Bradford White EF Series User manual

The Bradford White
Ultra High Efficiency Water Heaters
SERVICE
MANUAL
Troubleshooting Guide
and Instructions for Service
(To be performed ONLY by
qualified service providers)
For the Bradford White
eF Series®Ultra High
Efficiency Models:
EF60T125E*(NA,XA)(2)
EF60T150E*(NA,XA)(2)
EF60T199E*(NA,XA)(2)
EF100T150E*(NA,XA)(2)
EF100T199E*(NA,XA)(2)
EF100T250E*(NA,XA)(2)
EF100T300E*(NA,XA)(2)
(*) Denotes Warranty Years
Manual 45817A Save this manual for future reference

Page 2
Table of Contents
Page eF Service Procedure
Introduction 3 - - -
How to use this manual 4 - - -
Tool required for service 4 - - -
Specifications 5 - - -
Sequence of Operation 8 - - -
Troubleshooting 10 - - -
Thermostat Circuit, Testing & Replacement 12 I
Combustion System Testing and Replacement 18 II
Burner Tube Inspection & Replacement 22 III
Gas Valve Replacement 24 IV
Blower Testing and Replacement 25 V
Exhaust Pressure Switch Testing and Replacement 27 VI
Hot Surface Igniter Testing and Replacement 30 VII
Flame Sensor Testing and Replacement 32 VIII
Ignition Module Replacement 34 IX
Transformer Replacement 35 X
Intake Pressure Testing and Replacement 36 XI
Vent Safety Switch Testing and Replacement 38 XII
Anode & Flue Baffle Inspection and Replacement 40 XIII
Installation Check List 44 - - -
Heater Service Report 45 - - -
Parts List 46 - - -
Glossary of Terms 49 - - -
The Bradford White
Ultra High Efficiency Water Heaters
Page 2
R
The Bradford White
Ultra High Efficiency Water Heaters

Introduction
The Bradford White eF Series Ultra High Efficiency Water Heater uses a low Nox
premix power burner located at the top of the water heater to direct a turbulent
flame down into a submerged combustion chamber. This turbulence causes a
thorough mixing of gas and air for optimum combustion. The combustion gases
then travel through a three pass flue system keeping the gases moving at a high
velocity. The combination of high turbulence and velocity results in an optimum
transfer of heat from the flue gases into the water.
Burner operation is controlled using an electronic ignition module. The module
monitors the status of the electronic thermostat, vent temperature limit switch, vent
system pressure switches and a flame sensor to control output voltage to blower
motor, hot surface igniter and gas valve. The module contains programming which
determines the sequence of operation and timings for purge periods, trial for
ignition, flame sensing and lockout. The module will also provide diagnostic
information on LEDs to help in determining the cause of system lockouts.
The contents in this manual are detailed informational tools to assist in the proper
diagnosis of the eF Series Ultra High Efficiency Water Heater operational faults.
Please read this service manual completely and provide as much information
regarding the eF Series Ultra High Efficiency Water Heater operation and
installation specific concerns.
The Bradford White eF Series Ultra High Efficiency Water Heater is designed to
deliver a remarkable thermal efficiency rating in a quiet running unit with venting
options that allow for installation flexibility. Several technologically advanced
design features are incorporated in the design that will require additional
knowledge on the part of the qualified service provider. The information in this
manual will instruct service and maintenance professionals on the function, proper
diagnosis and repair of The Bradford White eF Series Ultra High Efficiency Water
Heater.
Page 3
R
R
R
R
R
Page 3
®
®
®
®
®

Tools Required for Service
It is intended for this manual to be used by qualified service personal for the primary purpose of
troubleshooting analysis and repair of the Bradford White eF Series Ultra High Efficiency Water
Heater. Understanding the sequence of operation section of this manual will contribute greatly to
troubleshooting this product.
An “Installation Check List” is shown on page 44. Compare the installation against the installation
check list to confirm all requirements are met.
An “eF Service Report” is shown on page 45. Completing this form will assist in the
troubleshooting efforts. Should you need to call for technical support, Please provide the
information shown on this form to the support technician to insure accurate troubleshooting.
Troubleshooting begins with “System Observation” to determine failure mode as indicated by the
LED status of the ignition module. Troubleshooting continues with “Failure Modes and Probable
cause” listed on page 11 directing the service provider to a series of test procedures to determine
root cause of failure. Component replacement procedures directly follow the test procedures for a
given component.
In some difficult to diagnose conditions, it may be necessary to isolate the heater from the vent
system to determine root cause.
Contact Technical support immediately if diagnosis is not determined using the methods described
in this service manual.
Page 4
Manometer: Two types available, a liquid “U” tube type or a digital (magna-helic)
type. This device is used to measure gas and/or air pressures and
vacuum.
Multi-Meter: A digital type is strongly recommended. This device is used to measure
electrical values. The meter you select must have the capability to
measure volts AC, volts DC, Amps, micro-amps and ohms.
Thermometer: Used to measure water temperature. An accurate thermometer is
recommended.
Water Pressure Gage: Used to measure water supply pressure. Also used to determine tank
pressure by adapting to the drain valve of the heater.
Jumper Leads: A length or wire (12" min.) with alligator clip at both ends.
Various Hand Tools: Pipe wrench, channel locks, open end wrench set, 12" crescent wrench,
Allen wrench set, torx bit set, screw drivers (common & phillips), long
reach (12") magnetic tip phillips head screw driver #2 tip, ¼" nut driver,
pliers (common & needle nose), socket set including a 1-1/16 deep well
socket, wire cutters, wire strippers, wire crimpers, torpedo level, small
shop vac, step ladder, and flashlight.
How to Use This Manual
R
Page 4
®

Specifications
Page 5
EF60T125
EF60T150
EF60T199
EF100T150
EF100T199
EF100T250
EF100T300
125,000
150,000
199,999
150,000
199,999
250,000
300,000
187
211
265
250
309
364
405
363.6
422.7
557.6
450.5
597
734.8
836.4
145.5
169.1
223
180.2
238.8
293.9
334.5
103.9
120.8
158
129
171
210
239
60
60
60
100
100
100
100
96.0
93.0
92.0
99.1
98.5
97.0
92.0
57
57
57
77 5/8
77 5/8
77 5/8
77 5/8
28 3/8
28 3/8
28 3/8
28 3/8
28 3/8
28 3/8
28 3/8
5
5
5
5
5
5
5
13
13
13
13
13
13
13
40
40
40
60
60
60
60
42 ¼
42 ¼
42 ¼
62 ¼
62 ¼
62 ¼
62 ¼
52 ½
52 ½
52 ½
73 1/8
73 1/8
73 1/8
73 1/8
53 ½
53 ½
53 ½
74 ¾
74 ¾
74 ¾
74 ¾
1 ½
1 ½
1 ½
1 ½
1 ½
1 ½
1 ½
1
1
1
1
1
1
1
¾
¾
¾
¾
¾
¾
¾
¾
¾
¾
¾
¾
¾
¾
570
570
570
900
900
900
900
Shpg
Wt
(lbs)
T&P
Valve
Open
Gas
Conn
Dia
Space
Heating
Conn
Dia
Front
Wtr
Conn
Dia
H
Flr to
Gas
Conn
G
Flr. To
Air
Intake
F
Flr To
Outlet
Wtr
Conn
E
Flr to
T&P
Valve
Conn
D
Flr to
Inlet
Wtr
Conn
C
Flr
to
Vent
Outlet
B
Dia
A
Ht
Therm
Eff
%
Stg
Cap
U.S.
Gal
140°F100°F40°F
1
st
Hr
Del
Gal
at
100°F
Rise
Input
Rate
BTU/h
Model No
Recovery GPH
at Degree Rise
DIMENSIONS (INCHES)
Page 5
EF60T125
EF60T150
EF60T199
EF100T150
EF100T199
EF100T250
EF100T300
125,000
150,000
199,999
150,000
199,999
250,000
300,000
187
211
265
250
309
364
405
363.6
422.7
557.6
450.5
597
734.8
836.4
145.5
169.1
223
180.2
238.8
293.9
334.5
103.9
120.8
158
129
171
210
239
60
60
60
100
100
100
100
96.0
93.0
92.0
99.1
98.5
97.0
92.0
57
57
57
77 5/8
77 5/8
77 5/8
77 5/8
28 3/8
28 3/8
28 3/8
28 3/8
28 3/8
28 3/8
28 3/8
5
5
5
5
5
5
5
13
13
13
13
13
13
13
40
40
40
60
60
60
60
42
42
42
62
62
62
62
52
52
52
73 1/8
73 1/8
73 1/8
1/2
1/2
1/2
73 1/8
1/4
1/4
1/4
1/4
1/4
1/4
1/4
1/2
1/2
1/2
1/2
1/2
1/2
1/2
3/4
3/4
3/4
1/2
1/2
1/2
3/4
3/4
3/4
3/4
3/4
3/4
3/4
3/4
3/4
3/4
3/4
3/4
3/4
3/4
3/4
53
53
53
74
74
74
74
1
1
1
1
1
1
1
1
1
1
1
1
1
1
570
570
570
900
900
900
900
Shpg
Wt
(lbs)
T&P
Valve
Open
Gas
Conn
Dia
Space
Heating
Conn
Dia
Front
Wtr
Conn
Dia
H
Flr to
Gas
Conn
G
Flr. To
Air
Intake
F
Flr To
Outlet
Wtr
Conn
E
Flr to
T&P
Valve
Conn
D
Flr to
Inlet
Wtr
Conn
C
Flr
to
Vent
Outlet
B
Dia
A
Ht
Therm
Eff
%
Stg
Cap
U.S.
Gal
140°F100°F40°F
1
st
Hr
Del
Gal
at
100°F
Rise
Input
Rate
BTU/h
M od el No
Recovery GPH
at Degree Rise
DIMENSIONS (INCHES)

Thermostat Sensor 11,900 Ohms @ 70°F, ECO opens @ 201°F Max., ECO close @ 100°F Min.
Thermostat Board Max temp 180°F, Min temp 91°F, 24VAC, 60Hz max.
Hot Surface Igniter 120VAC, 30-120 ohms @ room temperature.
Flame Sensor Output Minimum 1 micro amp, Typical range 4 to 7 micro amps.
Temperature Dial Min. set point 5400-6600 ohms, Max set point 0-50 ohms.
Ignition Module See page 9.
Specifications
Gas Valve Negative regulation, 24 VAC, ½" PSI max., 4.5" W.C. Minimum running
Transformer 120VAC primary, 24VAC secondary, 40VA.
Vent Safety Switch Normally closed, opens @ 350°F, manual reset.
Intake Pressure Switch 24VAC, normally closed, opens on vacuum increase @ -1.20 W.C.
Blower 120VAC, 60Hz, .6-1 amps, 6400 RPM.
Exhaust pressure switch
24VAC, normally open, closes on Pressure increase @:
+2.58" W.C. EF(60,100)T199
+1.50" W.C. EF100T150 (see note 1)
+1.22" W.C. EF60T150, EF100T250
+2.08" W.C. EF60T125
+0.55" W.C. EF100T100 (see note 2)
Note 1: +5.6" W.C. on serials prior to AH5039107
Note 2: +0.8" W.C. on serials prior to AK5288269
Power supply Dedicated 120 VAC, 60 Hz, 15A, GFI
Approved Gas Type Natural or Propane. Unit must match gas type supplied.
Venting System Power vent, balanced direct vent or unbalanced direct vent. See vent tables on page 7
Approved Vent Materials PVC, CPVC or ABS
Gas Supply Minimum ¾" NPT (schedule 40 black iron pipe recommended)
Minimum Clearance
for Servicing 18" from top, 24" from front, 4" sides and rear.
Maximum Water Supply
Pressure 150 PSI
Gas Pressure ( Nat & L.P. ) 14.0" W.C. maximum static, 4.5" W.C. minimum running (recommend 7.0" W.C. min running)
Combustion Levels CO2: 10-10.5%, CO: less then 0.04 percent (400 PPM) air free
Page 6
Page 6

Specifications
Vent Tables
Balanced Direct Vent Systems
PVC, CPVC or ABS
Total length of intake piping and exhaust
piping added together must not exceed
“Maximum Combined Length”
Shown below
Maximum Combined Length (feet)
Model Number 3"
EF60T125, EF100T150 120'
EF60T150, EF100T199
EF60T199, EF100T250
EF100T300
Unbalanced Direct Vent Systems
Air intake CAN NOT exceed exhaust by
more than 30 feet
100'
80'
60'
4"
170'
150'
130'
110'
Power Vented Systems
PVC, CPVC or ABS
Total length of exhaust piping must not
exceed “Maximum Vent Length”
Shown below
Maximum Vent Length (feet)
Model Number 3"
EF60T125, EF100T150 120'
EF60T150, EF100T199
EF60T199, EF100T250
EF100T300
100'
80'
60'
4"
170'
150'
130'
110'
Notes:
1) Multiply the total number of 90° elbows (intake and exhaust) by 5 feet. Do not include the
termination fittings or 3" condensate elbow.
2) Multiply the total number of 45° elbows (intake and exhaust) by 2 ½ feet.
3) Add this to the total length of straight pipe - intake and exhaust.
4) The sum total of all elbows and straight pipe - intake and exhaust must not exceed maximum
lengths from tables above.
Example: EF100T199
A 3" Balanced Direct vent system has 30 feet of straight exhaust pipe and 30 feet of straight
intake pipe. It has 3- 90° elbows in the exhaust and 3- 90° elbows in the intake. It has 1- 45°
elbow in the exhaust and 1- 45° elbow in the intake.
Therefore:
6- 90° elbows x 5 feet = 30 feet.
2- 45° elbows x 2½ feet = 5 feet.
60 feet of straight pipe + 30 feet + 5 feet = 95 feet.
System is within “Maximum Combined Length” from table above.
Page 7
Page 7

1
Thermostat calls for heat.
-Prior to energizing blower, ignition module checks safety circuits for normal switch positions:
a) Vent temp switch normally closed.
b) Intake pressure switch normally closed.
c) Exhaust pressure switch normally open.
If the vent temp switch is open, the control waits indefinitely for temp switch to close.
If the exhaust pressure switch contacts are closed (not in normal position), the ignition module will wait 45
seconds for pressure switch contact to open before energizing blower. If after 45 seconds and pressure switch
contacts do not open, the ignition module locks out with the PURGE light flashing indicating pressure switch
fault.
2
Blower energizes.
3
Pressure switch proves blower/vent system operation.
If the N.O. contacts of the exhaust pressure switch do not close within 5 minutes of the blower being on,
the control locks out with the PURGE light flashing indicating pressure switch fault.
4
Blower pre-purge period (5 seconds) indicated by the PURGE LED on the module.
5
Igniter warm up (18 seconds), indicated by the IGNITER LED on the module.
6
Trial for ignition (4 seconds, three trials).
a) Flame establishing period (2.5 seconds) gas valve and igniter on, indicated by the IGNITER and
VALVE LED on the module.
b) Burner on, flame proving period (1.5 seconds, looking for minimum of 1 micro amps), indicated by the
FLAME & VALVE LED on the module.
7
Steady state operation.
Ignition module monitors:
-Thermostat circuit.
-When thermostat opens, gas valve is shut down and post purge begins.
-Safety circuit.
-if vent temp switch opens, gas valve is shut down, system will post purge and wait for
switch to close before attempting reignition.
-If either pressure switch opens, Gas valve is shut down, Blower is shut down for 30
seconds after which blower is reenergized and system attempts reignition starting
at pressure switch proving mode.
-Flame sensor circuit.
-If flame is lost, gas valve is shut down, system will post purge and system attempts
reignition starting at pressure switch proving mode.
Thermostat satisfies.
Burner off.
Blower post purge (15 seconds).
Page 8
9
8
10
Sequence of Operation
Page 8

The system will go into lock out mode for the following reasons:
-Pressure switches stuck open or closed.
a) Check for exhaust or intake obstructions.
b) Check for compliance with vent tables.
c) Check for evidence of moisture or condensate present in pressure switch tubing or pressure switch.
-No ignition after 3 attempts.
A) Check gas pressures.
b) Igniter resistance too high (lower resistance preferred <150 Ohms).
C) Check venturi screw adjustment (6 ½ turns from bottom)
d) Flame sense micro amp not present (1 to 5 micro amps required).
Lock out reset is accomplished by shutting OFF the line voltage to the system or opening the 24V thermostat
circuit for at least 2 seconds.
System will automatically reset lockout after 1 hour of continuous call for heat from the thermostat. Three ignition
trials will be attempted each hour until the thermostat is satisfied.
Page 9
Sequence of Operation
Ignition Module Specifications
- Ignition & heating functions in response to thermostat.
- Hot surface ignition using a microprocessor to control timing, flame sensing using flame rectification & ignition
retries.
- Monitoring of system pressure switches and limit switches.
- Control of gas valve, inducer motor, and hot surface igniter element based on thermostat demand and status of
safety inputs.
- Diagnostic indicators to provide information on power to control and control status.
- Non-interchangeable polarized plug-in connectors for all interconnections.
Control Functions:
- Thermostat call for heat.
- Limit Switch Circuit (normally closed)
- Pressure Switch Circuit (normally open)
- Flame sensing.
- Low voltage supply.
- Line voltage supply.
Control Inputs: Control Outputs:
Lockout Conditions
- Inducer motor
- Hot surface igniter
- Gas valve
- Status indicator LEDs
Power - Green
Purge - Red
Igniter - Red
Valve - Red
Flame - Red
WIRING DIAGRAM
IGNITION MODULE
Page 9

Refer to ignition module
illustration, is there 120VAC
between P1(1) and P1(3)?
Is front panel power
switch light on,
indicating power?
Y
NPosition front panel
power switch to
“ON” position.
Is there 120VAC
across switch?
(see photo 1)
Light burned out,
replace switch.
Y
Is there 120VAC
across terminal block?
(see photo 2)
N
Determine power
source problem and
correct.
Repair/replace wire
harness to switch.
Y
N
1
Is ignition module
power light on?
N
Y
Refer to ignition module
illustration, is there 120VAC
going to module at locations
P7(1) and P7(3)?
N
Replace ignition module.
(see pg 34)
Replace ignition module.
(see pg 34)
Replace transformer.
(see pg 35)
NN
YY
Is ignition module
power and flame light
flashing?
Reset heater by
interrupting power.
Reestablish power and
Adjust thermostat to
call for heat,
tank must be cold.
Allow heater to run
through heating cycle.
Did heater complete
heating cycle and did
blower post purge?
See page 11.
System is OK.
Supply voltage polarity
is incorrect.
Y
N
N
Y
2
Refer to ignition module
illustration, is there 24VAC
going to module at locations
P2(1) and P2(2)?
IGNITION MODULE
Page 10
Troubleshooting
System Observation
WARNING
120 volt potential exposure. Use caution
making voltage checks to avoid personal injury.
Page 10
Refer to ignition module
illustration, is there 120VAC
between P1(1) and P1(3)?
Is front panel power
switch light on,
indicating power?
Y
NPosition front panel
power switch to
“ON” position.
Is there 120VAC
across switch?
(see photo 1)
Light burned out,
replace switch.
Y
Is there 120VAC
across terminal block?
(see photo 2)
N
Determine power
source problem and
correct.
Repair/replace wire
harness to switch.
Y
N
1
Is ignition module
power light on?
N
Y
Refer to ignition module
illustration, is there 120VAC
going to module at locations
P7(1) and P7(3)?
N
Replace ignition module.
(see pg 34)
Replace ignition module.
(see pg 34)
Replace transformer.
(see pg 35)
NN
YY
Is ignition module
power and flame light
flashing?
Reset heater by
interrupting power.
Reestablish power and
Adjust thermostat to
call for heat,
tank must be cold.
Allow heater to run
through heating cycle.
Did heater complete
heating cycle and did
blower post purge?
See page 11.
System is OK.
Supply voltage polarity
is incorrect.
Y
N
N
Y
2
Refer to ignition module
illustration, is there 24VAC
going to module at locations
P2(1) and P2(2)?
IGNITION MODULE
Page 10
Troubleshooting
System Observation
WARNING
120 volt potential exposure. Use caution
making voltage checks to avoid personal injury.
Refer to ignition module
illustration, is there 120VAC
between P1(1) and P1(3)?
Is front panel power
switch light on,
indicating power?
Y
NPosition front panel
power switch to
“ON” position.
Is there 120VAC
across switch?
(see photo 1)
Light burned out,
replace switch.
Y
Is there 120VAC
across terminal block?
(see photo 2)
N
Determine power
source problem and
correct.
Repair/replace wire
harness to switch.
Y
N
1
Is ignition module
power light on?
N
Y
Refer to ignition module
illustration, is there 120VAC
going to module at locations
P7(1) and P7(3)?
N
Replace ignition module.
(see pg 34)
Replace ignition module.
(see pg 34)
Replace transformer.
(see pg 35)
NN
YY
Is ignition module
power and flame light
flashing?
Reset heater by
interrupting power.
Reestablish power and
Adjust thermostat to
call for heat,
tank must be cold.
Allow heater to run
through heating cycle.
Did heater complete
heating cycle and did
blower post purge?
See page 11.
System is OK.
Supply voltage polarity
is incorrect.
Y
N
N
Y
2
Refer to ignition module
illustration, is there 24VAC
going to module at locations
P2(1) and P2(2)?
IGNITION MODULE
Page 10
Troubleshooting
System Observation
WARNING
120 volt potential exposure. Use caution
making voltage checks to avoid personal injury.

LED STATUS
Only power light
is on and heater will
not function.
Probable Cause*
Intake pressure switch.
(see page 36)
Probable Cause
Blower.
(see page 25)
Probable Cause*
Exhaust pressure
switch.
(see page 27)
LED STATUS
Purge light flashing.
LED STATUS
Valve light flashing.
Probable Cause
Flame sensor.
(see page 32)
Probable Cause
Hot surface igniter.
(see page 30)
Probable Cause*
Combustion system.
(see page 18)
Determine failure mode by observing flashing LED status on ignition module.
LED status and probable cause shown below.
* Denotes conditions that may require the heater to be isolated from the vent system to
determine root cause.
LED STATUS
Power & flame
light flashing.
Probable Cause
Supply voltage
polarity.
Probable Cause
Thermostat circuit.
(see page 12)
Probable Cause*
Exhaust pressure
switch.
(see page 27)
Probable Cause
Vent safety switch.
(see page 38)
Page 11
Troubleshooting
LED status & probable cause
Page 11

SERVICE PROCEDURE EF-I
Thermostat Circuit Testing and Replacement
Refer to ignition module
illustration, Is there 24VAC
between P3(7) and P3(8)?
Y
OK, thermostat is
calling for heat.
Turn off power to heater.
Disconnect YELLOW and RED wires from the
thermostat board at location N.O. and COM shown in
photo 3. Use a jumper to connect these two wires
together as shown in photo 3a.
Restore power to heater.
Did heater cycle on?
N
Check thermostat sensor
for proper resistance
(OHMS) across blue wires.
(See Appendix A, page 13)
Are readings correct?
(see photo 4)
Check temperature dial for
proper resistance (OHMS)
(See Appendix B, page 13)
Are readings correct?
(see photo 5)
Y
Y
Replace
thermostat sensor.
(see pg 17)
Replace temperature dial
(potentiometer).
(see pg 16)
N
N
N
Replace thermostat
circuit board.
(see pg 15)
Y
Check sensor harness
continuity.
Is there continuity?
Check temperature dial
harness continuity.
Is there continuity?
Replace harness.
Y
N
Replace harness.
N
Y
See page 14
4
5
3a
3
IGNITION MODULE
IMPORTANT NOTE: This procedure assumes a cool tank
Rotate temperature
dial to highest setting.
Thermostat
not calling
Page 12
WARNING
120 volt potential exposure. Use
caution making voltage checks
to avoid personal injury.
Page 12
SERVICE PROCEDURE EF-I
Thermostat Circuit Testing and Replacement
Refer to ignition module
illustration, Is there 24VAC
between P3(7) and P3(8)?
Y
OK, thermostat is
calling for heat.
Turn off power to heater.
Disconnect YELLOW and RED wires from the
thermostat board at location N.O. and COM shown in
photo 3. Use a jumper to connect these two wires
together as shown in photo 3a.
Restore power to heater.
Did heater cycle on?
N
Check thermostat sensor
for proper resistance
(OHMS) across blue wires.
(See Appendix A, page 13)
Are readings correct?
(see photo 4)
Check temperature dial for
proper resistance (OHMS)
(See Appendix B, page 13)
Are readings correct?
(see photo 5)
Y
Y
Replace
thermostat sensor.
(see pg 17)
Replace temperature dial
(potentiometer).
(see pg 16)
N
N
N
Replace thermostat
circuit board.
(see pg 15)
Y
Check sensor harness
continuity.
Is there continuity?
Check temperature dial
harness continuity.
Is there continuity?
Replace harness.
Y
N
Replace harness.
N
Y
See page 14
4
5
3a
3
IGNITION MODULE
IMPORTANT NOTE: This procedure assumes a cool tank
Rotate temperature
dial to highest setting.
Thermostat
not calling
Page 12
WARNING
120 volt potential exposure. Use
caution making voltage checks
to avoid personal injury.

°F012345678 9
40 26109 25400 24712 24045 23399 22771 22163 21573 21000 20445
50 19906 19383 18876 18383 17905 17440 16990 16553 16128 15715
60 15314 14925 14548 14180 13823 13477 13140 12812 12494 12185
70 11884 11592 11308 11032 10763 10502 10248 1000 9760 9526
80 9299 9078 8862 8653 8449 8250 8057 7869 7685 7507
90 7333 7165 7000 6839 6683 6531 6383 6238 6098 5961
100 5827 5697 5570 5446 5326 5208 5094 4982 4873 4767
110 4663 4562 4464 4368 4274 4183 4094 4006 3922 3839
120 3758 3679 3602 3527 3453 3382 3312 3244 3177 3112
130 3048 2986 2925 2866 2808 2752 2697 2643 2590 2538
140 2488 2439 2391 2344 2298 2253 2209 2166 2124 2083
150 2043 2004 1966 1928 1891 1856 1820 1786 1753 1720
160 1688 1656 1625 1595 1566 1537 1509 1481 1454 1427
170 1402 1376 1351 1327 1303 1280 1257 1235 1213 1191
180 1170 1150 1129 1110 1090 1071 1953 1035 1017 999
190 982 965 949 933 917 901 886 871 857 842
200 828 814 801 788 775 762 749 737 725 713
In Degrees F
APPENDIX - A
Sensor Resistance at Various Temperatures
Example: If temperature of sensor is 84°F, then the resistance through the sensor would be 8449 (see shaded area).
NOTE: Sensor resistance increases as the temperature falls.
Be Careful When Making Voltage Measurements or Jumping Terminals
Not to Damage or Deform Connectors or Connector Pins.
APPENDIX - B
Temperature Dial Resistance
Proper Readings Should Be Greater Then 4800 Ohms at
Minimum Setting
And Less Then 50 Ohms at Maximum.
Be Careful When Making Voltage Measurements or Jumping Terminals
Not to Damage or Deform Connectors or Connector Pins.
Draw Water From The T&P Valve. Compare Temperature With
Temperature Ohms Chart Below.
Page 13
SERVICE PROCEDURE EF-I
Thermostat Circuit Testing and Replacement
Page 13

Refer to ignition module
illustration, Is there 120VAC
between P1(1) and P1(3)?
Refer to ignition module
illustration, Is there
22 - 27VAC between
P2(1) and P2(2)?
Refer to ignition module
illustration, Is there 120VAC
between P7(3) and P7(1)?
Replace transformer.
(see pg 35)
Refer to ignition module
illustration, Is there 24VAC
between P3(9) and P2(1).
N
N
Y
Y
Check wire harness
continuity. Replace
thermostat sensor or wire
harness as necessary.
(see pg 17)
Check AC source to
determine why there is no
power.
Replace
ignition module.
(see pg 34)
N
Check continuity through
ECO, red wires of
thermostat sensor.
Check at temperature
less than 160°F
Is there continuity?
(see photo 6)
N
Replace ignition module.
(see pg 34)
Y
Replace thermostat
circuit board.
(see pg 15)
Y
N
Y
IGNITION MODULE
Thermostat circuit.
(continued from page 12)
6
Page 14
SERVICE PROCEDURE EF-I
Thermostat Circuit Testing and Replacement
WARNING
120 volt potential exposure. Use caution
making voltage checks to avoid personal injury.
Page 14

WARNING
120 volt potential exposure. Isolate the
appliance and reconfirm power is
disconnected using a multi-meter.
WIRING DIAGRAM
Thermostat
Board
Mounting
screw locations
Step 4. Locate thermostat board on control panel.
(see photo 7)
Step 5. Carefully disconnect all wires from thermostat
board.
Note: it may be necessary to identify
wires
for proper re-connection.
Step 6. Remove the two screws (Phillips head screw
driver) that secure thermostat board to
control panel.
Step 7. Install new thermostat board to control panel
using screws from step 6.
Step 8. Carefully reconnect wiring per the wire
diagram below. Reconfirm wire
connections are correct prior to putting
heater back in service
Step 9. Restore 120 volt power supply to water
heater and confirm proper operation following
the lighting instructions on the lighting
instruction label or the lighting instruction
located in the installation and operating
instruction manual.
Step 10. Replace surround cover on top of heater.
Thermostat Board Replacement Procedure
7
Page 15
SERVICE PROCEDURE EF-I
Thermostat Circuit Testing and Replacement
Step 1. Position main power switch to “OFF”
Step 2. Disconnect (unplug) water heater from 120
volt power source.
Step 3. Un-latch and remove top surround cover
from top of heater.
Page 15
WARNING
120 volt potential exposure. Isolate the
appliance and reconfirm power is
disconnected using a multi-meter.
WIRING DIAGRAM
Thermostat
Board
Mounting
screw locations
Step 4. Locate thermostat board on control panel.
(see photo 7)
Step 5. Carefully disconnect all wires from thermostat
board.
Note: it may be necessary to identify wires
for proper re-connection.
Step 6. Remove the two screws (Phillips head screw
driver) that secure thermostat board to
control panel.
Step 7. Install new thermostat board to control panel
using screws from step 6.
Step 8. Carefully reconnect wiring per the wire
diagram below. Reconfirm wire
connections are correct prior to putting
heater back in service
Step 9. Restore 120 volt power supply to water
heater and confirm proper operation following
the lighting instructions on the lighting
instruction label or the lighting instruction
located in the installation and operating
instruction manual.
Step 10. Replace surround cover on top of heater.
Thermostat Board Replacement Procedure
7
Page 15
SERVICE PROCEDURE EF-I
Thermostat Circuit Testing and Replacement
Step 1. Position main power switch to “OFF”
Step 2. Disconnect (unplug) water heater from 120
volt power source.
Step 3. Un-latch and remove top surround cover
from top of heater.

Thermostat Potentiometer Replacement Procedure
Step 4. Loosen set screw of adjusting
knob (small blade screw driver)
and remove adjusting knob
from potentiometer. (see photo 8)
Step 5. Remove retaining nut (½" wrench)
and washer from potentiometer.
(see photo 9)
Temperature
adjusting knob
Step 6. From inside of surround area, remove potentiometer
with gasket from side of surround. Notice how indexing
tab on potentiometer assembles into locating hole of
surround. (see photo 10)
Indexing
tab
Locating
hole
Step 7. Disconnect potentiometer wire leads.
(see photo 11)
Step 8. Install new potentiometer with gasket into side of surround. Be sure to assemble with
indexing tab inserted into locating hole on side of surround (see photo 10).
Step 9. Reconnect wires to potentiometer. Note: Wire leads are interchangeable with either wire.
Step 10. Restore 120 volt power supply to water heater and confirm proper operation following
the lighting instructions on the lighting instruction label or the lighting instruction located
in the installation and operating instruction manual.
Step 11. Replace surround cover on top of heater.
WARNING
120 volt potential exposure. Isolate the
appliance and reconfirm power is
disconnected using a multi-meter.
8
9
10
11
Page 16
SERVICE PROCEDURE EF-I
Thermostat Circuit Testing and Replacement
Step 1. Position main power switch to “OFF”
Step 2. Disconnect (unplug) water heater from
120 volt power source.
Step 3. Un-latch and remove top surround cover
from top of heater.
Page 16

Thermostat Sensor (Thermister) Replacement Procedure
Step 5. Fold back insulation just in front of burner to expose temperature sensor
(see photo 12).
WARNING
120 volt potential exposure. Isolate the
appliance and reconfirm power is
disconnected using a multi-meter.
Step 6. Disconnect temperature sensor from
harness (see photo 13).
Insulation folded
back to expose
temperature sensor
Step 7. Remove temperature sensor (1-1/16" hex, deep well socket) from heater.
Note: Using a deep well socket will allow room inside socket
for sensor connector and wires.
Disconnect sensor
from harness
Step 8. Apply Teflon tape or applicable thread lubricant to threads of new sensor. Install new
thermostat sensor and Connect to wire harness from step 6.
Step 9. Fold insulation back into place. Be sure there are no wires in contact with burner.
Step 10. Restore 120 volt power supply and water supply to water heater, check and repair any
leaks found. Confirm proper operation following the lighting instructions on the lighting
instruction label or the lighting instruction located in the installation and operating
instruction manual.
Step 11. Replace surround cover on top of heater.
12
13
Page 17
SERVICE PROCEDURE EF-I
Thermostat Circuit Testing and Replacement
Step 1. Position main power switch to “OFF”
Step 2. Disconnect (unplug) water heater from
120 volt power source.
Step 3. Drain heater down to a point below
the top of the tank.
Step 4. Un-latch and remove top surround cover
from top of heater.
Page 17

Does inlet gas pressure
drop more than 2" W.C.
during burner ignition?
Adjust gas
supply regulator
Inadequately
sized regulator.
Y
N
N
Y
N
Y
N
IGNITION MODULE
Verify Minimum Gas Supply Piping Requirements of:
Minimum ¾” NPT. (Schedule 40 black Iron Pipe
recommended).
Reconfigure gas
supply piping
Y
Observe burner operation through the sight glass located on the combustion insert mounting flange.
Normal burner operation should ignite smoothly, without evidence of coughing or huffing upon
ignition. The burner flame should be a blue flame near the burner surface in a uniform flame pattern.
Occasional yellow or white streaks are normal.
Inlet gas
pressure tap
Venturi
adjustment
14
Is igniter resistance
less than 150 Ohms
(cold)?
(see check igniter
illustration)
Refer to ignition module illustration below,
is there 120VAC across terminals
P6(1) and P6(2)?
(Note: Igniter LED must be lit during this check).
Y
NReplace
hot surface igniter.
(see pg 31)
Replace ignition
module.
(see pg 34)
N
Y
Do you see the igniter
glowing through burner
site glass during the
warm up period?
Proceed to page 19
With manometer, check inlet
gas pressure. Is it stable
between 7" & 14" W.C. static?
(heater not running)
(see illustration 14)
Is gas supply pressure
regulator adjustable to
maintain proper and
stable setting?
Y
N
Page 18
Volt meter set to
OHM setting
Meter probe
Hot surface
igniter
CHECK IGNITER
RESISTANCE
SERVICE PROCEDURE EF-II
Combustion System Testing and Replacement
WARNING
120 volt potential
exposure. Use caution
making voltage checks to
avoid personal injury.
WARNING
Removing screw from
inlet gas pressure tap will
immediately allow gas to
flow from pressure tap.
Page 18

Refer to ignition module illustration below,
is there 24VAC between P3(2) and P3(5) (blue and
brown wires) during the flame establishing period?
(Note: Valve LED must be lit during this check)
Y
Replace
ignition module.
(see pg 34)
N
Replace Rectifier
harness and/or
gas valve.
(see pg 24)
N
Y
Does flame LED on the module
light and stay lit?
Can you hear or feel
gas valve energize?
Does burner light
smoothly, without
evidence of coughing
or huffing?
Y
N
Check for obstruction
at inlet of gas valve.
Is inlet free of
obstruction?
Check flame sensor,
Is there 1 to 5 micro amps
during 1.5 second flame
proving period?
(see pg 32)
N
Y
IGNITION MODULE
Continued from
page 18
Inlet gas
pressure tap
Venturi
adjustment
16
N
Call for technical
support
Clear obstruction
Observe burner operation through the sight glass located on the combustion insert mounting flange.
Normal burner operation should ignite smoothly, without evidence of coughing or huffing upon
ignition. The burner flame should be a blue flame near the burner surface in a uniform flame pattern.
Occasional yellow or white streaks are normal.
Y
Does burner operate
normaly until thermostat is
satisfied?
N
System OK
Y
Page 19
SERVICE PROCEDURE EF-II
Combustion System Testing and Replacement
WARNING
120 volt potential exposure. Isolate the
appliance and reconfirm power is
disconnected using a multi-meter.
Turn VENTURI set screw
clockwise until its bottomed out.
Turn screw counter-clockwise
6-½ turns from bottom.
(see illustration 16)
Page 19
Refer to ignition module illustration below,
is there 24VAC between P3(2) and P3(5) (blue and
brown wires) during the flame establishing period?
(Note: Valve LED must be lit during this check)
Y
Replace
ignition module.
(see pg 34)
N
Replace Rectifier
harness and/or
gas valve.
(see pg 24)
N
Y
Does flame LED on the module
light and stay lit?
Can you hear or feel
gas valve energize?
Does burner light
smoothly, without
evidence of coughing
or huffing?
Y
N
Check for obstruction
at inlet of gas valve.
Is inlet free of
obstruction?
Check flame sensor,
Is there 1 to 5 micro amps
during 1.5 second flame
proving period?
(see pg 32)
N
Y
IGNITION MODULE
Continued from
page 18
Inlet gas
pressure tap
Venturi
adjustment
16
N
Call for technical
support
Clear obstruction
Observe burner operation through the sight glass located on the combustion insert mounting flange.
Normal burner operation should ignite smoothly, without evidence of coughing or huffing upon
ignition. The burner flame should be a blue flame near the burner surface in a uniform flame pattern.
Occasional yellow or white streaks are normal.
Y
Does burner operate
normaly until thermostat is
satisfied?
N
System OK
Y
Page 19
SERVICE PROCEDURE EF-II
Combustion System Testing and Replacement
WARNING
120 volt potential exposure. Isolate the
appliance and reconfirm power is
disconnected using a multi-meter.
Turn VENTURI set screw
clockwise until its bottomed out.
Turn screw counter-clockwise
6-½ turns from bottom.
(see illustration 16)
Replace flame sensor
(see page 33)

WARNING
120 volt potential exposure. Isolate the
appliance and reconfirm power is
disconnected using a multi-meter.
Step 1. Position main power switch to “OFF”.
Step 2. Disconnect (unplug) water heater from
120 volt power source.
Step 3. Turn off gas supply to water heater.
Step 4. Un-latch and remove surround cover from top of
heater.
Step 5. From the gas valve, disconnect the gas
connection, PVC venting, Silicone tubing
and wire harness.
Step 6. Disconnect wire harness’s from hot surface
igniter, flame sensor and blower.
Gas valve
wire harness
Gas
connection
PVC vent
connection
Burner mounting
insert
Burner mounting
screw
(Total of 5)
Step 7. Remove the 5 screws (½" socket)
holding the burner mounting insert
in place.
Step 8. Carefully remove combustion assembly
with gasket from water heater.
Step 9. See page 21 for combustion system installation procedure.
Combustion System Removal Procedure
Burner tube
WARNING
Heater components may be HOT when performing the following steps in this procedure.
Take necessary precaution to prevent personal injury.
Page 20
Burner mounting
insert gasket
SERVICE PROCEDURE EF-II
Combustion System Testing and Replacement
Page 20