 & L3.
1
1
ECO (high limit) in
thermostat is closed, so
there is line voltage present
at terminal L4 of thermostats
and to one side of each
element.
2
E
CO Closed
P
ower to one
side of element
2
3
Water in tank is cold, so
all thermostats are
closed at terminal T2
(calling For heat). This
completes the circuit and
allows current to flow
through heating elements.
3
Thermostat closed
at terminal T2
4
As each thermostat is
satisfied, it opens at
terminal T2 interrupting
current flow through the
respective element. The
system is now in stand-by
mode, waiting for the next
call for heat.
4
Thermostat open
at terminal T2
Page 11
11
SEQUENCE OF OPERATION
Sequence of Operation:
600V Surface Mounted Thermostats (w/Contactors).
Line voltage is applied across terminals of fuse block
or a terminal block. Line voltage continues down and
connects to terminals L1, L2 & L3 of one or more
contactors.
A) Contactor is open (no call for heat), so there is no
voltage across terminal T1, T2 & T3
of contactor.
B) The contactor is controlled by the control circuit
consisting of the surface mounted thermostat,
ECO (hi limit) and contactor coil.
Page 12
1
2
Contactor
Fuse Block
Line Voltage
When the thermostat calls for heat, contacts close
inside the thermostat completing the circuit through
the ECO and energizing the contactor coil.
T
he system has two distinct circuits.
1. Power circuit - Line Voltage (600V)
2. Control Circuit - 120V
The energized contactor coil causes the contactor to
close, energizing the elements from terminals T1, T2
& T3 of the contactor.
3
When the temperature setting of the thermostat is
reached, the contacts in the thermostat open. This
interrupts current flow through the control circuit deenergizing the contactor coil.
4
The de-energized contactor coil causes the contactor
to open, interrupting current flow through the
elements. The heater is now in stand-by waiting for
the next call for heat.
5
Heating Elements
High Limit
59T
Transf ormer
60VA
59T
Notice in the wiring diagram at right that each row of
elements is equipped with a surface mounted
thermostat on the highest element in the row. These
thermostats are individually wired in series to the
contactor whose line voltage corresponds to the same
row of elements. Each thermostat and contactor
combination are wired to the high limit (ECO) device
in parallel. This allows for each row of elements to be
powered “ON” independent of the other element rows.
However, the high limit (ECO) is wired in series so
that voltage can be interrupted to the entire control
circuit if the ECO senses that the tank water has
become overheated.
6
6 Element Configuration Shown
(9 Elements Possible)
12
T
ROUBLESHOOTING
Most common cause for improper electric water heater operation can be linked to heating element
failure.
When troubleshooting an electric water heater with the incidence of “No Hot Water” or “Insufficient Amount of Hot
Water” It is always a good idea to check the heating elements first following the procedure on page 15.
Common Heating Element Failures Are:
1. Dry Firing. Elements may be partially submerged in water or most likely, completely exposed with no water
in the tank at all. In open air, an energized element (Dry Fired) will become completely inoperable within
seconds. In some cases sediment or lime build up around an element can eventually cause an air pocket,
resulting in a dry fired element. When element replacement is required, be sure tank is full of water prior to
energizing the water heater.
2. Grounded Element. In most cases, an element with a short circuit to ground will cause the circuit breaker in
the service panel to open or shut off. In some cases there may not be enough current draw for the circuit
breaker to open. This will allow the heating element to be in continuous operation resulting in over heated
water, limited only by the ECO or Energy Cut Off located in the thermostat circuit. Repeated actuation of the
ECO usually is the result of a grounded heating element.
3. Sediment build up. Slow hot water recovery can usually be traced back to sediment or lime build up around
heating element. Sediment build up can also over time cause a dry fired element.
If a heating element is found to be inoperative, it must be replaced. Follow service procedure MCE-XV on page 30.
The illustration below shows a common “Screw-In” type heating element identifying certain features commonly referred
to throughout this manual.
1-½ Hex
Screw-in Flange
Terminal Block
Screw
Terminal Block
Zinc Plated Copper or
Incoloy Sheath
Element Rating Ink Stamped
on side of Terminal Block.
Typical Direct Immersion “Screw-In”
Type Heating Element
Page 13
0642
4500W 240V
RC02404524
13
SYMPTOM PROBABLE CAUSE CORRECTIVE ACTION
No Hot Water
1. No power to heater.
2. Blown water heater fuses.
3. Loose wire connections.
4. Inoperative heating elements.
5. Inoperative thermostat(s).
6. Open ECO.
7. Inoperative contactor(s).
1. Inoperative heating element.
2. Sediment or lime build up on element(s).
3. Thermostat(s) set to low.
4. Inoperative thermostat(s).
5. Inoperative contactor(s).
6. Loose wire connection.
7. High demand period.
8. Undersized heater.
9. Very cold inlet water to heater.
10. Plumbing connections reversed.
Not Enough Hot
Water or
Continues
Operation
Slow Hot Water
Recovery
1. Sediment or lime build up on element(s).
2. Loose wire connections.
3. Inoperative thermostat(s).
4. Inoperative contactor(s).
5. Derated heating element installed.
Over Heated
Water
1. Surface thermostat(s) not flush with tank.
2. Grounded heating element(s ).
3. Thermostat set to high.
4. Inoperative thermostat(s).
5. Inoperative ECO.
1. Check circuit breakers at service panel.
2. Check water h eater f uses.
3. Check all wire connections.
4. Check heating element(s).
5. Check thermostat(s) operation.
6. Rese t (check) ECO.
7. Check contactor operation.
1. Check heating element(s).
2. Clean or repl ace heating element(s)
3. Incr ease thermost at sett ing.
4. Check thermostat(s).
5. Check contactor operation.
6. Check all wire connection.
7. Redu ce demand.
8. Replace with larger heater.
9. Temper water to heater.
10. Correct plumbin g connections.
1. Clean or repl ace heating elements.
2. Check all wire connections.
3. Check thermostat(s).
4. Check contactor operation.
5. Verify element voltage and wattage rating.
1. Check surface thermostat(s) mounting.
2. Check heating element(s).
3. Adjust therm ostat(s) to desired setting.
4. Check thermostat(s).
5. Check ECO.
SERVICE
PROCEDURE
2. MCE-III, Page 17
4. MCE-I, Page 15.
5
. MCE-VII-IX, Page 21-23.
6. MCE-IV-VI, Page 18-20.
7. MCE-X, Page 24,25
1. MCE-I, Page 15.
2. MCE-XV, Page 30.
4. MCE-VII-IX, Page 21-23.
5. MCE-X, Page 24,25
1. MCE-XV, Page 30.
3. MCE-VII-IX, Page 21-23.
4. MCE-X, Page 24-25
5. See page 8.
1. MCE-XI, Page 26.
2. MCE-I, Page 15.
4. MCE-VII-IX, Page 21-23.
5. MCE-IV-VI, Page 18-20.
Page 14
Noisy (singing or
hissing) Elements
1. Lime formation on elements.
2. High or low line voltage.
1. Clean or repl ace heating elements.
2. Verify line voltage to heater.
1. MCE-XV, Page 30.
2. MCE-II, Page 16.
T
ROUBLESHOOTING
WARNING
High voltage exposure. Use caution when
making voltage checks to avoid hazard to
life or property.
Noisy Contactor
1. Low line voltage.
2. Debris between contactor plates.
3. Incorrect or defective operating coil.
4. Loose wire connections.
1. Verify line voltage to heater
2. Replace cont actor.
3. Replace cont actor.
4. Check wire connections.
1. MCE-II, Page 16
Quick Step Plan to Hot Water
1. STOP, DANGER! Turn power “OFF” to water heater.
2. Check all wire connections to insure they are snug
and corrosion free.
3. Reset high limit (ECO) (page 18-20).
4. Check for inoperative heating element (page 15).
5. Check line voltage (pg 16), and internal fuses (page 17).
6. Refer to table below if items 1 through 5 above do not correct problem.
14
SERVICE PROCEDURE MCE-I
Heating Element Testing
1. STOP, DANGER! Turn power “OFF” to water heater.
2
. Remove access cover from lower control box.
Remove insulation from inside of control box.
3. Disconnect wires from heating element.
4. Set multi-meter to “ohms” setting.
5. Touch probes of multi-meter to screw
terminals of heating element
(see illustration 1).
6. Reading should be 12.8 ohms (±6%) for a 240
volt, 4500 watt element, see table below for other elements.
A reading outside the range using the formula
above (±6%), indicates a bad element and the
element must be replaced.
Test for Open or Burned Out Element.
DANGER
High voltage exposure. To avoid hazard to
Life or property, be sure power is turned OFF
to water heater while performing this
procedure.
Test For Grounded Heating Element
(damaged heating element with short circuit to ground).
1. STOP, DANGER! Turn power “OFF” to water heater.
2. Remove access cover from lower control box.
Remove insulation from inside of control box.
3. Disconnect wires from heating element.
4. Set multi-meter to “ohms” setting.
5. Touch one probe of multi-meter to either screw
terminal of heating element and the other on
the element flange (see illustration 2). There
should be no reading on the ohm meter. Any
reading indicates a grounded element and the
element must be replaced. Repeat this step for
the other screw terminal.
Ohms = Volts
2
Watts
Element Screw Terminals
Element
Screw Terminal
Element Flange
Illustration 1
Illustration 2
Page 15
NOTE
Disconnect
element
Wires
NOTE
Disconnect
element
Wires
Ohms of electrical Resistance
For commonly Used Elements
Voltage Rating of Element
Element
Wattage 208 240 480
2000 21.6 28.8 115.2
3000 14.4 19.2 76.8
4000 10.8 14.4 57.6
4500 9.6 12.8 51.2
5000 8.7 11.5 46.1
6000 7.2 9.6 38.4
15
SERVICE PROCEDURE MCE-II
Line Voltage Testing
Page 16
Line Voltage Testing
Illustr ation 3
1. STOP, DANGER! Turn power “OFF” to water heater.
2. Open upper control panel door.
3. Determine connection point for line voltage
from service panel, terminal block or
fuse block
4. Set multi-meter to volts AC. Be sure to scale
meter for appropriate voltage.
5. Use caution and turn power “ON” to water heater.
6. Use caution and check voltage across top terminals
where service voltage connects to water heater.
(see illustration 3).
A) Rated voltage IS present, power to
the water heater is okay.
B) Rated voltage NOT present, Check
service panel.
Line voltage (single phase or three phase) will
connect to a terminal block or directly to a fuse block
located inside control panel.
Determine heaters voltage and phase by referring to the rating plate located on the front of the heater. Apply the
appropriate phase procedure below to determine if proper line voltage is present.
Single Phase Line Voltage Testing
Line voltage from
service panel
c
onnected to Terminal bloc k
o
f heater
L
ine voltage from
service panel
connected to Fuse blo ck
of heater
OR
Check voltage across
top terminals.
1. STOP, DANGER! Turn power “OFF” to water heater.
2. Open upper control panel door.
3. Determine connection point for line voltage
from service panel, terminal block or
fuse block
4. Set multi-meter to volts AC. Be sure to scale
meter for appropriate voltage.
5. Use caution and turn power “ON” to water heater.
6. Use caution and check voltage across top terminals
where service voltage connects to water heater.
(see illustration 4).
A) Rated voltage IS present, power to
the water heater is okay.
B) Rated voltage NOT present, Check
service panel.
Three Phase Line Voltage Testing
Line voltage from
service panel
connected to T erminal block
of heater
Line voltage from
service panel
connected to Fuse block
of heater
OR
Check voltage across
top terminals.
Illustration 4
DANGER
High voltage exposure. To avoid hazard to
life or property use extreme caution when
making voltage checks .
16
SERVICE PROCEDURE MCE-III
Fuse Testing
Fuse Testing
1. Turn “OFF” power to water heater.
2. Open upper control box to allow access
to fuse block.
3. Locate fuse block and remove fuses.
4. Set multi-meter to the “Ohms” setting.
5. Check continuity across fuse
(see illustration 5).
A) Continuity IS present, fuse is okay.
B) Continuity NOT present, Replace with new fuse
Illustration 5
Page 17
DANGER
High voltage exposure. To avoid hazard to Life
or property, be sure power is turned OFF to
water heater while performing this procedure.
17
SERVICE PROCEDURE MCE-IV
High Limit (ECO) Testing
Page 18
1. This procedure assumes line voltage and
fuses are in working order.
2. This procedure illustrates testing of just one
surface thermostat. Repeat this procedure for all
surface thermostats on the unit.
3. Turn power “OFF” to water heater.
4. Remove lower control box cover and remove insulation
from inside of control box.
5. Remove plastic cover from thermostat(s).
6. Turn power “ON” to water heater.
7. Check voltage across terminals L1 & L4 for all thermostats
(see illustration 6).
A) Rated Voltage IS present, ECO is okay.
B) Rated voltage NOT present, proceed to step 8.
8. Turn power “OFF” to water heater and firmly press ECO reset button on thermostat(s).
Turn power “ON” to water heater and recheck voltage across terminals L1 & L4 of thermostat(s).
A) Rated voltage IS present, the ECO has previously opened indicating the water in the tank, at
some point did overheat, Check the following:
1. Thermostat must be in full contact with tank.
2. Be sure heating element(s) is not shorted to ground (see page 15).
3. Proper thermostat operation (see page 21).
B) Rated voltage NOT present, water in tank may be over heated.
1. If water is overheated, turn “OFF” power to water heater and flow water through tank to cool below
set point of upper thermostat. Reset ECO and recheck voltage.
2. If water is cool, Replace thermostat(s).
High Limit Control (ECO) Testing for
Surface Thermostat models (not including 600V)
ECO reset
button
Illustration 6
D
ANGER
High voltage exposure. To avoid hazard to
life or property use extreme caution when
making voltage checks .
18
SERVICE PROCEDURE MCE-V
High Limit (ECO) Testing
Page 19
1. This procedure assumes line voltage, transformer,
fuses, and thermostat are in working order.
2. Turn power “OFF” to water heater.
3. Remove lower control box cover and remove insulation
from inside of control box.
4. Check for continuity across terminals 1 & 2.
(see illustration 7)
A) Continuity IS present, ECO is okay.
B) Continuity NOT present, proceed to step 5.
5. Verify power to the water heater is “OFF”, firmly press the ECO
reset button. Recheck continuity across terminals 1 & 2
(see illustration 7).
A) Continuity IS present, the ECO has previously opened indicating the water in the tank, at
some point did overheat, Check the following:
1. Thermostat must be in full contact with tank.
2. Be sure heating element(s) is not shorted to ground (see page 15).
3. Proper thermostat operation (see page 22).
B) Continuity NOT present, water in tank may be over heated.
1. If water is overheated, verify that power to water heater is “OFF”. Flow water through the tank to cool
below set point of upper thermostat. Reset ECO and recheck continuity.
2. If water is cool, Replace ECO (High Limit).
High Limit Control (ECO) Testing for
600V Surface Thermostat Models
ECO reset
b
utton
Illustration 7
D
ANGER
High voltage exposure. To avoid hazard to
life or property use extreme caution when
making voltage checks .
19
SERVICE PROCEDURE MCE-VI
High Limit (ECO) Testing
Page 20
High Limit Control (ECO) Testing for
Contactor Models
1. Determine if Hi-Limit has actuated. This can be done by simply
depressing the reset buttons. If you hear and/or feel
a small click, the switch has actuated.
2. Use caution and turn power on to water heater and observe
heating cycle following the Hi-Limit Heating Cycle flow chart.
Switch Contacts:
Normally closed.
O
pen on rise @ 196°F ±4°F
Manual Reset.
DANGER
High voltage exposure. To avoid
hazard to Life or property, be sure
power is turned OFF to water heater
while performing this procedure.
N Is water temp
over 196°F
N
Observe heating cycle.
Does switch open?
Switch OK
Is water temp
over 196°F
Replace switch
N
Y
Y
1. STOP, DANGER! Turn power “OFF” to water heater.
2. Water temperature must be below 196°F ±4°F
3. Remove Hi-Limit switch from control panel. It is not necessary
to remove immersion bulb from tank at this time. See
general controls layout on page 4 for location.
4. Disconnect wire leads to Hi-Limit Control during this test.
5. Depress reset buttons to insure switch contacts are closed.
6. Set multi-meter to Ohms setting, Check continuity Thru circuit A & B as shown in the illustrations below.
- Continuity IS present, Switch is okay.
- Continuity NOT present, Replace switch.
High Limit Control Continuity Testing for
Contactor Models
High Limit Heating Cycle Flow Chart
NOTE
Disconnect
Wire Leads to Control
Circuit “A” Continuity Testing Circuit “B” Continuity Testing
Y
20
SERVICE PROCEDURE MCE-VII
Thermostat Testing
Illustr ation 8
Water In Tank Is Cold With Power ON.
1. This procedure assumes line voltage, ECO and
elements are in working order.
2
. TURN OFF POWER TO WATER HEATER.
3. Remove access cover from lower control box.
Remove insulation from inside of control box.
Remove plastic cover from thermostat.
4. Turn power “ON” to water heater.
5. Set multi-meter to “Volts AC”.
6. Check across terminals L1 & L3 of thermostat
(see illustration 8)
A) Rated voltage NOT present,
Check fuses and or line voltage.
B) Rated voltage IS present,
proceed to next step.
7. Check across terminals L4 and T2 of thermostat (see illustration 9).
A) Rated voltage NOT present, Recheck ECO. If ECO is okay, replace thermostat.
B) Rated voltage IS present, okay, thermostat is calling for heat, go to next step.
8. Check across element terminals (see illustration 10).
A) Rated voltage NOT present, check wire connections from thermostat to element.
B) Rated voltage IS present, Repeat element testing, see page 15.
Illustration 10
Water Temperature In Tank Is Above Thermostat Setting.
1. This procedure assumes line voltage, ECO and
elements are in working order.
2. Turn power “ON” to water heater.
3. Set multi-meter to “Volts AC”.
4. See illustration 9 above, check across terminals L4 and T2 of thermostat.
A) Rated voltage IS present, replace thermostat.
B) Rated voltage NOT present, thermostat is okay.
C) Lower than rated voltage IS present, recheck for grounded element
(see page 15).
Page 21
Surface Mounted Thermostat.
Operation Testing (not including 600V models)
Illustration 9
DANGER
High voltage exposure. To avoid hazard to
life or property, use extreme caution when
making voltage checks .
21
SERVICE PROCEDURE MCE-VIII
Thermostat Testing
Water In Tank Is Cold With Power ON.
1. This procedure assumes line voltage, ECO, transformer
thermostat, and elements are in working order.
2. TURN OFF POWER TO WATER HEATER.
3. Remove access cover from lower control box.
Remove insulation from inside of control box.
4. Using a phillips head screw driver, disconnect the wire lead at
terminal 2 of the thermostat. Only check one thermostat at a time
to insure wires are correctly reinstalled upon completion.
Mark wires if necessary for reinstallation.
5. Set multi-meter to check continuity.
6. Check continuity across terminals 1 & 2 of thermostat
(see illustration 11).
A) Continuity NOT present, replace thermostat.
B) Continuity IS present, thermostat is okay.
Water Temperature In Tank Is Above Thermostat Setting.
1. This procedure assumes line voltage, ECO, thermostat, transformer, and
elements are in working order.
2. TURN OFF POWER TO WATER HEATER.
3. Remove access cover from lower control box.
Remove insulation from inside of control box.
4. Using a phillips head screw driver, disconnect the wire lead at
terminal 2 of the thermostat. Only check one thermostat at a time
to insure wires are correctly reinstalled upon completion.
Mark wires if necessary for reinstallation.
5. Set multi-meter to check continuity.
6. See illustration 11 above, check across terminals 1 & 2 of thermostat.
A) Continuity IS present, replace thermostat.
B) Continuity NOT present, thermostat is okay.
Page 22
600V Surface Mounted Thermostat Models.
Operation Testing
DANGER
High voltage exposure. To avoid hazard to
life or property, use extreme caution when
making voltage checks .
Illustration 11
22
SERVICE PROCEDURE MCE-IX
Thermostat Testing
Immersion Thermostat Operation Testing
Thermostat Control Continuity Testing.
1. This procedure assumes line voltage, ECO and contactor(s) are in working order.
2. STOP, DANGER! Turn power “OFF” to water heater.
3. Remove lower control box cover and insulation.
4. Locate thermostat control (see general controls layout on page 4) and remove wire leads to control screw terminals.
5. Water temperature in tank must be within operating range of thermostat for this test. If above or below, it will be
necessary to drain tank and remove thermostat immersion bulb from tank to warm or cool the bulb to be
within operating range of thermostat.
6. Set multi-meter to the “Ohms” setting.
7. Rotate thermostat dial to highest setting.
8. Check across screw terminals of control
(see illustration 13).
A) Continuity IS present, okay,
Go to step 9.
B) Continuity NOT present,
replace thermostat.
9. Rotate thermostat dial to lowest setting.
10. Check across screw terminals of control
(see illustration 13).
A) Continuity NOT present, thermostat is okay,
B) Continuity IS present, replace thermostat.
Providing the water temperature in tank is within the operating range of the
thermostat, checking thermostat operation can be as simple as rotating the
thermostat dial and listening to the contactor(s) to see if they respond to a call
for heat.
Use caution and turn Power “ON” and rotate the thermostat dial to call for heat.
With water temperature below the thermostat setting, the contactor(s) close.
With the contacts closed, use caution and check for rated voltage across lower
terminals of contactor(s) (see illustration 12), If rated voltage is present, the
thermostat is calling for heat.
Rotate thermostat dial to the minimum setting. With water temperature above
the thermostat setting the contactor(s) will open. With the contacts open,
voltage should not be present at lower terminals of contactor(s).
Follow the procedure below If preliminary testing above does not verify
thermostat operation.
Thermostat Specification:
Calibration: 184°F/176°F
Max Differential: 6°F
Operating Range 80 to 180°F
Page 23
DANGER
High voltage exposure. To avoid hazard to
life or property use extreme caution when
making voltage checks .
T1T2T3
L1 L2 L3
Check voltage across
l
ower terminals of contactor(s)
NOTE: Disconnect
Wire Leads to Control
Screw Terminals
Thermostat
Dial
Thermostat Immersion Bulb
Illustration 12
Illustration 13
23
SERVICE PROCEDURE MCE-X
Contactor Testing
Contactor Operation Testing
Noisy or chattering contactor operation in most cases is due to voltage variations being supplied to the water heater.
E
xtended periods of voltage variations will cause damage to the operating coil of the contactor causing noisy operation.
Determine that service voltage to the unit meets the electrical requirements per the rating plate located on the front of
the water heater.
In addition, debris between the contact plates will cause noisy operation.
Noisy Contactor
Contactor Operating Coils
Contactor operation is achieved by energizing an operating coil in response to a call for heat from the thermostat. There
are three different operating coils used depending on voltage rating of the water heater as follows:
Description Color Code
208/240 Volt Coil Green
277 Volt Coil Blue
480 Volt Coil Black
All the coils have a color code for visual conformation. In addition, the 277 & 480 volt coils are labeled with voltage rating
for proper identification. All contactors supplied for replacement are equipped with The 208/240 volt operating coil. By
removing the rear mounting plate of the contactor, the operating coils can be changed based on desired service voltage.
When contactor replacement is required be sure to order the proper operating coil base on the voltage rating found on
the rating plate located on the front of the water heater.
Color Code Location
Identification Label Location
Rear Mounting Plate
Operating Coil
Page 24
DANGER
High voltage exposure. To avoid hazard to
life or property, use extreme caution when
making voltage checks .
24
SERVICE PROCEDURE MCE-X
Contactor Testing
Page 25
Contactor Operation Testing (continued)
This procedure assumes control circuit is operating correctly.
Providing the water temperature in tank is within the operating
range of the thermostat, checking contactor operation can be
as simple as rotating the thermostat dial and listening to the
contactor(s) to see if they respond to a call for heat.
1. Turn Power “ON” and rotate thermostat dial to the maximum
setting, with water temperature in tank below the
thermostat setting, the contactor(s) will close. With the
contacts closed, check for line voltage across operating coil
terminals (see illustration 14).
A) Line voltage IS present, okay, go to step 2.
B) Line voltage NOT present, verify control circuit
operation.
2. Check for rated voltage across lower terminals of
contactor(s) (see illustration 15).
A) Rated voltage IS present, okay,
go to step 3.
B) Rated voltage NOT present, replace
contactor.
3. Rotate thermostat dial to the minimum setting.
With water temperature in tank above thermostat
setting, the contactor(s) will open. With the contacts
open, voltage should not be present at lower terminals
of contactor(s).
4. Check for line voltage across operating coil
terminals (see illustration 14).
A) Line voltage IS present, verify control circuit
operation.
B) Line voltage NOT present, okay go to step 5.
5. Check for rated voltage across lower terminals
of contactor(s) (see illustration 15).
A) Rated voltage IS present, replace contactor.
B) Rated voltage NOT present, contactor is okay.
DANGER
High voltage exposure. To avoid hazard to
life or property, use extreme caution when
making voltage checks .
Illustration 14
T1 T2 T3
L1 L2 L3
Check voltage across
lower terminals of contactor(s)
Illustration 15
25
SERVICE PROCEDURE MCE-XI
Thermostat Removal and Replacement
Front View
Thermostat Mounting
Surface Mounted Thermostat Removal
1. STOP, DANGER! Turn power “OFF” to water heater.
2. Remove access cover from lower control box.
Remove insulation from inside of control box.
Remove plastic cover from thermostat.
3. Disconnect wires from thermostat terminals. It may be necessary to label wires for proper re-connection to
new thermostat.
4. Note thermostat temperature setting for proper setting of new thermostat.
5. Slide thermostat upwards and out of mounting bracket.
Surface Mounted Thermostat Replacement
1. Use a stiff brush to remove any debris or loose scale from tank surface where new thermostat will be installed.
2. Slide new thermostat down into thermostat bracket until it snaps into place. IMPORTANT! Thermostat must set
completely flat or flush to tank surface. An improperly installed thermostat will cause improper water heater
operation.
3. Refer to the wire diagram located on the inside of the upper control box cover and re-connect wires to the thermostat.
Be sure wire connections are snug and corrosion free. Do not over tighten, doing so may damage thermostat.
4. Set thermostat to the original thermostat setting found on the old thermostat.
5. Restore power to water heater and verify proper
heater operation.
Thermostat
Thermostat
mounting
bracket
Side View
Proper Thermostat
Mounting
Tank Surf ace
Side View
Improper Thermostat
Mounting
Proper Thermostat mounting
flush with tank surface
Improper Thermostat mounting.
Thermostat not flush with tank surface
Page 26
DANGER
High voltage exposure. To avoid hazard to
Life or property, be sure power is turned OFF
to water heater while performing this
procedure.
26
Immersion Thermostat Removal & Replacement
1. STOP, DANGER! Turn power “OFF” to water heater.
2. Turn off cold water supply to heater. Connect hose to drain
spigot of water heater and route to an open drain. Open
a nearby hot water faucet to vent heater for draining. Open
drain spigot of water heater and allow heater to drain
to a point below the Immersion bulb location
(see illustration 16 ).
3. Close drain spigot and remove hose.
4. Remove lower control box cover and insulation.
5. Locate thermostat inside lower control box mounted to
the right side of the box, below the ECO control
(see illustration 16).
6. Follow copper capillary tube from thermostat to the
immersion bulb location and remove immersion bulb
from tank, 11/16 wrench.
7. Remove (pull) thermostat control dial from stem of
thermostat.
8. Remove the two thermostat mounting screw screws
located under thermostat dial (see illustration 16).
9. Once thermostat is removed, disconnect
wire leads to the thermostat. NOTE: It may be
necessary to identify wires for proper reconnection to
new thermostat.
10. Refer to wiring diagram located on the inside of the
upper control box cover and properly reconnect wire
leads to new thermostat and remount control inside
control box using screws from step 8.
11. Replace control dial to stem of thermostat.
12. Loosen ferrule nut of immersion bulb.
(see illustration 17)
SERVICE PROCEDURE MCE-XII
Thermostat Removal and Replacement
Immersion
bulb
Ferrule
nut
Copper
capillary
tube
Tank
nut
13. Position tank nut at end of immersion bulb as shown in illustration 17. Insert immersion bulb into tank and tighten
tank nut.
14. Gently pull copper capillary tube to insure the immersion bulb is in a horizontal position as shown in illustration 17
and tighten ferrule nut.
15. Resume water supply, fill tank and check for leaks.
16. Be sure tank is full or water and resume power supply to water heater. Verify proper thermostat operation.
Page 27
DANGER
High voltage exposure. To avoid hazard to
Life or property, be sure power is turned
OFF to water heater while performing this
procedure.
Immersion
Thermostat Bulb
L
ocation
Copper Capillary
Tube
Immersion
Thermostat
control
Thermo stat control
Mounting Screws
Located Under
Thermostat Dial
E
CO
Control
Illustration 16
Illustration 17
27
SERVICE PROCEDURE MCE-XIII
C
ontactor Model High Limit (ECO) Control
Removal and Replacement
Page 28
Contactor Model High Limit (ECO) Control
Removal and Replacement
1. STOP, DANGER! Turn power “OFF” to water heater.
2. Turn off cold water supply to heater. Connect hose to drain
spigot of water heater and route to an open drain. Open
a nearby hot water faucet to vent heater for draining. Open
drain spigot of water heater and allow heater to drain
to a point below the Immersion bulb location
(see illustration 18).
3. Close drain spigot and remove hose.
4. Remove lower control box cover and insulation.
5. Locate ECO control inside lower control box mounted to
the right side of the box, above the thermostat control
(see illustration 18).
6. Follow copper capillary tube from ECO control to the
immersion bulb location and remove immersion bulb
from tank, 11/16 wrench.
7. Remove the two ECO control mounting screws
located outside the lower control box.
8. Once ECO control is removed, disconnect
wire leads to the control. NOTE: It may be
necessary to identify wires for proper reconnection to
new control.
9. Refer to wiring diagram located on the inside of the
upper control box cover and properly reconnect wire
leads to new ECO control and remount control inside
control box using screws from step 7.
10. Loosen ferrule nut of immersion bulb.
(see illustration 19)
Immersion
bulb
Ferrule
nut
Copper
capillary
tube
Tank
nut
11. Position tank nut at end of immersion bulb as shown in illustration 19. Insert immersion bulb into tank and tighten
tank nut.
12. Gently pull copper capillary tube to insure the immersion bulb is in a horizontal position as shown in illustration 19
and tighten ferrule nut.
13. Resume water supply, fill tank and check for leaks.
14. Be sure tank is full of water and resume power supply to water heater. Verify proper ECO operation.
DANGER
High voltage exposure. To avoid hazard to
Life or property, be sure power is turned
OFF to water heater while performing this
procedure.
ECO
Immersion Bulb
L
ocation
Copper C apillary
Tube
Illustration 18
Illustration 19
Thermostat
Control
E
CO
C
ontrol
28
SERVICE PROCEDURE MCE-XIV
6
00V Model High Limit (ECO) Control
Removal and Replacement
Page 29
600V Surface Thermostat Model
High Limit (ECO) Control
Removal and Replacement
1. STOP, DANGER! Turn power “OFF” to water heater.
2. Remove lower control box cover and insulation.
3. Locate high limit switch mounted to the tank above the
element spuds (see illustration 20).
4. Disconnect wire leads to the high limit. NOTE: It may be
necessary to identify wires for proper reconnection to
new control.
5. Remove the two high limit mounting nuts holding the
sensor to the tank. Take care not to damage the
mounting studs.
6. Fasten the replacement high limit to the tank using the
nuts from step 5. Take care not to damage the mounting
studs. Refer to wiring diagram located on the inside of
the upper control box cover and properly reconnect wire
leads to new high limit.
7. Verify proper ECO operation.
DANGER
High voltage exposure. To avoid hazard to
Life or property, be sure power is turned
OFF to water heater while performing this
procedure.
Mounting Stud
High Limit Switch
Illustration 20
29
SERVICE PROCEDURE MCE-XV
H
eating Element Removal
and Replacement
Heating Element Removal
1. STOP, DANGER! Turn power “OFF” to water heater.
2. Turn off cold water supply to heater. Connect hose to drain
spigot of water heater and route to an open drain. Open
a nearby hot water faucet to vent heater for draining. Open
drain spigot of water heater and allow heater to drain
to a point below the Element(s).
3. Close drain spigot and remove hose.
4. Remove access cover from lower control box.
Remove insulation from inside of control box.
Remove plastic cover from thermostat.
5. Disconnect wires from element terminals.
6. Remove element from tank using 1-½” deep well socket or appropriate wrench. Unscrew element counter-clockwise
to remove from tank.
7. Be sure to remove old element gasket from the tank. It is not recommended to be re-used.
Heating Element Replacement
1. Check new element terminal block for proper electrical rating. NOTE: Some elements have dual ratings, be sure to
check all surfaces of the element terminal block (see illustration below).
2. Apply new element gasket to the new element. Be sure gasket is seated flat against element flange without rolls or
gaps (see illustration below).
3. Clean any debris from element fitting on tank.
4. Thread new element clockwise into tank. Tighten element using 1-½” deep well socket or appropriate wrench. Do not
over tighten, over tightening may damage element gasket.
5. Reconnect wires to element, be sure connections are snug and corrosion free. Do not over tighten, doing so may
damage terminal block.
6. Resume water supply to heater, be sure tank is full of water and check for leaks.
7. Re-install plastic thermostat protector(s).
8. Re-install insulation and control box cover.
9. To resume operation, BE SURE TANK IS FULL OF WATER and restore power to water heater. Verify proper heater
operation.
WARNING
Heater components and stored water may be
HOT when performing the following steps in
this procedure. Take necessary precaution to
prevent personal injury.
0642
4500W 240V
RC02404524
Date Code
Element Rating.
Example : (4500 Watt, 240 Volt)
Manufacturer Identification
Element Flange
Element Gasket Seated Flat Against
Element Flange Without Rolls or Gaps
Page 30
Terminal
Block
DANGER
High voltage exposure. To avoid hazard to
Life or property, be sure power is turned OFF
to water heater while performing this
procedure.
30
Page 31
WARNING
Heater components and stored water may be HOT when performing the following steps in
this procedure. Take necessary precaution to prevent personal injury.
SERVICE PROCEDURE MCE-XVI
Anode Inspection and Replacement
Anode Inspection and Replacement
1. Turn power “OFF” to water heater.
2. Turn off cold water supply to heater. Connect hose to drain spigot of water heater and route to an open drain.
Open a nearby hot water faucet to vent heater for draining. Open drain spigot of water heater and allow
heater to drain to a point below the anode locations at the top of the tank.
3. Close drain spigot and remove hose.
4. Remove the plastic anode access plugs at the anode locations.
5. Remove anode from the water heater (1-1/16" socket).
6. Visually Inspect anode. Anode should show signs of depletion, this is normal.
If depletion is ½ of the original anode diameter (original diameter approximately ¾”), replacement is
recommended. If any of the steel core of the anode is exposed, replacement is recommended.
7. Upon completion of inspection or subsequent replacement, reinstall anode into heater. resume water supply, refill
heater with water and check for leaks.
8. To resume operation, BE SURE HEATER IS FULL OF WATER and turn power “ON” to water heater.
Anode Rod Locations
D
ANGER
High voltage exposure. To avoid hazard to Life
or property, be sure power is turned OFF to
water heater while performing this procedure.
31
Page 32
G
eneric Parts List
32
G
eneric Parts List
Item Description
1 Anode.
2 Hot Water Outlet Nipple.
3 T&P Nipple.
3A T&P Coupling.
4 T&P Relief Valve.
5 High Limit Switch.
5A Surface High Limit Switch.
6 Hex Nut
7 Lock Washer
8 Screw
9 High Limit Spacer.
10 Cleanout O-Ring.
10A Cleanout Gasket (ASME).
11 Cleanout Cover.
11A Cleanout Cover (ASME).
12 Cleanout Cover Screw.
12A Cleanout Cover Screw (ASME)
13 Cleanout Access Cover.
14 Brass Drain Valve.
15 Escutcheon.
16 Drain Extender.
17 Thermostat Dial
18 Screw.
19 Immersion Thermostat.
20 Heating Element.
21 Surface thermostat Bracket.
22 Surface Thermostat.
23 Surface Thermostat Cover.
24 Lower Control Box Cover.
25 Heating Element Plug.
Item Description
2
6 Heating Element Gasket.
27 Cold Water Inlet Nipple.
28 Plastic Snap Bushing.
29 Lower Control Box.
30 Upper Control Box.
31 Terminal Block (Block A)
32 Terminal Block End (used for block A).
33 Terminal Block 2 pole.
34 Terminal Block 3 Pole.
35 Screw.
36 Fuse Block 2 Pole Class G
37 Fuse Block 3 Pole Class G
38 Fuse Block 3 Pole Class J
39 Contactor 3 Pole.
40 Contactor 4 Pole.
41 Screw.
42 Contactor Coil
43 Fuse Class G
44 Fuse Class J
45 Fuse Class J
46 Ground Lug Small.
47 Ground Lug Large.
48 Screw.
49 ¾ NPT Plug.
50 Transformer - 120V
Page 33
Glossary of Terms
Term Definition Unit of measure
Voltage - Electrical potential Volts
Current- Rate of voltage flow Amperes (amp)
Resistance- Ability of a device to dissipate Ohms
power irreversibly
Energy- Ability to do work kW/hr, Joule
Power- Energy per unit of time Watts, kW, VA
One kilowatt (1kW) = 1,000 Watts. = 3,412 BTU BTUH = British thermal units per hour
DC = Direct Current PSI = Pounds per square inch
AC = Alternating Current GPM = Gallons per minute
Hz = Hertz GPH = Gallons per hour
ECO = Energy cut off
°F = Degrees Fahrenheit NPT = National pipe thread
°C = Degree Centigrade ASME = American Society of Mechanical Engineers
33
NOTES
Page 34
34
NOTES
Page 34
35
Email
parts@bradfordwhite.com
techserv@bradfordwhite.com
www.bradfordwhite.com
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