Frymaster GBC User Manual
GSMS, GBC and GC
Gas Cooker Models
(Including GSW and GWB Variants)
Service and Parts Manual
Frymaster, a member of the Commercial Food Equipment Service Association, recommends
using CFESA Certified Technicians.
24-Hour Service Hotline 1-800-551-8633
819-5312
AUG 2009
DANGER
IMPROPER INSTALLATION, ADJUSTMENT, ALTERATION, SERVICE, OR
MAINTENANCE CAN CAUSE PROPERTY DAMAGE, INJURY, OR DEATH. READ THE
INSTALLATION, OPERATING, AND SERVICE INSTRUCTIONS THOROUGHLY BEFORE
INSTALLING OR SERVICING THIS EQUIPMENT.
DANGER
FOR YOUR SAFETY, DO NOT STORE OR USE GASOLINE OR OTHER FLAMMABLE
LIQUIDS OR VAPORS IN THE VICINITY OF THIS OR ANY OTHER APPLIANCE.
DANGER
POST IN A PROMINENT LOCATION THE INSTRUCTIONS TO BE FOLLOWED IN THE
EVENT THE USER SMELLS GAS. THIS INFORMATION SHALL BE OBTAINED BY
CONSULTING THE LOCAL GAS SUPPLIER.
THIS EQUIPMENT IS TO BE INSTALLED IN COMPLIANCE WITH THE BASIC PLUMBING
CODE OF THE BUILDING OFFICIALS AND CODE ADMINISTRATORS INTERNATIONAL,
INC. (BOCA) AND THE FOOD SERVICE SANITATION MANUAL OF THE FOOD AND
DRUG ADMINISTRATION.
COMPUTERS
FCC
This device complies with Part 15 of the FCC rules. Operation is subject to the following two conditions:
1) This device may not cause harmful interference, and 2) This device must accept any interfere nce
received, including interference that may cause undesired operation. While this device is a verified Class
A device, it has been shown to meet the Class B limits.
CANADA
This digital apparatus does not exceed the Class A or B limits for radio noise emissions as set out by the
ICES-003 standard of the Canadian Department of Communications.
Cet appareil numerique n’emet pas de bruits radioelectriques depassany les limites de classe A et B
prescrites dans la norme NMB-003 edictee par le Ministre des Communcations du Canada.
DANGER
THIS PRODUCT CONTAINS CHEMICALS KNOWN TO THE STATE OF CALIFORNIA TO
CAUSE CANCER AND/OR BIRTH DEFECTS OR OTHER REPRODUCTIVE HARM.
Operation, installation, and servicing of this product could expose you to airborne
particles of glasswool or ceramic fibers, crystalline silica, and/or carbon monoxide.
Inhalation of airborne particles of glasswool or ceramic fibers is known to the State of
California to cause cancer. Inhalation of carbon monoxide is known to the State of
California to cause birth defects or other reproductive harm.
FRYMASTER FRYERS EQUIPPED WITH LEGS ARE FOR PERMANENT INSTALLATION.
FOR MOVEABLE OR PORTABLE INSTALLATION, FRYMASTER OPTIONAL EQUIPMENT
CASTERS MUST BE USED.
QUESTIONS??? CALL 1-800-551-8633.
Do not use deliming solution to clean water bath units. Use of deliming solution will damage all stainless
steel parts.
GAS COOKERS GSMS, GBC AND GC
SERVICE & PARTS MANUAL
TABLE OF CONTENTS
CHAPTER 1: Service Procedures
1.1 Functional Description.......................................................................................................1-1
1.2 Accessing Equipment for Servicing...................................................................................1-2
1.3 Replacing Equipment Components....................................................................................1-3
1.3.1 Replacing the Controller................................................................................................1-3
1.3.2 Replacing Electronic Components Other than the Controller.......................................1-3
1.3.3 Replacing a Water-Level Sensor or the Temperature Probe.........................................1-4
1.3.4 Replacing the Pressure Regulator or Solenoid Valve....................................................1-5
1.3.5 Replacing the Water Faucet...........................................................................................1-5
1.3.6 Replacing a Basket Lift Motor or Microswitch.............................................................1-6
1.3.7 Replacing Gas Supply System Components or Ignitor Assemblies..............................1-7
1.3.8 Replacing the Cookpot or Rinse Tank...........................................................................1-8
1.4 Troubleshooting.................................................................................................................1-9
1.4.1 How the Power Supply System Works .........................................................................1-9
1.4.2 How the Controller Works ............................................................................................1-9
1.4.3 How the Autofill/Autoskim System Works ................................................................1-10
1.4.4 How the Water Heating System Works.......................................................................1-10
1.4.5 How the Basket Lift System Works............................................................................1-11
1.4.6 Technician Troubleshooting Guides............................................................................1-11
1.4.7 Probe Resistance Chart and Wiring Diagrams............................................................1-15
CHAPTER 2: Parts List
2.1 Accessories ........................................................................................................................2-1
2.2 Basket Lift Components ....................................................................................................2-2
2.3 Cabinetry............................................................................................................................2-4
2.4 Combustion System Components......................................................................................2-8
2.5 Control Box and Related Components ............................................................................2-10
2.6 Controllers and Control Panel Components ....................................................................2-12
2.7 Cookpot, Rinse Tank and Associated Components.........................................................2-13
2.8 Drain Components ...........................................................................................................2-15
2.9 Gas Supply System Components.....................................................................................2-16
2.10 Water Supply Components..............................................................................................2-18
Appendix A: Notes Concerning and Parts Unique to GSW/GWB Variants
Accessories..................................................................................................................................A-1
Control Components....................................................................................................................A-2
Service Cookpot ..........................................................................................................................A-3
Water Supply Components..........................................................................................................A-4
Wiring Diagrams.........................................................................................................................A-6
i
GAS COOKERS GSMS, GBC, AND GC SERVICE AND PARTS
CHAPTER 1: SERVICE PROCEDURES
1.1 Functional Description
The GSMS, GBC, and GC Gas Cookers all have a 12.7-gallon (48.1-liter) stainless steel cookpot.
The water in the cookpot is heated by a high-efficiency infrared heating system that requires
approximately 43% less energy than conventional burner systems to heat the same volume of water.
Two self-contained combustion chambers (commonly referred to as burners) are located beneath the
cookpot. Each combustion chamber is fitted with special ceramic tiles that are heated by the burning
of a forced air/gas mixture. The tiles transfer their heat to the cookpot by means of infrared
radiation, providing much more constant and uniform heat dispersion over the surface of the cookpot
than do conventional burners. Because relatively less heat is lost to the atmosphere in the process,
compared to “open-burner” designs, less fuel is required to achieve and maintain a given cookpot
temperature.
Gas flow to both of the burners is regulated by one electromechanical gas valve.
Operational control of the burner system is accomplished through a solid-state SMS III Spaghetti
Magic controller. NOTE: The SMS III controller used in this model series is identical in
appearance to the SMS III controllers used in other model series, but differs internally. Use only the
part numbers listed in Chapter 2 when replacing controllers on this equipment. The GSMS is
equipped with a basket lift, and also features automatic filling (Autofill), automatic skimming
(Autoskim), a swing-away jointed faucet, and an attached 16.5-gallon (62.5-liter) rinse-tank. The
GBC model is identical to the GSMS except that it does not have the swing-away faucet and
attached rinse-tank. The GC has no basket lift, no faucet, and no rinse tank.
When the controller Power switch is pressed, a logic circuit in the controller automatically checks
the water level in the cookpot. A normally closed solenoid valve on the water supply line
automatically opens if the normal water-level sensor is not grounded by contact with water in the
cookpot. When sufficient water has been added to ground the low water-level sensor, the unit
automatically enters the SIMMER mode and remains there unless the operator presses the BOIL
mode switch or turns the unit off. When the water level in the cookpot reaches and grounds the
normal water-level sensor, the solenoid valve in the water supply line closes. Anytime the water
level in the cookpot drops below the normal water-level sensor, the solenoid valve opens to refill the
cookpot to the proper level.
While in the SIMMER mode, logic circuits in the controller monitor the temperature of the water
and cycle the burners on and off to maintain the temperature at the setpoint programmed into the
controller. (See Chapter 3 for instructions on adjusting the setpoint.) The cooker also has low-water
safety. If the water in the cookpot falls below the low water-level sensor, the controller cuts power
to the gas valve, causing it to close and cut off the gas supply to the burners.
The Autoskim feature (on units so equipped) is activated by pressing the Skim switch. When the
feature is activated, a logic circuit in the controller automatically opens the solenoid valve in the
1-1
water supply line for three seconds every minute until the option is turned OFF by again pressing the
Skim switch.
The operator enters a specified cooking time by pressing the number pads on the controller. When
the Start switch is pressed, the controller begins to count down to zero. When the controller times
out, an alarm sounds briefly, then the timer reverts to the last time entered.
When the START switch is pressed to start the cooking cycle, logic circuits in the controller activate
the basket lift motors (on units so equipped), lowering the basket into the cookpot. As the motors
drive the basket lift arms down, a cam attached to the left motor eventually loses contact with a
roller-activated microswitch and power to the motors is cut. When the controller times out, logic
circuits reverse the switch positions so that the motor circuit is again completed and the motors are
restarted, raising the basket from the cookpot. At the fully raised position, the cam again makes
contact with the microswitch, cutting power to the motors and stopping the lift in the up position.
THE ELECTRONIC IGNITION SYSTEM
The ignition module, located in the component box, is connected to ignitor assemblies at each
burner. The ignition module performs three important functions: it provides an ignition spark,
supplies operating voltage to the gas valve, and proofs the burner flame. NOTE: GSMS/GBC/GC
units manufactured before September 2000 have two single-spark ignition modules. Those
manufactured September 2000 and later have only one dual-spark ignition module.
The ignition module contains a 4-second time delay circuit and a coil that activates the gas valve.
The ignitor assembly consists of a spark plug, an enrichment tube, and flame sensor.
At start-up, the controller power switch is placed in the ON position, supplying approximately
12-volts DC to the heat control circuitry in the controller. If the controller senses the correct
operating parameters (i.e., the correct water level in the cookpot), it sends a signal to the 24VAC
relay in the component box to close the blower contacts. This supplies line voltage to the blower
motor. A centrifugal switch in the blower closes if the blower is operating correctly, which allows
24VAC to flow through the closed contacts of the 24VAC relay to the ignition module.
Circuitry in the ignition modules sends 24VAC to the gas valve. Simultaneously, the module causes
the ignitors to spark for 4 seconds to light the burners. A flame sensor for each burner verifies that
the burner is lit by measuring the flow of microamps through the flame. If the burner does not light
(or is extinguished), current to the ignition module is cut, preventing the gas valve from opening,
and the ignition module “locks out” until the controller power switch is turned off and then back on.
A probe monitors the temperature in the cookpot. When the programmed setpoint temperature is
reached, resistance in the probe causes the heat cycle circuitry in the controller to cut off current to
the 24VAC relay, thus cutting line voltage to the blower. This cuts the 24VAC to the ignition
module, causing the gas valve to close.
1.2 Accessing Equipment for Servicing
DANGER
Moving this equipment while it is filled with hot water may cause spilling or
splattering of the hot water. Always drain the cookpot before attempting to relocate
this equipment for servicing.
1-2
1. Disconnect the unit from the electrical power supply, the gas supply and the water supply.
2. Disconnect any attached restraining devices.
3. Relocate the unit for service accessibility.
4. After servicing is complete, reconnect the unit to the water supply and the gas supply. Reattach
the restraining devices, and reconnect the unit to the electrical power supply.
1.3 Replacing Equipment Components
1.3.1 Replacing the Controller
1. Open the control panel by removing the screws in the upper edge of the panel. Swing the panel
down and disconnect the 15-pin connector, trouble light wires, and ground wire. Remove the
control panel by lifting the panel out of the slots in the control panel frame.
2. Remove the failed controller from the control panel and replace with the new controller. Re-
verse Step 1 to complete the process.
1.3.2 Replacing Electronic Components Other than the Controller
1. Drain the cookpot and disconnect the cooker form the electrical power supply.
2. Remove the control panel in accordance with Step 1 of Section 1.3.1.
3. Remove the lower cover from the component box. Refer to the illustration below to locate the
component to be replaced.
(Present in GSMS and
GBC models only)
Cooker with Control Panel and
Component Box Cover removed.
NOTE: Wiring not show to provide a clearer view.
Basket Lift Relay
Transformer
Terminal Strip 24VAC Relay
Ignition Module
(There are 2 modules in units
built before September 2000.)
4. On the component to be replaced, make a note of the wiring connection points. Disconnect the
wires and remove the failed component. Install the replacement component and reconnect the
wiring in accordance with the notes made, or with the wiring diagram on the door of the unit.
1-3
5. Replace the component box cover, and reinstall the controller being sure to reconnect the ground
wire and trouble light wires. Reconnect the cooker to the electrical power supply.
1.3.3 Replacing a Water-Level Sensor or the Temperature Probe
1. Drain the cookpot and disconnect the cooker from the electrical power supply.
2. Remove the screws in the upper edge of the control panel and swing the panel down. Disconnect
the 15-pin connector, trouble light wires, and ground wire, and lift the panel out of the slots in
the control panel frame.
3. Remove the topcap from the unit by removing the four screws (two on the front and two on each
end) that secure it to the cabinet.
4. Remove the control panel frame by removing the screws in the top and bottom corners and, on
GSMS units, the screw in the center bracket.
5. If replacing a water-level sensor (see illustration below):
a. Disconnect the sensor lead by pulling it from its terminal then remove the Keps nut, terminal,
and washer from the sensor.
b. Inside the cookpot, remove the screw from the sensor flange.
c. Carefully pull the failed sensor from the probe block and replace with the new sensor.
d. Reassemble the washer, terminal, and Keps nut onto the sensor, and reattach the lead.
e. Reverse Steps 1-4 to complete the procedure.
If replacing the temperature probe, mark the wiring
harness leads and disconnect the probe leads at the
push on connectors.
Remove the s c r ews from the probe brac ket and
push the probe out t h e ba ck of the probe block.
Temperature Probe
Water-Level Sensors
If replacing a water-level sensor, disconnect its
lead and remove it s K e ps nut, termin al an d wash er .
Remove the s c r ew fr om the sensor f l an ge a nd
pull the sensor out the front of the probe block.
6. If replacing the temperature probe (see illustration above):
a. Mark the wiring harness leads and disconnect them from the probe leads at the push-on
connectors.
b. Remove the two screws in the probe bracket.
c. Carefully pull the probe from the probe clock and replace with the new probe.
d. Reattach the leads and reverse Steps 1-4 to complete the procedure.
1-4
1.3.4 Replacing the Pressure Regulator or Solenoid Valve
1. Drain the cookpot and disconnect the cooker from the electrical power supply. Turn off or
disconnect the water supply to the cooker.
2. Disconnect the solenoid leads at the push-on connectors. Disconnect solenoid and regulator
subassembly at the compression fittings on the water lines running to and from these
components. Remove the two screws in the mounting bracket and remove the solenoid and
regulator subassembly from the unit. (NOTE: If the cooker is not equipped with the optional
Autofill feature, the cookpot water tube will be connected directly to the regulator and there will
be no solenoid valve.)
The incoming water line will be connected
Remove the two screws
at the bottom of this
bracket to dismount the
solenoid and regul a t o r
sub-assembly.
Solenoid Valve
used, disconnect the regulator at this point.
to the nipple at th e i nlet side of the
regulator using some type of field
connection fitting. Whatever type fitting is
Solenoid Valve
Remove the two
screws at the
bottom of this
bracket to
dismount the
solenoid and
regulator sub-
assembly.
Disconnect the water
tubes at thes e
compression fittings.
GSMS with Autofill Configuration GBC/GC with Autofill Configuration
Disconnect t h e wat er tube
at this compression fitting.
3. If replacing the regulator, adjust the replacement regulator output pressure to not more than 40
PSI (28.15 kg/cm2) before installation in the cooker.
4. Recover the fittings from the failed component (regulator or solenoid valve) and install them on
the replacement, using thread sealer on all connections.
5. Reverse Steps 1 and 2 to complete the procedure, being sure to apply thread sealer to all
connections.
1.3.5 Replacing the Water Faucet
1. Drain the cookpot and disconnect the cooker from the electrical power supply.
NOTE: Refer to the illustration at the top of Page 1-6 for the following steps.
2. Turn off the water supply to the cooker and disconnect the incoming water lines where they
attach to the stubs at the rear of the cooker.
3. Remove the two screws securing the access panel in place and remove the panel.
4. Disconnect the water supply line at the compression fitting where it attaches to the water inlet
manifold. Remove the screws from the faucet mounting plate and lift the faucet assembly from
the unit.
1-5
Remove the six screws in
the faucet mounting plate.
Remove this nut to separate the
faucet from the mounting plate.
Disconnect wate r line at
this compression fitting.
Loosen this nut to separate the
faucet from the water inlet manifold.
5. Separate the faucet from the water inlet manifold and mounting plate as shown in the illustration
above.
6. Reverse Steps 1-5 to complete the procedure.
1.3.6 Replacing a Basket Lift Motor or Microswitch
1. Disconnect the cooker from the electrical power supply.
2. If rigid water connections have been used, disconnect the cooker from the incoming water
supply.
3. Remove the basket lift arms from the lifter rods and then reposition the cooker to gain access to
the rear. Remove the upper and lower basket lift rear panels.
4. Disconnect the basket lift synchronizer link from the lifter cam (bell crank) assemblies one at a
time. When the link is disconnected from a cam, slip the corresponding lifter rod down and out
of the assembly (see illustration on below).
Lifter Rods
Note the collection of washers and
spacers between the li nk and lifter rods.
Synchronizer Link
Lifter Cams
1-6
Disconnect the basket lift synchron izer
link from the lifter cams and slip the lifter
rods down and out of the ass embly.
5. Remove the four bolts securing the motor mount to the frame, then remove the motor and mount
assembly from the unit. NOTE: It is possible to replace a motor or the microswitch without
removing the motor and mount assembly, but it is much more difficult.
6. Dismount the motor or microswitch as shown below and install the replacement.
NOTE: The right motor dismount s
in the same way as the left.
Loosen setscrew in
bottom of cam (bell crank)
7. Reverse Steps 1-6 to complete the procedure.
1.3.7 Replacing Gas Supply System Components or Ignitor Assemblies
1. Disconnect the cooker from the electrical power supply and from the gas supply. If necessary,
disconnect restraints to gain proper access to components.
2. Disconnect the component to be replaced (see illustration below) and install the replacement
component. NOTE: If replacing the gas valve, disconnect the enrichment tubes and gas supply
tubes at the valve, then unscrew the valve from the mounting bracket. Recover the fittings from
the failed valve and install them on the replacement valve using a thread sealer suitable for gas
appliances (Loctite™ PST 56765 is one example). Do not apply the sealer to the first two
threads of the fitting. This will help prevent clogging of the burner orifices and gas valve.
Enrichment Tubes
Gas Supply Tubes
Ignitor Assembly
Ignitor Assembly Gasket
Gas Valve
Gas Valve Vent Tube
Gas Supply Tubes
connect to Burners here
When installing the Ignit or
Assembly, ensure the
spark plug is to the right.
1-7
3. Reconnect the cooker to the gas supply and check all connections for leaks using a solution of
soapy water.
DANGER
DO NOT use matches, candles, or other ignition methods to check for leaks.
4. When satisfied that there are no leaks, reconnect the unit to the electrical supply, and reconnect
any restraints disconnected in Step 1.
1.3.8 Replacing the Cookpot or Rinse Tank
NOTE: The following procedure addresses removing the cookpot or rinse tank from a GSMS unit.
The procedure is essentially the same for a GBC or GC unit, except that there is no faucet, and on
the GC unit, no basket lift.
1. Remove the basket lift arms from the lifter
rods.
Remove these four screws.
2. Remove the faucet assembly from the cooker
in accordance with Steps 1-4 of Section 1.3.5.
3. Remove the screws that secure each of the
rear corners of the backsplash assembly (see
illustration at right). NOTE: To access the
screw in the lower right corner (as viewed
from the rear) the upper basket lift back panel
must be removed.
Remove these
screws (on both
sides) and remove
backsplash and
topcap.
4. Remove the screws along the top edge of the
control panel and open the panel by swinging
it downward. Disconnect the 15-pin
connector from the rear of the controller and
the wires attached to the trouble light, and
then lift the control panel out of the control
panel frame.
5. Remove the screws that secure the backsplash
sides to the cabinet sides then remove the four
screws that secure the topcap to the cabinet.
6. Remove the top connecting strip.
Remove screws along the top edge of
control panel and dismount the panel.
Remove these screws to release
the pots from the standoff brack e ts.
Remove the top
connecting strip .
7. Remove the screws attaching the standoff
brackets to the cookpot or rinse tank.
8. If removing the cookpot, disconnect the
enrichment tubes and gas supply tubes from
the burner assemblies. Disconnect the
ignition cables and flame sensor wires from
the ignitor assemblies on each burner.
9. Lift the cookpot or rinse tank straight up and out of the cabinet.
1-8
10. Invert the cookpot or rinse tank on a suitable work surface and remove the salvageable
components (e.g., probe block assembly, blower assembly, drain plumbing, etc.). Install the
recovered components on the replacement cookpot or rinse tank, using thread sealer on all
connections.
11. Reverse Steps 1 through 9 to complete the procedure.
1.4 Troubleshooting
Problems with this equipment maybe grouped into five broad categories:
1. Failure or malfunction of a Power-Supply System component.
2. Failure or malfunction of the Controller.
3. Failure or malfunction of an Autofill/Autoskim System component.
4. Failure or malfunction of a Water Heating System component.
5. Failure or malfunction of a Basket Lift System component.
Sections 1.4.1 through 1.4.5 briefly explain the functioning of each of the systems mentioned above.
Section 1.4.6 contains troubleshooting guides that provide systematic procedures to isolate and
identify the specific source of a problem. A wiring diagram is located at the end of the chapter.
1.4.1 How the Power-Supply System Works
Line voltage is supplied to the system via a power cord that is plugged or hard-wired into the store’s
electrical service. The power cord is connected to pins 1 and 5 of an 8-pin terminal block. Line
voltage is supplied to a 24VAC transformer from pins 2 and 8 of the terminal block. Pin 7 supplies
24VAC to a heat relay, which controls line voltage to the blower motor and 24VAC to the gas valve
via the ignition module. The transformer supplies 24VAC to the controller, to the coils of the
24VAC relay, and to the solenoid valve on units equipped with the Autofill option. On units
equipped with basket lifts, line voltage is supplied to a 24VDC basket lift relay from pin 6 of the
power cord terminal block. Line voltage to the basket lift motors is supplied via the basket lift relay.
1.4.2 How the Controller Works
The SMS III controller provides the interface between the operator and the system components. The
controller is powered by 24VAC supplied through Pins 1 and 2 of the wiring harness. Internal circuitry senses the water level and water temperature. Depending upon the conditions sensed, the controller energizes or de-energizes the solenoid valve to control water level and the 24VAC relay to
control burner firing to control water temperature. The controller also controls the lowering and
raising of the basket lift, and activates an audible alarm to signal the operator that a cooking cycle
has completed. A rectifier in the controller converts 24VAC to the 24VDC required by the basket
lift relay. The controller signals for heat via Pin 4, grounds the solenoid valve via Pin 6, and senses
water level via Pins 7 (low) and 9 (full). The temperature probe connects to Pins 13 and 14. The
basket lift relay connects to Pins 10 and 12. The sound device connects to Pin 11.
1-9
1.4.3 How the Autofill/Autoskim System Works
The heart of the automatic filling (Autofill) system is a normally closed solenoid valve that opens
when 24VAC is applied.
The ground for the solenoid is supplied (via Pin 6 of the controller wiring harness) so long as the
shorter of the two water-level sensors is not in contact with the water in the cookpot. When the
water in the cookpot reaches the shorter of the two water-level sensors, the sensor is grounded. This
causes the controller to break the solenoid ground, closing the valve. Starch or lime build-up on the
sensor may keep it from grounding, therefore always make sure the sensor is clean and its lead (Pin
9 of the controller wiring harness) is firmly connected. Also, in order for the sensor to ground, there
must be some mineral content in the water (pure water is non-conductive). Consequently, the unit
will not operate correctly with distilled, highly filtered, or deionized water. If water of these types is
used, add ⅛-cup of baking soda to the water each time the cookpot is emptied and refilled. NOTE:
Do not use deliming solution to clean these units. Use of deliming solution will damage all stainless steel
parts.)
On units equipped with the Autoskim feature, a logic circuit in the controller automatically opens the
solenoid valve for three seconds every minute. If the Autofill feature is working properly, failure of
the Autoskim feature will be due to a malfunctioning controller and not the solenoid valve. (Proper
operation of the Autofill feature can be determined by draining water from the cookpot until the
water level is below the shorter of the two water-level sensors. If the solenoid valve opens and then
closes when the water in the cookpot again reaches the sensor, the Autofill feature is working
properly.)
1.4.4 How the Water Heating System Works
To prevent lighting the burners when there is no water in the cookpot, these units are equipped with
a low-water-level sensor (the longer of the two water-level sensors). This sensor must be grounded
by contact with water in the cookpot before the control circuitry will allow firing of the burners.
Starch or lime build-up on the low-water-level sensor may keep the sensor from grounding, therefore
always make sure the sensor is clean and its lead (Pin 7 of the controller wiring harness) is firmly
connected. Also, in order for the sensor to ground, there must be some mineral content in the water
(pure water is non-conductive). Consequently, the unit will not operate correctly with distilled,
highly filtered, or deionized water. If water of these types is used, add ⅛-cup of baking soda to the
water each time the cookpot is emptied and refilled. NOTE: Do not use deliming solution to clean
these units. Use of deliming solution will damage all stainless steel parts.)
In addition to the low-water-level sensor discussed above, the water heating system has three more
parts: the electronic ignition system, the temperature probe, and the controller.
The electronic ignition system controls firing of the burners. See Page 1-2 for a complete
description of this system.
The temperature probe is used only when the unit is in the simmer mode. When the simmer mode
is selected, logic circuits in the controller monitor the temperature of the water. When the water
temperature drops below the simmer setpoint, the controller closes the heat relay, causing the
burners to fire. When the water temperature reaches the setpoint, the controller opens the heat relay,
1-10
extinguishing the burners. This process repeats as required to maintain the temperature at the
setpoint programmed into the controller.
The controller is the interface between the operator and the other components of the equipment. In
the water heating system, its function is to control the firing of the burners.
1.4.5 How the Basket Lift System Works
When the Start switch is pressed to start the cooking cycle, logic circuits in the controller activate
the basket lift motors, lowering the basket into the cookpot. As the motors drive the basket lift arms
down, a cam attached to the left motor (when viewed from the rear) eventually loses contact with a
roller-activated microswitch and power to the motors is cut. When the controller times out, logic
circuits reverse the switch positions so that the motor circuit is again completed and the motors are
restarted, raising the basket from the cookpot. At the fully raised position, the cam again makes contact with the microswitch, cutting power to the motors and stopping the lift in the raised position.
1.4.6 Technician Troubleshooting Guides
PROBLEM PROBABLE CAUSES CORRECTIVE ACTION
A. Water not turned on. A. Turn on Water
Autofill does not add
water when water
level is below the
normal water-level
sensor (the shorter of
the two water-level
sensors).
B. Failed solenoid, failed computer,
or loose/broken wiring.
Test: Check for at least 22VAC at
Pin 5 of the 24VAC terminal block
and at solenoid end of wire 66C,
and check for ground (0 voltage) at
Pin 6 of 15-pin connector.
B. If voltage is present at solenoid
end of wire 66C, and Pin 6 of
15-pin connector is grounded (0
voltage present), check
continuity of wire 50C. If wire
50C is good, replace solenoid.
If voltage is present at solenoid
end of wire 66C and at Pin 6 of
15-pin connector, replace
controller.
If voltage is not present at
solenoid end of wire 66C, check
wiring between solenoid and
terminal block for loose
connection or break in the wire.
Autofill does not shut
off when the cookpot
is full.
A. Starch accumulation on the normal
water-level sensor (the shorter of
the two water-level sensors) is
preventing the sensor from
grounding.
B. Mineral content of water is too low
to provide a ground.
A. Clean the water-level sensors.
NOTE: Do not use deliming solu-
tion.
B. Add 1/8
th
cup of baking soda to
water in cookpot. DO NOT
USE SALT! Doing so will
damage the cookpot.
Continued on following page.
1-11
PROBLEM PROBABLE CAUSES CORRECTIVE ACTION
Continued from
previous page.
Autoskim does not add
water when selected
(Autofill feature
verified to be working
correctly).
Basket lift does not
lower when START
button is pressed or
rise when cooking
cycle completes.
Basket lift travels up
and down
continuously.
Basket lift travels
erratically or with
jerking motion.
Burner attempts to
light but will not
remain lit.
Burner will not light;
trouble light is on.
C. Failed solenoid, failed computer,
or broken/loose wiring.
Test 1: Check sensor-lead
connections on outside of cookpot
and at Pin 9 of 15-pin connector
and continuity of wire 71C.
Test 2: Check for AC voltage at
Pin 6 of 15-pin connector.
Test 3: Check for at least 22VAC
at solenoid end of wire 66C.
A. Failed controller. A. Replace controller.
A. Failed basket lift relay.
Test: Check for 13-17VDC at Pin
10 of 15-pin connector with basket
lift in the UP position, and for 0
volts with the basket lift in the
DOWN position.
B. Failed controller.
Test: Check for 13-17VDC at Pin
12 of 15-pin connector.
C. Failed or out of adjustment
microswitch.
Test: Check continuity of switch
and verify that roller contacts cam.
A. Bell crank slipping on shaft. A. Tighten bell crank setscrew.
B. Lift arms binding in bushings B. Lubricate lift arms.
C. Defective motor. C. Replace motor.
A. Flame sensor wire and ignitor ca-
bles crossed.
A. Cooker gas valve is turned off. A. Turn gas valve on.
B. Incoming gas line shut-off valve is
closed.
C. Action 1: Tighten connections
or replace wiring as required.
Action 2: If AC voltage is not
present, replace controller.
Action 3: If AC voltage is
present, replace solenoid.
If AC voltage is not present,
check wiring between solenoid
and terminal block for loose
connection or break in the wire.
A. If voltages are correct, replace
relay.
B. Replace controller if voltage is
below 12VDC.
A. Replace switch if it fails
continuity check.
Adjust switch mounting to
ensure roller contacts cam.
Ensure nut and locknut on shaft
are tight.
A. Verify that Sense 1 and Spark 1
connect to same ignitor.
B. Open incoming gas line shut-off
valve.
1-12
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