L8104A,B,C,D
Electronic Water
Heater Controllers
L8104B with
Potentiometer
The L8104A,B,C,D Electronic Controllers pro-
vide temperature control and ECO limit action for
gas water heaters.
Remote
Potentiometer
Sensing
Bulb
■ L8104A,B are used in standing pilot and electronic
ignition systems.
■ L8104C,D are used only in electronic ignition sys-
tems.
■ Includeselectronicmodule,oneortwosensingbulbs,
and setpoint potentiometer (remote- or board-
mounted).
■ Sensing bulb contains thermistor sensor and ECO
switch. Second bulb in L8104B,C contains ther-
mistor only.
■ L8104A has single sensing bulb.
■ L8104B has two sensing bulbs available with upper
and lower bulb sensing authority allocated in ratios
of 1:1, 2:1, 3:1, and 4:1. Two sensing bulbs provide
temperature averaging.
■ Temperature range is factory-set to meet application
requirements.Maximumsettingtemperatureis200°F
(93°C).
■ ECO limit setting is factory-set to meet application
requirements.
■ For L8104A,B, standing pilot must be manually re-
lit or ignition module must be reset when ECO shuts
off gas control.
■ For L8104C,D, ignition module must be reset using
pushbutton switch mounted on electronic control
module when ECO shuts off gas control.
■ Control circuit is accurate within ±3.5°F (1.9°C) at
maximum setpoint (200°F [93°C]; setpoint controls
are accurate within +7°F [+3.8°C], -0°F [-0°C]).
■ L8104C has two sensing bulbs and manual reset
pushbutton.
■ L8104D has one sensing bulb and manual reset
pushbutton.
CONTENTS
Specifications ................................................. 2
Ordering Information ..................................... 2
Installation ..................................................... 5
Setting and Checkout.................................... 10
Operation ..................................................... 11
Troubleshooting ........................................... 12
Material Safety Data Sheets ......................... 15
J. H. • Rev. 6-95 • ©Honeywell Inc. 1995
68-0063-3
Download from Www.Somanuals.com. All Manuals Search And Download.
L8104A,B,C,D
SPECIFICATIONS
DIMENSIONS:
available through your Honeywell sales representative.
L8104: Fig. 1.
L8104A,B: Fig. 2.
L8104C,D: Fig. 3.
Please provide the ordering information indicated in the
Ordering Information section to assure correct replace-
ment components.
APPROVALS:
Underwriters Laboratories Inc. Component Recognized:
File No. MP466, Guide No. MBPR2.
AmericanGasAssociationCertified:ReportNo. 70-22A.
Canadian Gas Association Certified: Report No. 1029-
CC/T-6849.
Fig. 1—Approximate dimensions in in. (mm) of
L8104 Remote Potentiometer and Sensing Bulb.
REMOTE MOUNT POTENTIOMETER
3/4
(19)
OTHER SYSTEM COMPONENTS (Order separately):
5/32
15/16
(24)
3/8
(10)
(4)
3/8 DIA.
(10)
Electronic
Ignition
Module
System
Gas Control
1-1/16
(27)
1-3/8
(35)
Standing
pilot
—
VR800, VR8200, or any
rated 2.0A or less
3/8
(10)
1
3
2
FACTORY
INSTALLED
JUMPER
Intermittent S86F,H;
pilot
VR8440, VR8204 or
any rated 2.0A or less
1-1/4 (32)
S8600H;
S8610F,H
TERMINALS
1, 2 & 3
12 IN. (305 MM)
LEADWIRES
M413
REPLACEMENT PARTS: Replacement electronic control
modules, sensing bulbs, and remote potentiometers are
Fig. 2—Approximate dimensions in in. (mm) of L8104A,B Electronic Control Module.
L8104A,B ELECTRONIC CONTROL MODULE
2-15/32 (63)
1-15/16 (49)
3/4 (19)
1/4
(6)
(TWO)
1/4
(6)
(TWO)
1-1/8 (29)
9/32
(7)
3/8
(10)
1
1
1/2
(13)
4
4
2
UPPER
SEN-1
4
3-15/32
(88)
4
SEN-2
LOWER
2-15/16
(75)
COM.
4
3
24 V
HOT
RELAY
3
.170 DIA.
(FOUR)
ONLY
NO
3
1
2
MODELS WITH REMOTE POTENTIOMETER HAVE TWO 1/4 IN.
TAB TERMINALS IN PLACE OF THE POTENTIOMETER.
1
(25)
L8104A DOES NOT HAVE UPPER OR SEN-2 TERMINALS.
1/4 IN. TAB TERMINALS (3)
M113C
3
4
3/16 IN. TAB TERMINALS (5)
3
68-0063—3
Download from Www.Somanuals.com. All Manuals Search And Download.
L8104A,B,C,D
SPECIFICATIONS
ACCESSORIES:
L8104A:
L8104B:
198799A Sensor Assembly: 42 in. (107 cm) 125°C
4074ENP Potentiometer Assembly: 199075A Poten-
(257°F) leadwires with 1/4 in. quick connects.
198799B Sensor Assembly: 42 in. (107 cm) 150°C
(302°F) leadwires with 1/4 in. quick connects.
198799C Sensor Assembly: 42 in. (107 cm) 105°C
(221°F) leadwires with 1/4 in. quick connects.
198799D Sensor Assembly: 42 in. (107 cm) 105°C
(221°F) leadwires with 1/4 in. quick connects.
200636A Sensor Assembly: 180° F to 201°F (83°C to
94°C) cutoff temperature. 22 in. (56 cm) 150°C
(302°F) leadwires.
200636B Sensor Assembly: 180°F to 201°F (83°C to
94°C) cutoff temperature. 22 in. (56 cm) 150°C
(302°F) leadwires.
200636C Sensor Assembly: 180°F to 201°F (83°C to
94°C) cutoff temperature. 22 in. (56 cm) 150°C
(302°F) leadwires.
tiometer: Clockwise turn increases temperature,
two 18 in. [46 cm] leadwires with 1/4 in. quick
connects. Washer and nut.
4074ENS Potentiometer Assembly: 199053A Potenti-
ometer: Counterclockwise turn increases tempera-
ture, two 18in. (46cm) leadwireswithone barewire
and one 1/4 in. quick connect. Washer and nut.
198800AOne-ShotSensorAssembly(nonrecyclying):
189°F (87°C) cutoff temperature. 11 in. (28 cm)
sensor and ECO leadwires. Sensor leadwire is 1/4
in. quick connect. ECO leadwire is stripped.
198800B One-Shot Sensor Assembly (non recycling):
200°F (93°C) cutoff temperature. 11 in. (28 cm)
sensor and ECO leadwires. Sensor leadwire is 1/4
in. quick connect. ECO leadwire is stripped.
198799B Sensor Assembly: 42 in. (107 cm) 150°C
(302°F) leadwires with 1/4 in. quick connects.
200650APotentiometer:Clockwiseturnincreasestem-
perature. 8 in. (20 cm) leadwires with two 1/4 in.
quick connects.
Fig. 3—Approximate dimensions in in. (mm) of L8104C,D Electronic Control Module.
2-7/16 (62)
1-61/64 (50)
1/4
(6)
(TWO)
1/4
(6)
(TWO)
1-1/8 (29)
9/32
(7)
1 (25)
19/32
(15)
1
1
1/2
(13)
3/16 IN. TAB
TERMINALS
SEN-1
UPPER
SEN-2
4-23/64
(111)
LOWER
2-61/64
(75)
U1
(TWO)
COM.
24V
.170 DIA. (FOUR)
K1
1/4 IN.TAB
TERMINALS
C1
PV
ECO
LOAD
K2
LOCKOUT
INDICATOR
LIGHT
ECO
VALVE
PUSH BUTTON RESET
MODELS WITH REMOTE POTENTIOMETER HAVE TWO
1 (25)
1
1/4 IN. TAB TERMINALS IN PLACE OF THE POTENTIOMETER.
M414
68-0063—3
4
Download from Www.Somanuals.com. All Manuals Search And Download.
L8104A,B,C,D
INSTALLATION
Installation
WHEN INSTALLING THIS PRODUCT…
1. Read these instructions carefully. Failure to follow
them could damage the product or cause a hazardous
condition.
2. Check the ratings given in the instructions and on
the product to make sure the product is suitable for your
application.
Electronic Control Module
Locate the electronic control module on a wall or panel
in the wiring compartment of the water heater. The module
must be within easy reach of the sensor leadwires in a
location that is convenient for reading and changing the
temperature setting. Choose a location where the module
will not be exposed to water. An enclosure is recommended
to help protect the module. Mount the module with four no.
6 or 8 screws through the corner standoffs.
3. Installer must be a trained, experienced service
technician.
4. After installation is complete, check out product
operation as provided in these instructions.
Remote Mount Potentiometer
Choose a location that is convenient for reading and
changing the temperature setting. Mount the potentiometer
from the back of a panel through a 3/8 in. hole and secure it
with a nut on the threaded shaft.
WARNING
EXPLOSION HAZARD.
CAN CAUSE PROPERTY DAMAGE,
SEVERE INJURY OR DEATH.
This product is for use only in a system with a
pressure relief valve.
WIRING
IMPORTANT: For maximum trouble free operation, run
the sensing bulb leadwires separately from any other
current-carrying wires.
CAUTION
All wiring must comply with local codes and ordi-
nances. Disconnect power supply before beginning wiring.
Connect according to water heater manufacturer instruc-
tions, if available, or use Fig. 5 through 10 as a guide.
Disconnect power supply before wiring to prevent
electrical shock or equipment damage.
IMPORTANT: Do not bend or pull on sensor leadwires
whentemperatureisbelowfreezingtopreventleadwire
damage.InstallL8104onlywhentemperatureisabove
32°F (0°C).
Fig. 4—Possible location of thermistor/ECO
bulb and thermistor bulb.
LOCATION AND MOUNTING
Sensing Bulb(s)
L8104B, C
L8104A, D
The water heater manufacturer usually provides a tap-
ping for the sensing bulb at a point where average water
temperature can be measured. With L8104B,C, the bulb
containingthethermistorandECOswitchisusuallymounted
in the tapping near the bottom of the heater, and the other
bulb is located near the top. See Fig. 4. Follow the heater
manufacturer instructions.
UPPER
SENSING BULB
(WITHOUT ECO)
ELECTRONIC
CONTROL
MODULE
ENCLOSURE
ELECTRONIC
CONTROL
MODULE
ENCLOSURE
The sensing bulb can be installed in an immersion well
or directly immersed with a suitable compression fitting to
prevent leakage. Wells and fittings must be ordered sepa-
rately.
LOWER
SENSING BULB
(WITH ECO)
SENSING
BULB
(WITH ECO)
If an immersion well is used, the bulb should fit snugly
and should touch the bottom of the well for best temperature
response. Use heat-conductive compound (available in 4 oz
can as Honeywell part no. 107408) to fill the space between
the bulb and the well and improve heat transfer characteris-
tics. Make sure the bulb is held firmly in the well.
If the sensor is directly immersed, use a 3/8 in. x 1/2 in.
compression to M.I.P. coupling or O-ring and clamp to
prevent leaks and keep bulb leadwires dry.
THERMOCOUPLE
AND PILOT
BURNER
MAIN
BURNER
MAIN
BURNER
THERMOCOUPLE
AND PILOT BURNER
M132A
5
68-0063—3
Download from Www.Somanuals.com. All Manuals Search And Download.
L8104A,B,C,D
INSTALLATION
Fig. 5—L8104A with board-mounted potentiometer in a standing pilot application.
L8104A
BLACK
BLACK
3
3
SEN-1
SENSING BULB WITH
ECO SWITCH
LOWER
COM.
2
3
24V
HOT
RELAY
2
Q308
ONLY
NO
2
ECO
CONNECTOR
1
POWER SUPPLY. PROVIDE DISCONNECT
MEANS AND OVERLOAD PROTECTION
AS REQUIRED.
VR8200
GAS VLAVE
TH
TR
2
3
1/4 IN. TAB TERMINALS (3).
1
L1
(HOT)
3/16 IN. TAB TERMINALS (3).
M131C
L2
24V
Fig. 6—L8104A with remote potentiometer in an electronic ignition application.
1
L8104A
SETPOINT
POTENTIOMETER
(SHOWN FROM BACK)
2
3
3
POT
BLACK
BLACK
5
SEN-1
SENSING BULB WITH
ECO SWITCH
5
LOWER
COM.
4
5
24V
RELAY
PILOT
VALVE
MAIN
VALVE
HOT
COM
4
ONLY
NO
4
VR8440 OR
1ST
2ND
VR844
2
OPERATOR OPERATOR
S8600F,H,M;
S8610F,H
1
2
POWER SUPPLY. PROVIDE DISCONNECT
MEANS AND OVERLOAD PROTECTION
AS REQUIRED.
VENT
DAMPER
GND
24V
TH-W
MV MV/PV PV (BURNER) GND 24V (OPT) PLUG (OPT)
SPARK
TERMINAL DESIGNATIONS
GAS CONTROL
PILOT
COM
MAIN
VR844, VR8440
TH
TH-TR
TR
3
FACTORY INSTALLED JUMPER; DO NOT
REMOVE.
1
L1
(HOT)
24V
4
5
1/4 IN. TAB TERMINALS (3).
3/16 IN. TAB TERMINALS (3).
L2
M128B
68-0063—3
6
Download from Www.Somanuals.com. All Manuals Search And Download.
L8104A,B,C,D
INSTALLATION
Fig. 7—L8104B with remote potentiometer in a standing pilot application.
1
SETPOINT
POTENTIOMETER
(SHOWN FROM BACK)
2
L8104B
2
3
POT
UPPER
SEN-2
BLACK
BLACK
BLACK
BLACK
4
4
4
SEN-1
SENSING BULB WITH
ECO SWITCH
4
SENSING BULB
LOWER
COM.
4
3
24V
HOT
RELAY
3
Q308
NO
3
ONLY
1
2
POWER SUPPLY. PROVIDE DISCONNECT
MEANS AND OVERLOAD PROTECTION
AS REQUIRED.
ECO
CONNECTOR
FACTORY JUMPER INSTALLED, DO NOT
REMOVE.
VR8200
GAS VLAVE
TH
TR
1/4 IN. TAB TERMINALS (3).
3
4
1
L1
3/16 IN. TAB TERMINALS (5).
M130C
(HOT)
24V
L2
Fig. 8—L8104B with board-mounted potentiometer in an electronic ignition application.
L8104B
UPPER
BLACK
BLACK
BLACK
BLACK
4
4
SEN-2
4
SEN-1
SENSING BULB WITH
ECO SWITCH
4
SENSING BULB
LOWER
COM.
4
3
24V
HOT
RELAY
PILOT
VALVE
MAIN
VALVE
COM
3
ONLY
NO
3
VR8440 OR
1ST
2ND
VR844
2
OPERATOR OPERATOR
S8600F,H,M;
S8610F,H
VENT
1
2
POWER SUPPLY. PROVIDE DISCONNECT
MEANS AND OVERLOAD PROTECTION
AS REQUIRED.
GND
24V
TH-W
DAMPER
MV MV/PV PV (BURNER) GND 24V (OPT) PLUG (OPT)
SPARK
TERMINAL DESIGNATIONS
GAS CONTROL
PILOT
COM
MAIN
VR844, VR8440
TH
TH-TR
TR
3
4
1/4 IN. TAB TERMINALS (3).
3/16 IN. TAB TERMINALS (5).
1
L1
M129B
(HOT)
24V
L2
7
68-0063—3
Download from Www.Somanuals.com. All Manuals Search And Download.
L8104A,B,C,D
INSTALLATION
Fig. 9—L8104C with remote-mounted potentiometer in an electronic ignition application.
S8600H
VENT
5
DAMPER
PLUG
GND
24V
TH-W
MV MV/PV PV (BURNER) GND 24V (OPT)
SPARK
(OPT)
5
MAIN
VALVE
COM
PILOT
1ST
BLACK
BLACK
DUAL VALVE
2ND
COMBINAITON
GAS CONTROL
OPERATOR OPERATOR
SENSING BULB
1
2
L8104C
3
2
POT
SETPOINT
POTENTIOMETER
(SHOWN FROM BACK)
BLACK
BLACK
SEN-1
UPPER
SEN-2
SENSING BULB
WITH ECO SWITCH
LOWER
L1
(HOT)
COM.
24V
4
L2
1
Q345, Q346, Q348,
Q362, Q381
PILOT BURNER/
IGNITER-SENSOR
PILOT
BURNER
GROUND
LOAD
PV
ECO
PILOT GAS
3
SUPPLY
ECO
VALVE
CONTROLS IN 24V CIRCUIT MUST NOT BE IN GROUND LEG
TO TRANSFORMER.
POWER SUPPLY. PROVIDE DISCONNECT MEANS
AND OVERLOAD PROTECTION AS REQUIRED.
4
5
1
FOR S8600H WITH TH-W TERMINAL AND VENT DAMPER PLUG,
CONNECT THERMOSTAT TO TH-W. LEAVE 24V OPEN.
FACTORY INSTALLED JUMPER. DO NOT REMOVE.
MAXIMUM CABLE LENGTH 3 FT. (0.9M).
2
3
DO NOT REMOVE VENT DAMPER PLUG.
M417
68-0063—3
8
Download from Www.Somanuals.com. All Manuals Search And Download.
L8104A,B,C,D
INSTALLATION
Fig. 10—L8104D with remote-mounted potentiometer in an electronic ignition application
S8600H
VENT
5
DAMPER
GND
24V
TH-W
PLUG
(OPT)
MV MV/PV PV (BURNER) GND 24V (OPT)
SPARK
5
MAIN
VALVE
COM
PILOT
1ST
DUAL VALVE
2ND
COMBINATION
GAS CONTROL
OPERATOR OPERATOR
1
2
L8104D
3
2
POT
SETPOINT
POTENTIOMETER
(SHOWN FROM BACK)
BLACK
BLACK
SEN-1
SENSING BULB
WITH ECO SWITCH
LOWER
L1
(HOT)
COM.
24V
4
L2
1
Q345, Q346, Q348,
Q362, Q381
PILOT BURNER/
IGNITER-SENSOR
PILOT
BURNER
GROUND
LOAD
PV
ECO
PILOT GAS
3
SUPPLY
ECO
VALVE
CONTROLS IN 24V CIRCUIT MUST NOT BE IN GROUND LEG
TO TRANSFORMER.
POWER SUPPLY. PROVIDE DISCONNECT MEANS
AND OVERLOAD PROTECTION AS REQUIRED.
4
5
1
FOR S8600H WITH TH-W TERMINAL AND VENT DAMPER PLUG,
CONNECT THERMOSTAT TO TH-W. LEAVE 24V OPEN.
FACTORY INSTALLED JUMPER. DO NOT REMOVE.
MAXIMUM CABLE LENGTH 3 FT. (0.9M).
2
3
DO NOT REMOVE VENT DAMPER PLUG.
M415
9
68-0063—3
Download from Www.Somanuals.com. All Manuals Search And Download.
L8104A,B,C,D
SETTING AND CHECKOUT
Setting and Checkout
SET CONTROL TEMPERATURE
If the potentiometer is mounted on the control module,
turn the selector knob to the desired temperature.
If the potentiometer is remotely mounted, the position of
the flat part of the shaft determines the approximate control
temperature. Fully counterclockwise
the shaft is towards you is the minimum setting. Fully
clockwise rotation is the maximum setting. Actual
Fig. 11—Scale range for 3K remotely mounted
potentiometer when used with L8104B Dual
Bulb Controller.
200650 POTENTIOMETER
rotation when
180oF
90oF
temperature range depends on the control module and the
potentiometer selected. See Fig. 11.
CHECKOUT
Set the L8104 above water temperature and observe the
system through one complete cycle. Make sure system
operates as desired.
To check the thermistor or thermistor/ECO assembly,
compare its resistance as measured by an ohmmeter to the
water temperature as measured by an accurate thermom-
eter. Thermistor resistance increases as the temperature
falls. See Table 1 or 2 for the correct sensor resistance at
various temperatures.
135oF
3
2
1
MAXIMUM SETTING AT
FULLY CLOCKWISE
POSITION
M133A
TABLE 1—THERMISTOR RESISTANCE AT VARIOUS TEMPERATURES IN FAHRENHEIT.
Temp-
erature
(°F)
Resistance (K ohms)
0
1
2
3
4
5
6
7
8
9
40
50
60
70
80
26109
19906
15314
11884
9299
7333
5827
4663
3758
3048
2488
2043
1688
1402
1170
982
25400
19383
14925
11592
9078
7165
5697
4562
3679
2986
2439
2004
1656
1376
1150
965
24712
18876
14548
11308
8862
7000
5570
4464
3602
2925
2391
1966
1625
1351
1129
949
24045
18383
14180
11032
8653
6839
5446
4368
3527
2866
2344
1928
1595
1327
1110
933
23399
17905
13823
10763
8449
6683
5326
4274
3453
2808
2298
1891
1566
1303
1090
917
22771
17440
13477
10502
8250
6531
5208
4183
3382
2752
2253
1856
1537
1280
1071
901
22163
16990
13140
10248
8057
6383
5094
4094
3312
2697
2209
1820
1509
1257
1053
886
21573
16553
12812
10000
7869
6238
4982
4006
3244
2643
2166
1786
1481
1235
1035
871
21000
16128
12494
9760
7685
6098
4873
3922
3177
2590
2124
1753
1454
1213
1017
857
20445
15715
12185
9526
7507
5961
4767
3839
3112
2538
2083
1720
1427
1191
999
90
100
110
120
130
140
150
160
170
180
190
200
842
828
814
801
788
775
762
749
737
725
713
68-0063—3
10
Download from Www.Somanuals.com. All Manuals Search And Download.
L8104A,B,C,D
SETTING AND CHECKOUT • OPERATION
TABLE 2—THERMISTOR RESISTANCE AT VARIOUS TEMPERATURES IN CELSIUS.
Temp-
erature
(°C)
Resistance (K ohms)
0
1
2
3
4
5
6
7
8
9
0
10
20
30
40
50
60
70
80
90
32648
19898
12492
8057
5327
3602
2488
1752
1256
916
31026
18968
11942
7722
5117
3468
2400
1693
1216
888
29495
18088
11419
7403
4917
3340
2316
1637
1177
861
28049
17253
10922
7099
4726
3217
2235
1582
1140
835
26682
16461
10450
6808
4543
3099
2157
1530
1105
810
25389
15710
10000
8532
4368
2986
2083
1480
1070
786
24166
14998
9572
6268
4201
2878
2011
1432
1037
763
23010
14322
9165
6016
4042
2774
1942
1385
1005
741
21915
13680
8778
5775
3889
2675
1876
1340
974
20879
13071
8409
5546
3742
2579
1813
1297
944
719
698
Operation
L8104A,D
L8104A,B
The L8104A,B uses a recycling ECO switch that re-
When the temperature at the sensing bulb drops below
the setting on the potentiometer, the relay contacts in the
electronic control module make to open the gas control or
turn on the ignition module. When the temperature rises to
the setpoint, the relay contacts open, closing the gas control
or turning off the ignition module.
The control circuit is accurate to within ±3.5°F (±1.9°C)
at maximum setpoint. (180°F (83°C) setpoint controls are
accurate within +7°F (+3.8°C), -0°F (0°C).
makes once the temperature drops below the ECO tempera-
ture. Before the system will restart, however, the system
must be reset. On a standing pilot system, the pilot must be
relit. On an electronic ignition system, power to the 100
percent lockout ignition module must be off for one minute.
A nonrecycling (one-shot) ECO switch will not remake.
The sensing bulb containing the switch must be replaced.
L8104C,D
L8104B,C
The L8104C,D uses a recycling ECO switch. When the
ECO opens, the red LED on the electronic module lights
and the water heater is turned off. To restart the system,
press the black manual reset pushbutton until the red LED
turns off. The ECO switch is closed and the sys-
tem is reset.
Operation of the L8104B,C is similar to L8104A,D ex-
cept the electronic control module opens and closes the
relay in response to the average of the temperatures sensed
by the upper and lower sensing bulbs.
ECO LIMIT OPERATION
If the temperature at the ECO switch rises above the
ECO limit setting, the contacts in the ECO switch break and
turn off the water heater.
11
68-0063—3
Download from Www.Somanuals.com. All Manuals Search And Download.
L8104A,B,C,D
TROUBLESHOOTING
Troubleshooting
If water temperature is too hot, proceed as follows:
L8104A, B, C, D
START
DISCONNECT SENSOR LEADS FROM ELECTRONIC
CONTROL MODULE AND MEASURE RESISTANCE OF
SENSOR(S) WITH OHMMETER.
IS RESISTANCE BETWEEN 700K AND 30K OHMS
(SEE TABLE 1)?
NO
SENSOR(S) MAY BE SHORTED OR OPEN.
CHECK FOR LOOSE, BROKEN OR SHORTED WIRES.
REPLACE SENSING BULB(S) IF NECESSARY.
YES
SENSOR(S) OK. DISCONNECT ECO LEADS AND
MEASURE RESISTANCE WITH OHMMETER. IS WATER
TEMPERATURE GREATER THAN 210˚F AND ECO
RESISTANCE LESS THAN 10 OHMS (SHORTED)?
YES
NO
REPLACE SENSING BULB WITH ECO LIMIT AND
CHECK OUT BALANCE OF SYSTEM.
NO
REPLACE ELECTRONIC CONTROL MODULE.
RECONNECT ALL LEADS AND CHECK OUT SYSTEM.
IS THE POTENTIOMETER REMOTE?
YES
DISCONNECT POTENTIOMETER LEADS FROM
ELECTRONIC CONTROL MODULE. MEASURE
RESISTANCE OF POTENTIOMETER WITH OHMMETER.
IS RESISTANCE GREATER THAN 1000 OHMS AT MINIMUM
TEMPERATURE SETTING (CHECKS FOR SHORT)?
NO
REPLACE POTENTIOMETER.
RECONNECT ALL LEADS AND CHECK OUT SYSTEM.
YES
POTENTIOMETER OK. REPLACE ELECTRONIC CONTROL
MODULE. RECONNECT ALL LEADS AND CHECK OUT
SYSTEM.
M134B
68-0063—3
12
Download from Www.Somanuals.com. All Manuals Search And Download.
L8104A,B,C,D
TROUBLESHOOTING
If water temperature is too cold or heater does not come on, proceed as follows:
L8104A, B
START
CHECK VOLTAGE AT 24V TERMINALS
OF ELECTRONIC CONTROL MODULE.
NO
CHECK TRANSFORMER, 120V SUPPLY,
CORRECT AS NECESSARY.
IS VOLTAGE BETWEEN 21.5 AND
28.5 VAC?
YES
IS THIS AN ELECTRONIC IGNITION
SYSTEM WITH 100 PERCENT LOCKOUT?
YES
DISCONNECT 24V POWER AT IGNITION
MODULE AND RECONNECT AFTER
ABOUT 1 MIN. SET POTENTIOMETER TO
MAX TEMPERATURE SETTING.
YES
IGNITION MODULE WAS IN LOCKOUT.
OBSERVE FOR 2-3 CYCLES TO MAKE
SURE SYSTEM IS OTHERWISE OK.
DOES HEATER TURN ON?
NO
NO
REPLACE SENSING BULB WITH ECO
SWITCH AND OBSERVE SYSTEM IN
OPERATION. IF WATER HEATER DOES
NOT TURN OFF AFTER WATER
REACHES SET POINT TEMPERATURE,
REFER TO TROUBLESHOOTING IF
WATER IS TOO HOT.
DISCONNECT ECO LEADS AND MEASURE
RESISTANCE WITH OHMMETER.
YES
IS RESISTANCE GREATER THAN
100K OHMS (OPEN)?
NO
DISCONNECT SENSOR LEADS FROM
ELECTRONIC CONTROL MODULE AND
MEASURE RESISTANCE OF SENSOR(S)
WITH OHMMETER.
SENSOR(S) MAY BE SHORTED OR
OPEN. CHECK FOR LOOSE, BROKEN
OR SHORTED WIRES. REPLACE
SENSING BULB(S) IF NECESSARY.
NO
IS RESISTANCE BETWEEN 700 AND
30K OHMS (SEE TABLE 1)?
YES
REPLACE ELECTRONIC CONTROL
MODULE. RECONNECT ALL LEADS
AND CHECK OUT SYSTEM.
NO
NO
SENSORS OK. IS THE POTENTIOMETER
REMOTE?
YES
DISCONNECT POTENTIOMETER LEADS FROM
ELECTRONIC CONTROL MODULE. MEASURE
RESISTANCE OF POTENTIOMETER WITH
OHMMETER.
REPLACE POTENTIOMETER.
RECONNECT ALL LEADS AND CHECK
OUT SYSTEM.
IS RESISTANCE GREATER THAN 1000 OHMS AT
MINIMUM TEMPERATURE SETTING AND LESS
THAN 50 OHMS AT MAXIMUM TEMPERATURE
SETTING (CHECKS FOR OPEN OR SHORTS)?
YES
POTENTIOMETER OK. REPLACE ELECTRONIC
CONTROL MODULE. RECONNECT ALL LEADS
AND CHECK OUT SYSTEM.
M135B
13
68-0063—3
Download from Www.Somanuals.com. All Manuals Search And Download.
L8104A,B,C,D
TROUBLESHOOTING
L8104C, D
YES
SYSTEM SHUT DOWN DUE TO ECO
OPENING.
IS LED LIT?
DEPRESS AND RELEASE MANUAL
RESET BUTTON.
NO
NO
DOES LED TURN OFF?
CHECK VOLTAGE AT 24V TERMINALS
OF ELECTRONIC CONTROL MODULE.
YES
NO
CHECK TRANSFORMER, 120V SUPPLY,
CORRECT AS NECESSARY.
IS VOLTAGE BETWEEN 21.5 AND
28.5 VAC?
SYSTEM RESET.
YES
REFER TO TROUBLESHOOTING IF
WATER IS TOO HOT.
IS THIS AN ELECTRONIC IGNITION
SYSTEM WITH 100 PERCENT LOCKOUT?
YES
DISCONNECT 24V POWER AT IGNITION
MODULE AND RECONNECT AFTER
ABOUT 1 MIN. SET POTENTIOMETER TO
MAX TEMPERATURE SETTING.
IGNITION MODULE WAS IN LOCKOUT.
OBSERVE FOR 2-3 CYCLES TO MAKE
SURE SYSTEM IS OTHERWISE OK.
YES
DISCONNECT ECO LEADS AND MEASURE
RESISTANCE WITH OHMMETER.
DOES HEATER TURN ON?
IS RESISTANCE GREATER THAN 100K
OHMS WITH WATER TEMPERATURE LESS
THAN 180°F?
NO
NO
YES
DISCONNECT ECO LEADS AND MEASURE
RESISTANCE WITH OHMMETER.
NO
YES
REPLACE SENSING BULB WITH ECO
SWITCH.
IS RESISTANCE GREATER THAN
100K OHMS (OPEN)?
REPLACE SENSING BULB WITH
ECO SWITCH.
NO
DISCONNECT SENSOR LEADS FROM
ELECTRONIC CONTROL MODULE AND
MEASURE RESISTANCE OF SENSOR(S)
WITH OHMMETER.
SENSOR(S) MAY BE SHORTED OR
OPEN. CHECK FOR LOOSE, BROKEN
OR SHORTED WIRES. REPLACE
SENSING BULB(S) IF NECESSARY.
NO
IS RESISTANCE BETWEEN 700K AND 30K
OHMS (SEE TABLE 1)?
REPLACE ELECTRONIC CONTROL MODULE.
RECONNECT ALL LEADS AND CHECK OUT
SYSTEM.
YES
REPLACE ELECTRONIC CONTROL
MODULE. RECONNECT ALL LEADS
AND CHECK OUT SYSTEM.
NO
NO
SENSORS OK. IS THE POTENTIOMETER
REMOTE?
YES
DISCONNECT POTENTIOMETER LEADS FROM
ELECTRONIC CONTROL MODULE. MEASURE
RESISTANCE OF POTENTIOMETER WITH
OHMMETER.
REPLACE POTENTIOMETER.
RECONNECT ALL LEADS AND CHECK
OUT SYSTEM.
IS RESISTANCE GREATER THAN 500 OHMS AT
MINIMUM TEMPERATURE SETTING AND LESS
THAN 100 OHMS AT MAXIMUM TEMPERATURE
SETTING (CHECKS FOR OPEN OR SHORTS)?
YES
POTENTIOMETER OK. REPLACE ELECTRONIC
CONTROL MODULE. RECONNECT ALL LEADS
AND CHECK OUT SYSTEM.
M416A
68-0063—3
14
Download from Www.Somanuals.com. All Manuals Search And Download.
L8104A,B,C,D
MATERIAL SAFETY DATA SHEET
15
68-0063—3
Download from Www.Somanuals.com. All Manuals Search And Download.
L8104A,B,C,D
MATERIAL SAFETY DATA SHEET
68-0063—3
16
Download from Www.Somanuals.com. All Manuals Search And Download.
L8104A,B,C,D
MATERIAL SAFETY DATA SHEET
17
68-0063—3
Download from Www.Somanuals.com. All Manuals Search And Download.
L8104A,B,C,D
MATERIAL SAFETY DATA SHEET
68-0063—3
18
Download from Www.Somanuals.com. All Manuals Search And Download.
L8104A,B,C,D
MATERIAL SAFETY DATA SHEET
19
68-0063—3
Download from Www.Somanuals.com. All Manuals Search And Download.
L8104A,B,C,D
MATERIAL SAFETY DATA SHEET
Home and Building Control
Honeywell Inc.
1985 Douglas Drive North
Golden Valley, MN 55422
Home and Building Control
Honeywell Limited—Honeywell Limitée
740 Ellesmere Road
Helping You Control Your World
Scarborough, Ontario
M1P 2V9
Printed in U.S.A.
customer.honeywell.com
Download from Www.Somanuals.com. All Manuals Search And Download.
|