Lang Manufacturing GCCO-PP Parts List

Service Manual for the Lang Models:

GCCO-T, GCCO-AP, GCCO-SII, GCCO-C, GCCO-PP, GCCO-PT,

Lang Manufacturing Company 6500 Merrill Creek Parkway Everett, WA 98203
Phone: [phone] Fax: [phone]
www.langworld.com ©Copyright 2000

TABLE OF CONTENTS

CHAPTER

1. TABLE OF CONTENTS .......................................................................2

2. READ FIRST........................................................................................3

3. EQUIPMENT DESCRIPTION ..............................................................5

4. INSTALLATION.................................................................................... 7

5. START-UP ...........................................................................................10

6. CONTROL PANEL LAYOUT................................................................ 11

7. PROGRAMMING TERMS....................................................................17

8. PROGRAMMING .................................................................................18

9. GENERAL OPERATION ...................................................................... 28

10. TYPICAL OPERATION .......................................................................30

11. SEQUENCE OF OPERATION .............................................................33

PAGE

12. TROUBLESHOOTING .........................................................................37

13. TECHNICAL DATA ..............................................................................55

14. WIRING DIAGRAMS............................................................................ 61

15. PARTS LIST.........................................................................................67

2

IMPORTANT READ FIRST IMPORTANT

CAUTION

CAUTION

CAUTION

WARNING

NOTICE

NOTICE

WARNING

THE OVEN WEIGHS 500 LBS. FOR SAFE HANDLING, INSTALLER
SHOULD OBTAIN HELP AS NEEDED, OR EMPLOY APPROPRIATE
MATERIALS HANDLING EQUIPMENT (SUCH AS A FORKLIFT, DOLLY, OR
PALLET JACK) TO REMOVE THE UNIT FROM THE SKID AND MOVE IT TO
THE PLACE OF INSTALLATION.

ANY STAND, COUNTER OR OTHER DEVICE ON WHICH THE OVEN WILL
BE LOCATED MUST BE DESIGNED TO SUPPORT THE WEIGHT OF THE
OVEN.

SHIPPING STRAPS ARE UNDER TENSION AND CAN SNAP BACK WHEN
CUT.

INSTALLATION OF THE UNIT MUST BE DONE BY PERSONNEL QUALIFIED
TO WORK WITH PLUMBING. IMPROPER INSTALLATION CAN CAUSE
INJURY TO PERSONNEL AND/OR DAMAGE TO EQUIPMENT. UNIT MUST
BE INSTALLED IN ACCORDANCE WITH ALL APPLICABLE CODES.

The data plate is located above control panel behind wire mesh screen.
The oven serial number, gas specifications, and clearance specifications
are on the data plate. This information should be carefully read and
understood before proceeding with the installation.

The installation of any components such as a vent hood, grease
extractors, fire extinguisher systems, must conform to their applicable
National, State and locally recognized installation standards.

THIS APPLIANCE IS EQUIPPED WITH A 3-PRONG (GROUNDING) PLUG
FOR YOUR PROTECTION AGAINST SHOCK HAZARD AND MUST BE
PLUGGED DIRECTLY INTO A PROPERLY GROUNDED 3-PRONG
RECEPTACLE. DO NOT CUT OR REMOVE THIS GROUNDING PRONG
FROM THE PLUG.

WARNING

NOTICE

WARNING

NOTICE

CAUTION

CONVECTION OVENS INSTALLED WITH CASTERS MUST HAVE THE
FOLLOWING: A CONNECTOR THAT COMPLIES WITH THE STANDARD
FOR CONNECTORS FOR MOVABLE GAS APPLIANCES ANSI Z21.69
LATEST EDITION, A QUICK DISCONNECT THAT COMPLIES WITH THE
STANDARD FOR QUICK DISCONNECT DEVICES FOR USE WITH GAS
FUEL, ANSI Z21.141 LATEST EDITION, A TETHER OR OTHER MEANS TO
LIMIT APPLIANCE MOVEMENT WITH OUT RELIANCE ON THE GAS
SUPPLY PIPING. SECURELY ATTACH THE TETHER TO THE EYEBOLT
PROVIDED AT THE REAR OF THE APPLIANCE.

Kits designed to accommodate ovens from sea level to 5000 feet. Contact
factory for orifice sizes on installations above 5000 feet.

BEFORE LIGHTING, USE A SOAP AND WATER SOLUTION TO TEST ALL
JOINTS FOR GAS LEAKS.

During the first few hours of operation you may notice a small amount of
smoke coming off the oven, and a faint odor from the smoke. This is
normal for a new oven and will disappear after the first few hours of use.

ALWAYS KEEP THE AREA NEAR THE APPLIANCE FREE FROM
COMBUSTIBLE MATERIALS.

3

IMPORTANT READ FIRST IMPORTANT

CAUTION

WARNING

CAUTION

NOTICE

NOTICE

WARNING

CAUTION

KEEP FLOOR IN FRONT OF EQUIPMENT CLEAN AND DRY. IF SPILLS
OCCUR, CLEAN IMMEDIATELY, TO AVOID THE DANGER OF SLIPS OR
FALLS.

KEEP WATER AND SOLUTIONS OUT OF CONTROLS. NEVER SPRAY OR
HOSE CONTROL CONSOLE.

MOST CLEANERS ARE HARMFUL TO THE SKIN, EYES, MUCOUS
MEMBRANES AND CLOTHING. PRECAUTIONS SHOULD BE TAKEN TO
WEAR RUBBER GLOVES, GOGGLES OR FACE SHIELD AND PROTECTIVE
CLOTHING. CAREFULLY READ THE WARNING AND FOLLOW THE
DIRECTIONS ON THE LABEL OF THE CLEANER TO BE USED.

Never leave a chlorine sanitizer in contact with stainless steel surfaces
longer than 10 minutes. Longer contact can cause corrosion.

Service on this, or any other, LANG appliance must be performed by
qualified personnel only. Consult your authorized service station directory
or call the factory at 1-800-224-LANG (5264), or WWW.LANGWORLD.COM
For the service station nearest you.

BOTH HIGH AND LOW VOLTAGES ARE PRESENT INSIDE THIS
APPLIANCE WHEN THE UNIT IS PLUGGED/WIRED INTO A LIVE
RECEPTACLE. BEFORE REPLACING ANY PARTS, DISCONNECT THE
UNIT FROM THE ELECTRIC POWER SUPPLY.

USE OF ANY REPLACEMENT PARTS OTHER THAN THOSE SUPPLIED BY
LANG OR THEIR AUTHORIZED DISTRIBUTORS CAN CAUSE BODILY
INJURY TO THE OPERATOR AND DAMAGE TO THE EQUIPMENT AND
WILL VOID ALL WARRANTIES.

4

EQUIPMENT DESCRIPTION

Lang Model: GCCO

GAS FULL SIZE CONVENTION OVEN

EXTERIOR

• The oven exterior dimensions are 40” (100 cm) Wide, 32” (80 cm) High, 38” (95
cm) Deep. The Top, Front, Back, and Sides are constructed of stainless steel with an
aluminized bottom.

• The oven doors come standard with a double pane window.

• The door handle is constructed of Stainless Steel and Phonolic Tubing.

• The oven cavity is insulated with high temperature insulation for efficiency and

reduced heat loss.

INTERIOR

• The oven cavity dimensions are 29” (72.5 cm) Wide, 20” (50.84 cm) High, 21”
(53.38 cm) Deep.

• The oven is designed for five shelves and comes with five Chrome Plated Racks.

• The interior of the oven is constructed of porcelainized stainless steel.

OPERATION

• The GCCO oven is a forced air convection oven with a vented oven cavity.

• The air is driven by a 1/3 HP fan motor.

CONTROLS

The GCCO is available either with the Lang Accu-Temp (GCCO-T), Accu-Plus (GCCO­AP), Selectronic (GCCO-SII), “Purple” Computer (GCCO-C), “Purple Plus” Computer
(GCCO-PP), “Platinum” Computer (GCCO-PT):

• GCCO-T

 Easy to use manual control knobs.
 Pulse and two speed fan.

• GCCO-AP

 Easy to use manual control knobs.
 Pulse and two speed fan.
 Solid State temperature sensing and controls.

• GCCO-C

 Complete Computerized Controls with a Manual Override system.
 Programmable up to 10 products with four “tiers” for each program.
 Independent Shelf Timers for each Shelf.
 Load Control through use of Cooking Curves.
 Shelf Compensation Timing for uniform baking.
 Single speed fan.

• GCCO-PP

 The Purple Plus offer the same great one touch system of the Purple, coupled

with the advanced backing capabilities of the new Platinum.

5

• GCCO-PT

 Icon-driven (touch) panel allows for easy operation, also includes a manual

override system.

 Day-Part Memory capabilities allow operators to “recall” the last daily

selections automatically.

 Programmable up to 99 products, advanced baking capabilities include: a

12:59:59 timer with ten “tiers” .

 Independent Shelf Timer for each Shelf.
 Load Control through use of Cooking Curves.
 Shelf Compensation Timing for uniform baking.
 Dual speed fan.

EQUIPMENT DESCRIPTION CONT’D

6

RECEIVING THE OVEN

Upon receipt, check for freight damage, both visible and concealed. Visible damage should
be noted on the freight bill at the time of delivery and signed by the carrier's agent.
Concealed loss or damage means loss or damage, which does not become apparent until the
merchandise has been unpacked.
If concealed loss or damage is discovered upon unpacking, make a written request for
inspection by the carrier's agent within 15 days of delivery. All packing material should be
kept for inspection.
Do not return damaged merchandise to Lang Manufacturing Company. File your claim
with the carrier.
Prior to un-crating, move the oven as near its intended location as practical. The crating
will help protect the unit from the physical damage normally associated with moving it
through hallways and doorways.

LEG INSTALLATION

Legs are available for both the single and double deck installations. Single deck
installations require a 27-inch leg. Double deck installations require 6-inch legs or casters.
To install the 27-inch legs, place some cardboard on the floor and gently tip the oven onto
its back. Fasten two legs to the oven's front corners using the four 5/16 inch bolts provided
in the leg kit. Lift the oven onto its front legs and block the back up using one of the 27­inch legs set upside down in the center rear of the oven body. Install the last 27-inch leg
onto the oven body on the control side rear. Gently lift the oven rear, remove the leg set to
support the oven center and install it on the last rear corner.
To install the 6-inch legs or casters, attach the leg or caster to the leg supports supplied in
the oven by following the instructions in the box, then attach the leg support to the oven.
The adjustable feet on the bottom of each leg may be screwed in or out as necessary to level
the oven.
A torpedo level placed on an oven rack will assist in leveling the oven.

INSTALLATION

STACKING THE OVENS

Remove all the plug buttons from the top of the lower oven.
Remove the stacking kit from the oven compartment of one oven and install the 1 1/4-inch
plastic bushing into the top of the lower oven.
Tip the top oven backwards and install two 3/8-inch socket head bolts, found in the stacking
kit, into the two front leg holes that match the holes in the top of the lower oven. Install the
socket head bolts with the heads of the bolt pointing away from the oven.
Lift the top oven and gently set on top of the lower oven so that the heads of the socket
head bolts nest into the holes in the top of the lower oven.

ELECTRICAL CONNECTION

The electrical connection must be made in accordance with local codes or in the absence of
local codes with NFPA No. 70 latest edition (in Canada use: CAS STD. C22.1).
The electrical service entrance is provided by a cord and plug located at the oven back
directly behind the control compartment.
Each oven requires a 115-volt grounded supply and 7.1 amps.
Supply wire size must be large enough to carry the amperage load for the number of ovens
being installed. Wire size information can be found on the oven data plate.

7

INSTALLATION CONT’D

GAS CONNECTION

This appliance is manufactured for use with the type of gas indicated on the data plate.
Contact the factory if the gas type does not match that which is on the data plate.
All gas connections must be in accordance with local codes and comply with the National
Fuel Gas Code ANSI Z223.1 latest edition.
An internal gas pressure regulator is located inside the control compartment.
Gas must be delivered to the appliance regulator at less than 1/2 pound of pressure and less
than 1/2-inch water column pressure drop.
The internal regulator is preset at the factory, however, due to gas pressure variations from
area to area, adjust the regulator to provide the manifold pressure indicated on the data
plate. This should be 5 inches water column for natural gas and 10 inch water column for
propane. A 1/8-inch NPT tap is provided on the main manifold for checking regulator
pressure. Access the main manifold by removing the trim piece below the oven doors.
When replacing the 1/8-inch plug in the main manifold a joint sealant that is resistant to the
action of liquid petroleum gas must be used.
The supply piping must be of sufficient size to provide 55,000 BTU/hr per oven. A 1/2­inch NPT connection is provided at the rear of the oven directly behind the control
compartment. Connect each oven separately.
A gas shut off valve must be installed to the oven(s) and located in an accessible area.
This appliance and its individual shutoff valve must be disconnected from the gas supply
piping system during any pressure testing of that system at test pressures in excess of 1/2
PSGI (3.45 kPA) and the appliance must be isolated from the gas supply piping system by
closing its individual manual shutoff valve during any pressure testing of the gas supply
system at test pressures equal to or less than 1/2 PSIG (3.45 kPA).
Test for gas leaks. Use a commercial leak detector or a soap and water solution.

FLU EXTENSION

 A flu extension must be installed on the lower oven of a stacked set.
 The extension attaches to the flu opening of the lower oven and directs the flu products

into the flu opening of the upper oven.

 This extension must be installed.
 The ovens may now be set into position. Be careful if sliding the ovens, they are not

designed to slide over cracks or obstructions in the floor.

8

Gas Conversions

1. Disconnect oven from power and gas.

2. Remove bottom trim piece from oven (2 hex head bolts and 1 Phillips screw).

3. Remove side panel from oven.

4. Disconnect black manifold pipe from 3/8” aluminum pipe at the furrel nut.

5. Remove two Phillips screws holding black manifold pipe to oven.

6. Remove black manifold pipe from oven.

7. Remove both burner orifices from manifold and replace with new orifices, making
sure to apply pipe thread compound.

8. Remove two Phillips screws holding pilot assembly to oven.

9. Remove pilot assembly from oven.

10. Remove ¼” aluminum pipe from pilot assembly.

11. Remove pilot orifice and replace with new pilot orifice.

12. Re-attach ¼” aluminum pipe to pilot assembly.

13. Re-attach pilot assembly to oven.

14. Re-install black manifold assembly to oven, making sure that the orifice goes into
the burner tubes.

15. Re-attach 3/8” aluminum pipe to black manifold assembly.

16. Remove the seal screw from the combination gas valve.

17. Remove the adjustment screw and spring from the combination valve.

18. Insert new spring into the valve and adjustment screw.

19. Re-connect oven to power and gas and check for leaks using a soap solution.

20. Adjust gas pressure to correct water column (5”NG, 10”LP).

21. Install new seal screw provided in kit and affix “Caution” sticker to the visible side
of the combination valve.

22. Re-install bottom trim piece and side panel.

INSTALLATION CONT’D

NG to LP LP to NG

Part No. Description Qty. Part No. Description Qty.
80401-05 Pilot Orifice, Drilled .010 1 80401-10 Pilot Orifice, Drilled .018 1
80400-14 Main Burner Orifice, Drilled #53 2 80400-13 Main Burner Orifice, Drilled #43 2

80505-11

Combination Gas Valve Spring,
Includes:

1. Spring

2. Seal Screw

3. Caution Sticker

1

9

80505-16

Combination Gas Valve Spring,
Includes:

1. Spring

2. Seal Screw

3. Caution Sticker

1

GCCO-AP / GCCO-C / GCCO-PP / GCCO-PT / GCCO-SII / GCCO-T

Convection Oven Start-Up

1) Verify connections at plug and terminal block

2) Incoming Gas - Water Column________

Natural Gas Propane

3) Incoming Voltage L1______

4) Motor amp draw ______

5) Are programs correct? Yes No

6) Verify actual temperature at 350 °F ________ °F.
Note:
Install thermocouple wire in center of oven cavity.
Let oven cycle off and on 3 times before recording temperature.

START-UPS

Set manual program in the computer for 350 °F

Model #_______ Date_______ Serial #________

Store #___________ Tech Name___________________
Contact_______________ Company _________________________
Store Phone #___________ Service Company Phone #______________

Address_____________________
______________________
______________________

10

CONTROL PANEL GCCO-T

Vent Knob.

ON

Power switch.

OFF

Pulse fan switch. Pulse fan
setting will only turn the fan
on when the oven is calling

Temperature Control. Allows
temperature to be set from
100°F - 450°F in 50°F.

LIGHT

PULSE FAN HI-SPEED

FAN

LOW-SPEED

TEMP

TIME

Light switch. Inspection light
only. Push toggle switch to the
up position to inspect product.
Switch will automatically return to
the off position.

Dual speed switch.
Toggles the fan between
high and low speed.

Timer Control. Electronic one
hour timer with continuous
beeper.

11

CONTROL PANEL GCCO-AP

Vent Knob.

ON

Power switch.

OFF

Pulse fan switch. Pulse fan
setting will only turn the fan
on when the oven is calling

Temperature Control. Allows
temperature to be set in 25°F
increments from 140°F.

LIGHT

PULSE FAN HI-SPEED

FAN

LOW-SPEED

TEMP

TIME

Light switch. Inspection light
only. Push toggle switch to the
up position to inspect product.
Switch will automatically return
to the off position.

Dual speed switch.
Toggles the fan between
high and low speed.

12

Timer Control. Electronic one
hour timer with continuous
beeper.

CONTROL PANEL GCCO-SII

p

Vent Knob.

Light switch. Inspection light only.
Push toggle switch to the up
position to inspect product. Switch
will automatically return to the off
position.

Pulse fan switch. Pulse fan
setting will only turn the fan
on when the oven is calling

LED Display.

ON

OFF

LIGHT

PULSE FAN HI-SPEED

FAN

TEMP/TIME

COOK N HOLD

LOW-SPEED

8 8 8

Power switch.

Cook N Hold switch.
Oven will automatically
drop to 140°F when oven
timer stops timing down.

Dual speed switch.
Toggles the fan between
high and low speed.

Adjustment Arrows.
Adjusts the LED display
for time and temp.

TEMP TIMER

Temp Button. Press
to set desired temp.

13

START

STOP

BUZZER

Start/Stop Button. Starts
and sto

Timer Button. Press to
set desired time.

s the timer.

Power Switch

LED Display

CONTROL PANEL LAYOUT GCCO-C

Light switch

Tier Indicator: Displays what Tier
(cycle) of a certain program is
running.

Product Button: Used to
program and store product
into the computer.

Manual Program Button:
Used to input a one time
only program.

Shelf Button: Used to tell the
oven which shelf the product
is on.

Read/Clear Button: Used as a
programming key.

Temperature Button: Press at any
time to display oven temperature.

14

CONTROL PANEL LAYOUT GCCO-PP

Light switch. Inspection light only.
Push toggle switch to the up
position to inspect product. Switch
will automatically return to the off
position.

AlphaNumeric Display.

Product Select Button.
Press to select desired
product.

LIGHTS

On

Off

POWER

On

Power switch.

Off

Shelf Select Button. Press
to select shelf which

1

2

6A

7

B

product will be placed.

Manual Program Button.
Use when product being
cooked is for one time only.

3

4

5

Man

Prog

15

8

C

9

D

0

E

Read/Clear Button. Used

Read
Clear

to read programs, clear
programs, and to access
program menu.

A

p

y

Function keys. Keys are
active when a program
option is displayed on
display.

CONTROL PANEL LAYOUT GCCO-PT

Alpha-Numeric Display.

Cancel button. When
scrolling through menu’s
this will allow you to back
up to the previous menu.
In program mode this will
allow you to advance to the
next ste

Arrow up button. Allows

ou to scroll up.

.

X

Cancel

Up Down Light

P L A T I M U M

Light switch. Inspection light only.
Push for light to come on. Light will
automatically turn off.

Power switch.

On/Off

rrow down button. Allows

you to scroll down.

16

Control Panel Buttons

PROGRAMMING TERMS

1 -0

A - E

MAN PROG

READ/CLEAR

 It is always the first button pressed when entering programming codes.
 Pressing it twice then pressing a Product Button will "read-back" the program

 Pressing and holding the button down until "88888" appears in the display will

Temp

Programming Terms

Cooking Curve

Product Buttons. These are the buttons where the product programs are stored.
Pressing a Product Button will heat the oven to the programmed temperature.

Shelf Buttons. The control is capable of timing each shelf individually. Pressing a
Product Button then a Shelf Button will start the countdown timer.

The MANUAL PROGRAM button allows the operator to enter a temporary
product program without being required to input the programming code. The
temporary program is erased when the oven is turned off or when a new program is
entered. Time and temperature are the only parameters that can be entered in the
Manual Program mode.

The READ/CLEAR button has several functions.

in that product button.

cancel the current mode of the control and return the display to "Enter".

When the Temperature Recall Button is pressed, the display will indicate the
internal oven temperature. When released the display will revert to the previous
readout.

Cooking curve is a function of the computer that controls the cooking time. If the
temperature of the oven is lower than the programmed temperature, the control will
slow the timer down to compensate for the lower cooking temperature. Cooking
Curves from 0 - no time adjustment to 7 - maximum adjustment are available.
Cooking Curve 3 is the most commonly used. However, as a general rule the
longer the cooking time the lower the cooking curve, the shorter the cooking time
the higher the cooking curve.

FAN FUNCTION

TIER

The convection fan has two programmable options. Fan On (Fan 1) runs the
convection fan continuously. Fan Off (Fan 0) leaves the fan off until heat is called
for by the control. In a convection oven, the fan must
comes On. The convection fan can not

"Tiered" programming is the ability to change the cooking temperature or fan
function during the cooking cycle. As an example, some products require the fan
to be Off for the first half of the cooking cycle then turn On for the last half, Tier 1
would be programmed with the fan in the Off mode then Tier 2 would be fan On.
The Tier lamps located below the display (labeled T1, T2, T3, and T4) will
illuminate to indicate which Tier is being programmed or which Tier the program
is in during the cooking cycle.

be turned Off continuously.

17

come On whenever the heat

PROGRAMMING

ACTION DISPLAY

Turn the power switch on. If the oven is already on,
turn it off and then back on.

PROGRAMMING GCCO-C

enter

Quickly enter access code “R/C 1 6 2 7 3 8”. Do
not hold the R/C button.

Select a Product number from 0-9.

Select amount of time that product should steam. If
no steam is required press the shelf “A” button to
advance to the next step.

Note: If oven is not strapped for steam convection

then this step will not be provided.

Select a Temperature from 150°F-450°F.
NOTE: Entering “000” will erase the existing
program.

Select the desired cooking curve from 0-7.

Enter a desired Fan setting.

“0” (nofan) Will make the fan pulse with the heat.

“1” (fanonhi) Will make the fan run on high

continuously.

“2” (fanonlo) Will make the fan run on low

continuously.

Enter the desired cooking time
(hours:minutes:seconds)

prod

St: 00

000°F

CC0-7

Fano12

00: 00: 00

000°f

The program is now entered for a single tier
program, press the “E” button to continue
programming other products. If the program is a
multi tiered program continue by programming the
next tiers. When complete press the “E” button.

When the programs have been completely entered
press the “R/C” button to save and exit the
programming cycle.

18

prod

enter

PROGRAMMING GCCO-C CONT’D

GCCO-C STATUS DISPLAY

The Status Display informs the operator of the oven's status.

It can be used as a countdown timer, shelf in use or internal oven temperature display during the
cooking cycle (see GCCO-C Programming Codes).

The Display informs the operator when the oven is ready to bake, or if the oven is above or below the
programmed temperature.

Below is a list of displays and their definitions:

"

ENTER" The oven is energized and ready for an operator command.

"

PrEht" Stands for “PREHEAT”. A product has been selected and the oven is

heating to the programmed temperature.

"

rEAdY” A product has been selected and the oven has preheated to the

programmed temperature. The oven is ready to load a product.

"

COOL" The oven's internal temperature is below what is programmed.

"

Hot" The oven's internal temperature is above what is programmed.

"

ShELF" A product selection has been made after the oven has preheated and the

computer is asking which shelf the product is placed on.

"

hELP" There is a fault in the control system, the computer will not operate until

service is performed.

"

Cont" Stands for “CONTINUOUS”. The oven has been programmed without a

time being entered. The oven will operate continuously at the
programmed temperature.

"

ErrOr" An entry has been made during the programming, which the computer

does not understand.

19

PROGRAMMING GCCO-C CONT’D

GCCO-C PROGRAMMING CODES

Below are codes, which will allow you to configure the display or aid in the operation, and
troubleshooting of the oven.
The readout must display "ENTER" before the computer will accept any programming code. If the
readout displays any other word, reset the computer by pressing and holding the “R/C” button until
display reads “88888” then release. Display should now read “ENTER”.
The control allows for a 3-second delay between each button push, if a delay of longer than 3 seconds
has occurred, the programming code must be re-entered.
The instructions call for pressing exactly what is shown under "PRESS".

CODE DESCRIPTION PRESS

• OPERATIONAL

Recall time remaining on a shelf Shelf

Cancel a shelf timer R/C, R/C, Shelf

• DISPLAY MODES

Countdown timer display R/C,4,8,4,8,4,8

Shelf in use display R/C,0,9,0,9,0,9

Internal oven temperature display R/C,8,7,8,7,8,7

• PROGRAMMING

Enter programming mode R/C,1,6,2,7,3,8

Recall an existing product program R/C, R/C, P (Product programmed)

Erase a product program R/C,1,6,2,7,3,8 (P) (000)

Model identification R/C, D,C,D,C,D,C

Fan Setting ( HI or Both) R/C,E,D,C,B,A,1(high),2 (both)

Program download (Contact Factory) R/C, A, B, C, D, E, P

• MAINTENANCE

Actual oven temperature

Return to ENTER

R/C,3,4,5,6,7,8

R/C

• SHELF COMPENSATION

Enter shelf compensation mode R/C, C, B, C, B, C, B

Set shelf compensations (I.E.) A,2,3,A

Return to ENTER R/C

20

ACTION DISPLAY

Turn the power switch on. If the oven is already on,
press the Read / Clear key until the following screen
is displayed.

Enter access code “1 6 2 7 3 8”.

Select “C”.

Select a number from 0-9 and press the key

corresponding to that number.

If a product Key selected already has a program, the
screen will read.

Enter a desired cooking / baking temperature. The
screen will automatically advance to the next
display.

Enter the cooking time and then press “E” to
advance to the next screen.

Enter the desired cooking curve. (Refer to sections

6.3 and 6.7 for more detail)

Select Fan speed. (Hi=1700 rpm, Low=1400)

Select Fan Pulse rate. (0 to 100%). 0=off unless
calling for heat. 100=on at all time.

NOTE:

fan will be on that many number of seconds in a
100-second block. (E.g. 67%= on for 67 seconds in
a 100 second block)
If your press 1 you will go through the same
sequence as outlined above. If you press 2 the next
display will automatically appear.

Any number between 0-100 means that the

PROGRAMMING GCCO-PP

SELECT PRODUCT OR

READ/CLEAR TO

PROGRAM

XX:XXPM XXXF

A: SET TIME
B: SET DATE
C: PROGRAM PRODUCTS
D: NEXT MENU

PRODUCT PROGRAM MODE

SELECT PRODUCT

NUMBER 1-9

EDIT PRODUCT?

1=EDIT OR 2=DELETE

NXX TX XXXF CX

XX:XX:XX PXXX F-XX

ENTER COOKING TEMP

100 TO 450 F

NOX T1 XXXF

ENTER COOKING TIME

HR:MIN:SEC

NOX T1 XXXF CO

ENTER COOKING CURVE

0 TO 100%
NOX T1 XXXF CXX
XX:XX:XX PXXX F-XX

ENTER FAN SPEED

1=HI 2=LOW
NOX T1 XXXF CXX
XX:XX:XX PXXX F-XX

ENTER FAN PULSE RATE

1 TO 100%

NOX T1 XXXF CXX

XX:XX:XX PXX F-XX

CONTINUE TO TIER 2

1=YES 2=NO
NOX T1 XXXF CXX
XX:XX:XX PXXX F-XX

A: SET TIME
B: SET DATE
C: PROGRAM PRODUCTS
D: NEXT MENU

21

PROGRAMMING GCCO-PT

ACTION DISPLAY

Step 1. Turn the power switch on. If the oven is

already on, press the “CANCEL” key until
the following screen is displayed.

Step 2. Select:

 TIME / DATE / PROGRAM.

 RUN OVEN

 TIME / DATE / PROGRAM

TIME DATE TEMP STATUS

12:00 01/01/01 325 STANDBY

ACTION DISPLAY

 DISPLAY PRODUCT

 TIMER ONLY

Step 3. Select :

 SET TIME / DATE

 PROGRAM COMPUTER

 PROGRAM COMPUTER

TIME DATE TEMP STATUS

12:00 01/01/01 325 PROGRAM

ACTION DISPLAY

Step 4. Using the  and  arrows, enter access

code “A B C D E F”

Press  or  to scroll through letters and numbers,
then select “ENTER” to move the cursor to the right.

EXAMPLE: Press  once for an “A”, then press

“ENTER”. Press  twice for a “B”, then
select “ENTER”. Continue through “F”.
The screen will then automatically
advance once access code has been
entered correctly.

 ENTER

PRESS CANCEL TO QUIT

22

ENTER ACCESS CODE

A

USE  KEYS TO SELECT

THEN PRESS ENTER

PROGRAMMING GCCO-PT CONT’D

ACTION DISPLAY

Step 5. Select:

 PROGRAM PRODUCTS

ACTION DISPLAY

Step 6. Select:

 CREATE NEW PRODUCT

 PROGRAM PRODUCTS

 EDIT READY ZONE

 EDIT ACCESS CODE

 ENABLE MANUAL PRODUCT

 CONFIGURE TIME OF DAY

 CREATE NEW PRODUCT

 EDIT PRODUCT

 DELETE PRODUCT

 EDIT PRODUCT

ACTION DISPLAY

Step 7. “SELECT PRODUCT ICON” is the first

screen when creating a product program.
Press  until you find an icon that best
resembles your product. If necessary, press
 to go backward through the icon list.
Select “ENTER” to accept the icon, and more
to the next screen

SELECT PRODUCT ICON

USE  KEYS TO SELECT

THEN PRESS ENTER TO ACCEPT

APPETIZER A

 ENTER

23

PROGRAMMING GCCO-PT CONT’D

ACTION DISPLAY

Step 8. “SELECT PRODUCT NAME” is where you

spell the name using the  or  to select
each letter. Then select “ENTER” to move
the cursor to the next space and select a new
letter.

NOTE: “A
replaced with the new product name or blanks, when
the product name is shorter than “A

EXAMPLE: “APPLE” replaces only APPET

Step 9. “SELECT PRODUCT TEMPERATURE”

EXAMPLE: (320) Press

PPETIZER A” is the name that must be

PPETIZER A”.

, IZER A
must be replace by blanks. A blank can
be found before “A” or after “9” when
scrolling.

ACTION DISPLAY

Press the  or  to select a number. Then
select “ENTER” to move the cursor to the
next space and select a new number. The
screen will automatically advance after you
enter the last number.



three times for a “3”, then
select “ENTER” to advance the cursor.
Press



two times for a “2”, then select
“ENTER” to advance the cursor. Since
“0” is already displayed just select
“ENTER” to advance to the next screen.

 ACCEPT
 ENTER

TIER 1

 ACCEPT
 ENTER

ACTION DISPLAY

Step 10. “SELECT TIER COOK TIME”. Time is

entered in hours:minutes:seconds. The
maximum is 12:59:59. Select “ENTER” to
advance cursor to the place you want to
enter a number.

EXAMPLE: (45 minutes:00 seconds) Select “ENTER”

twice to advance from hours to minutes,
then press
select “ENTER” to advance the cursor.
Then press
select “ENTER” to advance the cursor.
Since “0” is the next two numbers simply
select “ENTER” again twice to advance
the cursor.



four times for a “4”, then



five times for a “5”, then

 ACCEPT
 ENTER

SELECT PRODUCT NAME

A

PPETIZER A

USE  KEYS TO SELECT

APPETIZER A

SELECT PRODUCT TEMPERATURE

100

USE  KEYS TO SELECT

APPLE

SELECT TIER COOK TIME

00:45:00

USE  KEYS TO SELECT

APPLE

TIER 1
TEMP: 320F

24

PROGRAMMING GCCO-PT CONT’D

ACTION DISPLAY

Step 11. “SELECT COOKING CURVE”. Press  or

 to select numbers, select “ENTER” to

move the cursor to the next space. Cooking
curve may be any number between 0% and
100%.

EXAMPLE: (80

the cursor one space, then press
times for a “8”. Select “ENTER to
advance the cursor. Since “0” is the next
number, select “ENTER” to advance to
the next screen.

%

) Select “ENTER” once to advance



eight

 ACCEPT
 ENTER

ACTION DISPLAY

Step 12. “SELECT FAN SPEED”. The cursor will

HIGH

automatically appear under HIGH
your default setting. Press “ENTER or
ACCEPT” to keep high fan and advance to
the next screen. If LOW
setting press the  or  to move the cursor
to low. Once low is selected, select “ENTER
or ACCEPT” to move to the next screen.

is the correct

, that is

LOW

COOKING CURVE:

 ACCEPT
 ENTER

SELECT COOKING CURVE

000 %

USE  KEYS TO SELECT

APPLE

TIER 1
TEMP: 320F TIME: 00:45:00

SELECT FAN SPEED

USE  KEYS TO SELECT

APPLE

TIER 1
TEMP: 320F TIME: 00:45:00

80 %

25

PROGRAMMING GCCO-PT CONT’D

ACTION DISPLAY

Step 13. “SELECT PULSE RATE”. Press  or  to

select numbers, select “ENTER” to move the
cursor to the next space. 100% is the
default. If this okay, select “ENTER” three
times or “ACCEPT” once to advance to the
next screen.

EXAMPLE: (80

“ENTER” once to advance the cursor one
space, then press
Select “ENTER to advance the cursor.
Since “0” is the next number, select
“ENTER” to advance to the next screen.

%

) Press the  once for “0”. Select



eight times for a “8”.

TIER 1
TEMP: 320F TIME: 00:45:00

FAN: HI

COOKING CURVE:

 ACCEPT
 ENTER

ACTION DISPLAY

Step 14. “CORRECT”. The cursor automatically

YES

appears on “YES”. The computer is asking
if the program displayed is correct. If any
part of that program is incorrect, press  or
 till the cursor is on “NO
or “ACCEPT”. This will return you to step 7.
Selecting “YES
sceen.“NO”.

” will advance the

”. Select “ENTER”

NO

TIER 1
TEMP: 320F TIME: 00:45:00

FAN: HI RATE:

COOKING CURVE:

 ACCEPT
 ENTER

SELECT PULE RATE

1

00 %

USE  KEYS TO SELECT

APPLE

USE  KEYS TO SELECT

APPLE

80 %

CORRECT?

80 %

100 %

26

PROGRAMMING GCCO-PT CONT’D

ACTION DISPLAY

Step 15. “CONTINUE TO NEXT TIER”. The cursor

automatically appears on “NO
“ENTER” or “ACCEPT” to end programming
or move the cursor with the  or  to
“YES

”. This will allow you to enter another
tier to this program. Repeat steps 6-14 to
program second tier.

”. Select

YES NO

TIER 1

COOKING CURVE:

 ACCEPT
 ENTER

ACTION DISPLAY

Step 16. After programming the last tier, select “NO”

when asked “CONTINUE TO NEXT TIER”
the computer will automatically advance the
screen to program more products. If no
other products need to be programmed,
select “CANCEL” three times to advance
screen to the boot up screen.

 CREATE NEW PRODUCT

 EDIT PRODUCT

 DELETE PRODUCT

 EDIT PRODUCT

ACTION DISPLAY

CONTINUE TO NEXT TIER

USE  KEYS TO SELECT

APPLE

TEMP: 320F TIME: 00:45:00

FAN: HI RATE:

80 %

100 %

Step 17. You may now preheat the oven for any

products you have programmed.

Step 18. Select:

 Run oven

 RUN OVEN

 TIME / DATE / PROGRAM

TIME DATE TEMP STATUS

12:00 01/01/01 325 STANDBY

27

OPERATIONS

Convection ovens constantly circulate air over the product. This strips away the thin layer
of moisture and cool air from the top of the product. Heat penetrates more quickly.
Cooking times are shortened and cooking temperatures are usually reduced.
To convert standard deck oven recipes to convection oven recipes, reduce the temperature
50 °F and the time by 25%. Make adjustments as necessary, depending upon your results.
The lower the temperature the more even the bake.
Check the product halfway through the baking cycle. Look through the door windows.
Opening the oven door is not recommended.
If products are brown on the outside and not done on the inside, too high a temperature is
being used. Decrease the temperature 15-25 °F.
If products are pulling to the edge of pans or spilling, the oven is not leveled or the pans are
warped. Correct as necessary.
Load each shelf evenly. Spaces should be maintained equally between the pan and walls.
Front and back. This will allow an even distribution of airflow.

BAKING

Most baking should be done with the vent closed. Open the vent only with high moisture
products to avoid seepage around the front of the door.
Always weigh your product. This will give you a more consistent size, color and quality.
Center the pan in the oven. The better the air flow around the product, the better the bake.
The convection oven is a mechanical piece of equipment. The same control settings will
always give the same results. If the results vary, problems may be because of preparation,
not the oven.

GENERAL

LOADING

Place product as close to oven as practical. Open oven doors and load quickly but
carefully.
If only one pan is required, load on center shelf. If two pans are required, load on second
and fourth shelf. If three pans are required, load on top shelf, bottom shelf, and center
shelf. If four pans are required, load on top shelf, bottom shelf, and middle two shelves. If
five shelves are required, space evenly in oven. (See page 28 for more detail)

UNLOADING

It is a characteristic of all convection ovens to unload the top shelf before the bottom
shelves. The rising of heat and the hot oven ceiling causes the top shelf to bake quicker.
This characteristic is more pronounced when baking at higher temperatures and/or for
prolonged periods of time.

28

GENERAL CONT’D

ONE PAN

TWO PAN

THREE PAN

FOUR PAN

FIVE PAN

29

TYPICAL OPERATION

GCCO-AP TYPICAL OPERATION SEQUENCE

ACTION RESULT

Turn power switch to ON. Control panel heat call light comes on.

Adjust proper temperature, between 140 & 450
degrees and allow to preheat up to 20 minutes.

Open oven doors and insert product, set timer up to
60 minutes.

Timer beeps continuously when done. Product should now be done.

Oven begins heating.

Timer begins counting down.

GCCO-T TYPICAL OPERATION SEQUENCE

ACTION RESULT

Turn power switch to ON.

Adjust proper temperature, between 140 & 450
degrees and allow to preheat up to 20 minutes.

Open oven doors and insert product, set timer up to
60 minutes.

Timer beeps continuously when done. Product should now be done.

Oven begins heating.

Timer begins counting down.

GCCO-SII TYPICAL OPERATION SEQUENCE

ACTION RESULT

Turn power switch to ON. Digital display reads “000””.

Press Temp button and use arrows to adjust to
proper Temp between 150 & 450.

Beeper will sound for 3 seconds when preheated.
Open doors and insert product.

Press Time Button and use arrows to adjust to
desired time. Press Start / Stop Button.

Beeper sounds continuously Press Start / Stop
Button.

Oven begins heating and displays “pre”.

Display will read preheated temperature.

Digital display will start countdown.

30

TYPICAL OPERATION CONT’D

GCCO-C TYPICAL OPERATION SEQUENCE

ACTION RESULT

Turn power switch to ON. Control panel comes on, display says “88888” and

then “ENTER”, motor starts.

Press a product button. Display says “PREHT” (Preheat), oven begins to heat

to the programmed temperature.

Beeper sounds briefly. Display says “READY”.

Open the oven doors and load the product. Close the
door and press the product button again.

Press the shelf button(s) which correspond to the
shelf positions which the product is loaded (A
equals the top shelf and E equals the bottom shelf).

Beeper sounds continuously. Display shows “DONE”, shelf button(s) flash.

Press the flashing shelf button(s). Beeper stops. Display shows “READY” if no other

Open oven door and remove the product, which
corresponds to flashing shelf button(s).

Beeper sounds briefly and display says “SHELF”.

Display shows a countdown timer and begins to
count toward zero.

shelves carry product or resume count down for
shelves that still have product cooking.

GCCO-PP TYPICAL OPERATION SEQUENCE

ACTION RESULT

Turn power switch to ON. Control panel comes on, display says “SELECT

PRODUCT OR READ/CLEAR TO PROGRAM.

Press a product button. Display says “PRODUCT X PREHEATING TO

XXX F”. Motor starts and oven begins preheating
to the programmed temperature.

Beeper sounds briefly. Display says “READY SELECT PRODUCT TO

START ”.

Open the oven doors and load the product. Close
the door and press the product button again.

Press the shelf button(s) which correspond to the
shelf positions just left, which the product is loaded
(A equals the top shelf and E equals the bottom
shelf).

Beeper sounds continuously. Display shows “DONE PRESS SHELF BUTTON

Press the flashing shelf button(s). Beeper stops. Display shows “READY SELECT

Open oven door and remove the product, which
corresponds to flashing shelf button(s).

Beeper sounds briefly and display says “SELECT
OVEN SHELVES PRODUCT X”.

Display shows a countdown timer and begins to
count toward zero.

X, REMOVE PRODUCT”, shelf button(s) flash.

PRODUCT TO START” if no other shelves carry

product or resume count down for shelves that still
have product cooking.

31

TYPICAL OPERATION CONT’D

GCCO-PT TYPICAL OPERATION SEQUENCE

ACTION RESULT

Press the on switch. Control panel comes on, display says “LANG, Run

Oven, Time Date Program.

Select “Run Oven”. Display will show a list of product to choose.

Select Product button next to Icon desired. Display says “Preheating to XXXF”.

Beeper sounds briefly. Display says “Ready”.

Select Product to start. Display shows possible product selection for that

temperature.

Select Product to start. Display says “Select shelf”.

Press Product button next to desired shelf. Display will show icon chosen and begin to count

down.

Beeper sounds continuously. Display shows “ DONE” press button and remove

product from that shelf.

Oven is ready for another product.

32

Power to oven light switch .
120/24-volt transformer energized.
24 volts to 6 (Johnson Control), TH (Channel Products), and ground of spark module.

Spark module begins sparking at pilot burner.

24 volts to pilot valve coil of combination gas valve.
Pilot valve opens.
Gas flows to pilot burner.
Pilot burner lights.

Pilot light confirmed by spark module.

12 to 13 micro amps on pin 4 (Johnson Control), and Sens (Channel products).
24 volts from pin 3 (Johnson Control) and MV (Channel products) to isolation transformer.
24-volt isolation transformer energizes.
24 volts to pins 9 and 7 of circuit board.
24 volts to motor relay through door switch and pulse-fan switch.
Motor relay closes energizing motor and closing centrifugal switch.

Temperature set on 12-position switch.

24 volts from circuit board to MV on combination valve through pulse-switch, centrifugal switch,
and over temperature thermostat.
Main burner ignites.

SEQUENCE OF OPERATION GCCO-T

Power switch turned to “ON” position.

Power to oven light switch .
120/24-volt transformer energized.
24 volts to 6 (Johnson Control), TH (Channel Products), and ground of spark module.

Spark module begins sparking at pilot burner.

24 volts to pilot valve coil of combination gas valve.
Pilot valve opens.
Gas flows to pilot burner.
Pilot burner lights.

Pilot light confirmed by spark module.

12 to 13 micro amps on pin 4 (Johnson Control), and Sens (Channel products).
24 volts from pin 3 (Johnson Control) and MV (Channel products) to isolation transformer.
24-volt isolation transformer energizes.
24 volts to pins 9 and 7 of circuit board.
24 volts to motor relay through door switch and pulse-fan switch.
Motor relay closes energizing motor and closing centrifugal switch.

Temperature set on 12-position switch.

24 volts from circuit board to MV on combination valve through pulse-switch, centrifugal switch,
and over temperature thermostat.
Main burner ignites.

SEQUENCE OF OPERATION GCCO-AP

33

Power switch turned to “ON” position.

Power to oven light switch .
120/24-volt transformer energized.
24 volts to TH, and ground of spark module.

Spark module begins sparking at pilot burner.

24 volts to pilot valve coil of combination gas valve.
Pilot valve opens.
Gas flows to pilot burner.
Pilot burner lights.

Pilot light confirmed by spark module.

12 to 13 micro amps on pin 4 (Johnson Control), and Sens (Channel products).
24 volts from pin 3 (Johnson Control) and MV (Channel products) to isolation transformer.
24-volt isolation transformer energizes.
24 volts to pins 1 and 2 of circuit board.
24 volts at motor out put (pin5) to ground.
24 volts to motor relay through door switch and pulse-fan switch.
Motor relay closes energizing motor and closing centrifugal switch.

Temperature set on circuit board.

24 volts at heat out put to ground.
24 volts from circuit board to MV on combination valve through pulse-switch, centrifugal switch,
and over temperature thermostat.
Main burner ignites.

SEQUENCE OF OPERATION GCCO-SII

34

Power switch turned to “ON” position.

Power to oven light switch.
120 volts to rows “A” and “B” of 24 pin terminal block.
120/24-volt transformer energized.
24 volts to rows “C” and “D” of 24 pin terminal block.
24 volts to common of back-up toggle switch.
24 volts to pin “A” on back-up relay.
24 volts to 6 (Johnson Control), TH (Channel Products), and ground of spark module.

Spark module begins sparking at pilot burner.

24 volts to pilot valve coil of combination gas valve.
Pilot valve opens.
Gas flows to pilot burner.
Pilot burner lights.

Pilot light confirmed by spark module.

12 to 13 micro amps on pin 4 (Johnson Control), and Sens (Channel products).
24 volts from pin 3 (Johnson Control) and MV (Channel products) to common of back-
up toggle switch.

Back-up toggle switch “OFF”.

Circuit 1

24 volts across “D” and TP4, TP5, and TP6.
24 volts to motor relay through door switch.
Motor centrifugal switch closes.
Circuit 2
24 volts to terminal “B” on back-up relay.
Back-up relay closes, energizing 120/12 volt transformer.
12 volts to TP1.
Computer starts.
Product selected from Control panel.
24 volts from TP5 through safety thermostat, through centrifugal switch in motor, to
main valve .coil of gas combination valve.
Main valve opens.
Gas flows to main burners.
Main burners light.

Back-up toggle switch “ON”.

Circuit 1

24 volts to motor relay.
Motor relay closes.
Motor centrifugal switch closes.
Circuit 2
24 volts to Back-up thermostat.
Temperature set on Back-up thermostat.
24 volts from Back-up thermostat through safety thermostat, through centrifugal switch
in motor to main valve coil of Gas combination valve.
Main valve opens.
Gas flows to main burners.
Main burners light.

SEQUENCE OF OPERATION GCCO-C

35

Oven plugged in.

120 VAC across “A” and “B” of 24 pin terminal block.
120 VAC across Common on light relay.
120 VAC across Common on cooling fan relay.
120 VAC to control transformer (120 / 24-12) and Component transformer (120 / 24).

Power switched to “ON” position.

24 VAC across JP1 and “C”.
24 VAC across “TH” and ground on spark module.
24 VAC across “PV” and ground on spark module.
24 VAC across “PV” on combination valve.
Pilot valve opens.
Pilot ignites.

Pilot confirmed.

12-13 micro-amps from “SENSE” on spark module.
24 VAC across “MV” on spark module.

Product selected.

24 VAC across JP12 and “C”.
24 VAC across motor relay coil.
Motor relay closes.
120 VAC to motor.

Motor starts.

24 VAC across “MV” to ground on spark module.
24 VAC across JP 2 to “C”.
24 VAC to “MV” on combination valve (through centrifical switch on motor).
Main valve opens.
Main burner ignites.

Back up toggle switch to “ON”.

24 VAC to “TH” on spark module.
24 VAC across “PV” on spark module to ground.
24 VAC to “PV” on combination valve.
Pilot valve opens.
Pilot ignites.

Pilot confirmed.

12-13 micro-amps from “SENSE” on spark module.
24 VAC across “MV” on spark module.
24 VAC to motor relay.
Motor relay closes.
120 VAC to motor.

Motor Starts.

24 VAC across “MV” to ground on spark module.
24 VAC across JP 2 to “C”.
24 VAC to “MV” on combination valve (through centrifical switch on motor).
Main valve opens.
Main burner ignites.

SEQUENCE OF OPERATION GCCO-PP/PT

36

NO MOTOR

PROBABLE CAUSE CORRECTIVE ACTION

Defective power switch  Check power switch for normal operation. Replace as necessary.
Defective Transformer  Check Transformer for normal operation.

Gas supply turned off  Turn gas supply on and check for proper gas pressure. 5” water

Defective Pilot  Perform the following “trial ignition” and look and listen for spark:

Spark observed  Check for 24 VAC at pilot valve.

No spark observed Turn oven on. Refer to wiring diagram and check for 24 VAC at the TH

TROUBLESHOOTING GCCO-T

column for natural gas and 10” water column for propane.

Attempt to light the pilot burner. If the burner does not ignite
after 30 seconds, cycle power and repeat “trial ignition”. The
pilot may require several trials for ignition to bleed air from the
gas piping. After the ignition attempt, pilot should only require
2-5 seconds for normal start-up.

If 24 VAC is measured, turn oven off:

 Check for pilot burner orifice blockage. Clean and repair as

necessary.

 Perform trial ignition, as described in above section.

 Replace gas valve.

If 24 VAC is not measured:

 Check for 24 VAC at PV on spark module.

 Check continuity on wire between PV on spark module and Pilot

Valve.

terminal on the spark module.

If 24 VAC is measured. Turn oven off:

 Check large orange wire from igniter module to pilot burner for

continuity, and for insulation breaks.

 Replace wire as necessary.

 Check spark electrode and hood of pilot burner.
 Check spark gap. Clean and re-gap if necessary.

 Check pilot burner for any evidence of moisture. Dry pilot if

necessary.

 Replace spark module if above checks do not correct problem.

If 24 VAC is not measured. Turn oven off:

 Check 120/24 VAC transformer for 18.9 Ω on the primary coil and 1

Ωon the secondary coil.

 Turn unit back on and check primary coil for 120 VAC and secondary

for 24 VAC.

 Replace transformer.

37

TROUBLESHOOTING GCCO-T CONT’D

PROBABLE CAUSE CORRECTIVE ACTION

Igniter continues to spark after
pilot is lit

Defective Module  Confirm that there is a pilot ignition.

Defective Isolation Transformer  Confirm that transformer is getting voltage.

Defective Door switch  Confirm that Door switch is getting voltage.

Defective Motor relay  Confirm that motor relay is getting power.

Defective Motor  Confirm that motor is getting power.

NO HEAT

NOTE: The motor needs to be operational before the oven will start heating.

PROBABLE CAUSE CORRECTIVE ACTION

 Check pilot for strong flame and good contact with sensor.

 Check sense wire for 12 to 13 micro amps on spark module. (Johnson

Control spark modules use “#4” terminal and Channel spark modules
use “Sense” terminal).

 Turn oven off and check sense wire for continuity.
 Replace sense wire or spark module as necessary.

 Check for 24VAC at “MV” to ground.

 Check transformer for normal operation.

 Check door switch for normal operation.

 Check motor relay for normal operation. (24 VAC 39 Ω)

 Check motor for normal operation. (HIGH: P1-T7,T4) (LOW: P1-T9)

Defective Thermostat

Defective Centrifugal Switch  Confirm that when motor is running that there is continuity through

Defective Hi Limit Thermostat  Check Hi Limit Thermostat for continuity.

Defective Solenoid Valve  Confirm that Valve is getting voltage.

Plugged Main Burner Orifice  Clean orifice.

 Confirm that Thermostat is getting 24 VAC. Measure between

Thermostat terminal and “D” on the terminal block

If voltage is not present:

 Check Transformer for normal operation.

If voltage is present:

 Check thermostat for continuity.
 Replace as necessary.

Centrifugal switch.

 Check Valve for normal operation.

38

NO MOTOR

PROBABLE CAUSE CORRECTIVE ACTION

Defective power switch  Check power switch for normal operation. Replace as necessary.
Defective Transformer  Check Transformer for normal operation.

Gas supply turned off  Turn gas supply on and check for proper gas pressure. 5” water

Defective Pilot  Perform the following “trial ignition” and look and listen for spark:

Spark observed  Check for 24 VAC at pilot valve.

No spark observed Turn oven on. Refer to wiring diagram and check for 24 VAC at the TH

TROUBLESHOOTING GCCO-AP

column for natural gas and 10” water column for propane.

Attempt to light the pilot burner. If the burner does not ignite
after 30 seconds, cycle power and repeat “trial ignition”. The
pilot may require several trials for ignition to bleed air from the
gas piping. After the ignition attempt, pilot should only require
2-5 seconds for normal start-up.

If 24 VAC is measured, turn oven off:

 Check for pilot burner orifice blockage. Clean and repair as

necessary.

 Perform trial ignition, as described in above section.

 Replace gas valve.

If 24 VAC is not measured:

 Check for 24 VAC at PV on spark module.

 Check continuity on wire between PV on spark module and Pilot

Valve.

terminal on the spark module.

If 24 VAC is measured. Turn oven off:

 Check large orange wire from igniter module to pilot burner for

continuity, and for insulation breaks.

 Replace wire as necessary.

 Check spark electrode and hood of pilot burner.
 Check spark gap. Clean and re-gap if necessary.

 Check pilot burner for any evidence of moisture. Dry pilot if

necessary.

 Replace spark module if above checks do not correct problem.

If 24 VAC is not measured. Turn oven off:

 Check 120/24 VAC transformer for 18.9 Ω on the primary coil and 1

Ωon the secondary coil.

 Turn unit back on and check primary coil for 120 VAC and secondary

for 24 VAC.

 Replace transformer.

39

TROUBLESHOOTING GCCO-AP

PROBABLE CAUSE CORRECTIVE ACTION

Igniter continues to spark after
pilot is lit

Defective Module  Confirm that there is a pilot ignition.

Defective Isolation Transformer  Confirm that transformer is getting voltage.

Defective Door switch  Confirm that Door switch is getting voltage.

Defective Motor relay  Confirm that motor relay is getting power.

Defective Motor  Confirm that motor is getting power.

NO HEAT

NOTE: The motor needs to be operational before the oven will start heating.

PROBABLE CAUSE CORRECTIVE ACTION

 Check pilot for strong flame and good contact with sensor.

 Check sense wire for 12 to 13 micro amps on spark module. (Johnson

Control spark modules use “#4” terminal and Channel spark modules
use “Sense” terminal).

 Turn oven off and check sense wire for continuity.
 Replace sense wire or spark module as necessary.

 Check for 24VAC at “MV” to ground.

 Check transformer for normal operation.

 Check door switch for normal operation.

 Check motor relay for normal operation. (24 VAC 39 Ω)

 Check motor for normal operation. (HIGH: P1-T7,T4) (LOW: P1-T9)

Defective Probe  Confirm that probe is operating properly. (See Technical Data)

Defective Circuit board  Confirm that Heat Call light is on.

If no light is detected:
 Check 12-position switch for normal operation. (See Technical Data)

If light is detected:
 Check for 24VAC across heat output and “D” on 12 Pole terminal.

If voltage is not present:
 Replace Circuit board.

If voltage is present:

 Check over temperature thermostat for proper operation.

 Check door switch for normal operation.

Defective Centrifugal Switch  Confirm that when motor is running that there is continuity through

Centrifugal switch.

Defective Hi Limit Thermostat  Check Hi Limit Thermostat for continuity.
Defective Solenoid Valve  Confirm that Valve is getting voltage.

 Check Valve for normal operation.

Plugged Main Burner Orifice  Clean orifice.

40

NO MOTOR

PROBABLE CAUSE CORRECTIVE ACTION

Defective power switch  Check power switch for normal operation. Replace as necessary.
Defective Transformer  Check Transformer for normal operation.

Gas supply turned off  Turn gas supply on and check for proper gas pressure. 5” water

Defective Pilot  Perform the following “trial ignition” and look and listen for spark:

Spark observed  Check for 24 VAC at pilot valve.

TROUBLESHOOTING GCCO-SII

column for natural gas and 10” water column for propane.

Attempt to light the pilot burner. If the burner does not ignite
after 30 seconds, cycle power and repeat “trial ignition”. The
pilot may require several trials for ignition to bleed air from the
gas piping. After the ignition attempt, pilot should only require
2-5 seconds for normal start-up.

If 24 VAC is measured, turn oven off:

 Check for pilot burner orifice blockage. Clean and repair as

necessary.

 Perform trial ignition, as described in above section.

 Replace gas valve.

If 24 VAC is not measured:

 Check for 24 VAC at PV on spark module.

 Check continuity on wire between PV on spark module and Pilot

Valve.

No spark observed Turn oven on. Refer to wiring diagram and check for 24 VAC at the TH

terminal on the spark module.

If 24 VAC is measured. Turn oven off:

 Check large orange wire from ignitor module to pilot burner for

continuity, and for insulation breaks.

 Replace wire as necessary.

 Check spark electrode and hood of pilot burner.
 Check spark gap. Clean and regap if necessary.

 Check pilot burner for any evidence of moisture. Dry pilot if

necessary.

 Replace spark module if above checks do not correct problem.

If 24 VAC is not measured. Turn oven off:

 Check 120/24 VAC trasformer for 18.9 Ω on the primary coil and 1

Ωon the secondary coil.

 Turn unit back on and check primary coil for 120 VAC and secondary

for 24 VAC.

 Replace transformer.

41

TROUBLESHOOTING GCCO-SII CONT’D

PROBABLE CAUSE CORRECTIVE ACTION

Igniter continues to spark after
pilot is lit

Defective Module  Confirm that there is a pilot ignition.

Defective Isolation Transformer  Confirm that transformer is getting voltage.

Defective Circuit board  Check for 24 VAC across Motor output on board and “D” on 12-

 Check pilot for strong flame and good contact with sensor.

 Check sense wire for 12 to 13 micro amps on spark module. (Johnson

Control spark modules use “#4” terminal and Channel spark modules
use “Sense” terminal).

 Turn oven off and check sense wire for continuity.
 Replace sense wire or spark module as necessary.

 Check for 24VAC at “MV” to ground.

 Check transformer for normal operation.

position terminal block.

If no voltage is present:

 Confirm that voltage is coming in from transformer.

 Replace circuit board.

If voltage is present:

 Check motor relay for normal operation. (24 VAC 35Ω)

 Check door switch for normal.

 Check motor for normal operation. (See Technical Data)

NO HEAT

NOTE: The motor needs to be operational before the oven will start heating.

PROBABLE CAUSE CORRECTIVE ACTION

Defective Probe  Confirm that probe is operating properly. (See Technical Data)

Defective Circuit board  Confirm that Heat Call light is on.

If no light is detected:
 Check 12-position switch for normal operation. (See Technical Data)

If light is detected:
 Check for 24VAC across heat output and “D” on 12 Pole terminal.

If voltage is not present:
 Replace Circuit board.

If voltage is present:

 Check over temperature thermostat for proper operation.
 Check door switch for normal operation.

Defective Centrifugal Switch  Confirm that when motor is running that there is continuity through

Centrifugal switch.

Defective Hi Limit Thermostat  Check Hi Limit Thermostat for continuity.

Defective Solenoid Valve  Confirm that Valve is getting voltage.

 Check Valve for normal operation.

Plugged Main Burner Orifice  Clean orifice.

42

TROUBLESHOOTING GCCO-C

 To help troubleshoot the oven you should perform the following “Manual Override” test:
 Open drop down door located on the lower right side, directly below front panel.
 Turn back up toggle (on/off) switch to “on” position.
 Turn main power switch to “on” position.
 Check oven for normal operation.

NO DISPLAY

PROBABLE CAUSE CORRECTIVE ACTION

Power switch is not turned on

Defective power switch

Defective back-up relay

Gas supply turned off

Pilot light fails to light

Spark observed

 Turn power switch on.
 Check power switch for normal operation. Replace as necessary.
 Check relay for normal operation.

 Check coil for 24 VAC.

If 24 VAC is measured. Turn oven off and:

 Check coil for 80 Ω.

 Replace as necessary.

If 24 VAC is not measured.

 Verify that manual override switch is in “off” position.

 Check manual override switch for normal operation.
 Check wires for any shorts.

 Turn gas supply on and check for proper gas pressure. 5” water

column for natural gas and 10” water column for propane.

 Perform the following “trial ignition” and look and listen for spark:

Attempt to light the pilot burner. If the burner does not ignite
after 30 seconds, cycle power and repeat “trial ignition”. The
pilot may require several trials for ignition to bleed air from the
gas piping. After the ignition attempt, pilot should only require
2-5 seconds for normal start-up.

 Check for 24 VAC at pilot valve.

If 24 VAC is measured, turn oven off:
 Check for pilot burner orifice blockage. Clean and repair as

necessary.

 Perform trial ignition, as described in above section.
 Replace gas valve.

If 24 VAC is not measured:

 Check for 24 VAC at PV on spark module.
 Check continuity on wire between PV on spark module and Pilot

Valve.

43

TROUBLESHOOTING GCCO-C CONT’D

PROBABLE CAUSE CORRECTIVE ACTION

No spark observed

Igniter continues to spark
after pilot is lit

Defective back-up relay

Turn one on. Refer to wiring diagram and check for 24 VAC at the TH
terminal on the spark module.

If 24 VAC is measured. Turn oven off:

 Check large orange wire from igniter module to pilot burner for

continuity, and for insulation breaks.

 Replace wire as necessary.

 Check spark electrode and hood of pilot burner.

 Check spark gap. Clean and re-gap if necessary.
 Check pilot burner for any evidence of moisture. Dry pilot if

necessary.

 Replace spark module if above checks do not correct problem.

If 24 VAC is not measured. Turn oven off:

 Check 120/24 VAC transformer for 18.9 Ω on the primary coil and 1

Ωon the secondary coil.

 Turn unit back on and check primary coil for 120 VAC and secondary

for 24 VAC.

 Replace transformer.
 Check pilot for strong flame and good contact with sensor.
 Check sense wire for 12 to 13 micro amps on spark module. (Johnson

Control spark modules use “#4” terminal and Channel spark modules
use “Sense” terminal).

 Turn oven off and check sense wire for continuity.
 Replace sense wire or spark module as necessary.

 Check relay for normal operation (on GCCO ovens relay will be

energized in computer mode).

 Check coil for 24 VAC.

If 24 VAC is measured. Turn oven off and:

 Check coil for 80 Ω.
 Replace if necessary.

If 24 VAC is not measured.

 Verify that back up switch is in “off” position.
 Check back-up switch for normal operation. (DPDT)

 Check any wires for short.

44

TROUBLESHOOTING GCCO-C CONT’D

PROBABLE CAUSE CORRECTIVE ACTION

Defective control transformer
(12 VAC).

Defective rectifier

Note: Display should now be operating.

 Check transformer for normal operation.

 Check primary coil for 120 VAC and 154.1 Ω. Check secondary coil

for no less than 10.5 VAC and 1 Ω.

If voltage is measured on primary:

 Check for voltage on secondary.

 Replace transformer.

If voltage is not measured on primary:

 Check wires for any shorts.
 Check for no less than 10.5 VAC on TP1 and 5 VDC on TP2.

 If correct voltage is present at TP1 and present, but low at TP2

unplug both ribbon connections from CPU and re-measure at TP2.

 If voltage remains low at TP2 replace CPU (40102-311).

 If voltage at TP2 increased to 5 VDC when ribbon was unplugged,

plug ribbon back in to CPU and disconnect from Interface board.

 Re-measure at TP2.

 If voltage dropped to below 5 VDC replace ribbon cable (31110-01).
 If voltage remains at 5 VDC, plug ribbon back into Interface board

and measure for 5 VDC at TP3.

 If voltage is present at TP3 and display is still not on, press and hold

the R/C button on board if LED’s come on replace Interface board.

 If LED segment does not illuminate or the LED is blank, replace

LED.

45

NO FAN-Manual Mode

PROBABLE CAUSE CORRECTIVE ACTION

TROUBLESHOOTING GCCO-C CONT’D

Defective 120/24 VAC
transformer

Back-up relay not energizing

Motor contactor not
energized

No voltage across contactor
points

Defective motor

Note: Motor should now be operating.

 Check for 24 VAC on “C” and “D” of the terminal block.

If 24 VAC is not measured: Turn off and:

 Check secondary coil for 1 Ω.

 Check primary coil for 18.9 Ω.
 Replace transformer.

If 24 VAC is measured: Turn off and:

 Check back-up relay for normal operation.
 Check for 24 VAC on relay coil.

If 240 VAC is measured: Turn unit off and:

 Check back-up relay coil for 80 Ω.
 Replace if defective.

If 240 VAC is not measured:

 Check back-up switch (SPDT) for normal operation.
 Replace if defective.

 Check for 24 VAC at contactor or relay coil.

If 24 VAC is not measured: Turn oven off and:

 Check door switch for normal operation.

 Check door switch for continuity.
 Replace or adjust door switch.

If 24 VAC is measured: Turn unit off and:

 Check contactor coil for continuity.
 Replace if defective.

 Check 120 VAC across “C” terminals of contactor.

If 120 VAC is not measured:

 Check connection to main contactor (heat contactor).

If 208/240 VAC is measured:

 Check across “NO” contacts. Should have 120 VAC.
 Replace if defective.
 Check for 120 VAC at motor.

If 120 VAC is measured, Turn oven off:

 Check motor winding’s for continuity.

 Replace if defective.

If120 VAC is not measured:

 Check wiring between motor and contactor.

46

NO MOTOR COMPUTER MODE

PROBABLE CAUSE CORRECTIVE ACTION

TROUBLESHOOTING GCCO-C CONT’D

No 24 VAC on Interface
board

 Check for 24 VAC at TP4 to common (“D”).

If 24 VAC is not measured:

 Confirm that back up relay is energizing.
 Replace if defective.

If 24 VAC is measured:

 Check for 24 VAC at TP5.
 Replace Interface board if defective.

NO HEAT MANUAL MODE

NOTE: Fan must be operating before trouble shooting No heat.

PROBABLE CAUSE CORRECTIVE ACTION

Pilot burner fails to light

Spark observed

 Perform the following “trial ignition” and look and listen for spark:

Attempt to light the pilot burner. If the burner does not ignite
after 30 seconds, cycle power and repeat “trial ignition”. The
pilot may require several trials for ignition to bleed air from the
gas piping. After the initial attempt pilot should only require 2-5
seconds for normal start up.

 Check for 24 VAC at pilot valve.
If 24 VAC is measured, turn oven off:
 Check for pilot burner orifice for blockage. Clean and repair as

necessary.

 Perform trial ignition as described in above section.
 Replace gas valve.

If 24 VAC is not measured:

 Check for 24 VAC at PV on spark module.
 Check continuity on wire between PV on spark module and Pilot

Valve.

47

TROUBLESHOOTING GCCO-C CONT’D

PROBABLE CAUSE CORRECTIVE ACTION

No Spark observed

Igniter continues to spark
after pilot is lit

Defective thermostat

Defective over-temp
thermostat

Defective Centrifugal switch

Turn oven on. Refer to wiring diagram and check for 24 VAC at the TH
terminal on the spark module.

If 24 VAC is measured, Turn unit off and:
 Check large orange wire from igniter module to pilot burner for

continuity, and for insulation breaks.

 Replace wire as necessary.

 Check spark electrode and hood of pilot burner.

 Check spark gap. Clean and re-gap if necessary.
 Check pilot burner for any evidence of moisture. Dry pilot if

necessary.

 Replace spark module if above checks do not correct problem.
If 24 VAC is not measured, Turn oven off and:

 Check 120/24 VAC transformer of 18.9 Ω on the primary coil and 1

Ω on the secondary coil.

 Turn unit back on and check primary coil for 120 VAC and secondary

for 24 VAC.

 Replace if necessary.
 Check pilot for strong flame and good contact with sensor.

 Check sense wire for 12 to 13 amps on spark module. (Johnson

Control spark modules use “4” terminal and Channel spark modules
use “sense” terminal).

 Turn oven off and check sense wire for continuity.

 Replace sense wire or spark module as necessary.
 Turn unit off and check for continuity while cycling thermostat on

and off.

 Replace if defective.
 Check for 24 VAC on wire # 55 on MV of spark module to ground.

If 24 VAC is not measured, Turn oven off and:

 Check for continuity through over-temp thermostat.

 Replace if defective.

If 24 VAC is measured, Turn oven off and:

 Check for continuity on the gas solenoid valve.

 Replace if defective.
 Check for 24 VAC on wire # 55 on MV of spark module to ground.

If 24 VAC is not measured:

 Check for 24 VAC on red wire coming out of motor to ground.
 Replace if defective.

NOTE:

turning thermostat off wile oven is still on.
If 24 VAC is measured, Turn oven off and:

 Check for continuity on the gas solenoid valve.

 Replace if defective.

You can check for continuity through Centrifugal switch by

48

NO HEAT Computer Mode

PROBABLE CAUSE CORRECTIVE ACTION

TROUBLESHOOTING GCCO-C CONT’D

No 24 VAC on Interface
board

DISPLAY LOCKS UP

PROBABLE CAUSE CORRECTIVE ACTION

“Help” in display

“88888” stuck in display

Display has shelf “A”

 Check for 24 VAC at TP4 to ground.

If 24 VAC is not measured:

 Check back-up switch for normal operation.

If 24 VAC is measured:

 Check for 24 VAC at TP6.
 Replace Interface board if defective.

 Check probe for proper resistance.

 Check that probe connections are secure.
 Push “TEMP” button on control board and check to see if temperature

rapidly descends. If temp does descend rapidly, replace ribbon cable.

 Check to see that contactors/relays are not stuck in the closed

position.

 Replace contactor if defective.

 Check for foreign objects keeping contactor closed.
 Check for stuck button by pressing any button.

If computer beeps or chirps:

 Check control panel transformer (12 VAC) for proper operation.

 Check TP1 for at least 10.5 VAC.

 Check TP2 for at least 4.99 VDC.
 Check TP3 for at least 4.97 VDC.

If computer does not beep or chirp:

 Check each button for movement.

 Check that panel label has not been damaged in any way.

 Replace button if defective.
 Replace panel label.

 Read Programming Codes.

49

TROUBLESHOOTING GCCO-PP / -PT

 To help troubleshoot the oven you should perform the following “Manual Override” test:
 Open drop down door located on the lower right side, directly below front panel.
 Turn back up toggle (on/off) switch to “on” position.
 Turn main power switch to “on” position.
 Check oven for normal operation.

FAILED IGNITION

PROBABLE CAUSE CORRECTIVE ACTION

Defective Power Switch (-PP
only)

Defective Power Switch
output on circuit board
(JP37)

Defective Ignition output

Defective component
transformer

Defective Spark Module

Defective pilot valve

Defective flame sensor

 Confirm that toggle switch is getting correct voltage.
 Check power switch for normal operation.

 Confirm that JP37 has 5VDC in the off position and nominal voltage

in the on position.

 If JP37 has a constant 5VDC check toggle switch for normal

operation.

 Check for 24VAC at JP1 to Common (C)

If no voltage is present:

 CPU is operating properly.

If voltage is present:

 Output has failed.

 Confirm that 208/240VAC is feeding primary coil.
 Confirm that 24VAC is at secondary coil.

 Check for 24VAC at TH.

If no voltage is present:

 Check component transformer.

If voltage is present:

 Check for pilot ignition.
 Replace spark module.

 Check for 24VAC at pilot valve.

If no voltage is present:

 Check component transformer.

If voltage is Present:

 Confirm valve is operational.
 Check flame sensor for 12 to 13 micro amps.

 Replace flame sensor.

Plugged orifice

IMPORTANT NOTICE: Power must be disconnected at source when disconnecting any ribbon cable or any
connector from CPU or Display. Failure to do so will result in damage to the Display board and CPU.

 Clean orifice.

50

NO DISPLAY

PROBABLE CAUSE CORRECTIVE ACTION

TROUBLESHOOTING GCCO-PP / -PT CONT’D

Defective Power Switch (-PP
only)

Defective Power Switch
output on circuit board
(JP37)

Defective Control
Transformer

Defective Display

 Confirm that toggle switch is getting correct voltage.
 Check power switch for normal operation.

 Confirm that JP37 has 5VDC in the off position and nominal voltage

in the on position.

 If JP37 has a constant 5VDC check toggle switch for normal

operation.

 Confirm that 208/240VAC is feeding primary coil.

 Confirm that 24VAC and 12VAC is at JP40 (24VAC across solid

yellow wires and 12VAC from one solid yellow wire to yellow with
red stripe).

 Check ribbon cable connections.

 Confirm that voltage is present at JP40.

If no voltage is present:
 Replace control transformer.

If voltage is present:

 Confirm that CPU has 5VDC at TP1 (this means that the CPU is

getting correct voltage).

 Confirm that CPU has 12VDC at TP2 (this means that the CPU is

sending out the correct voltage).

If no voltage is present:

 Replace CPU.

If voltage is present:

 Replace display.

51

NO MOTOR, MANUAL MODE

PROBABLE CAUSE CORRECTIVE ACTION

TROUBLESHOOTING GCCO-PP / -PT CONT’D

Defective back-up toggle
switch

Defective back-up relay

Defective component
transformer

Defective motor relay

Defective motor

 Confirm that toggle switch is in the “ON” position.
 Check toggle switch for normal operation.

 Check for 24VAC at relay coil.

If no voltage is present:

 Confirm that points are making.

If voltage is present:

 Replace relay.

 Confirm that 120VAC is feeding primary coil.

 Confirm that 24VAC is at secondary coil.

 Check for 24VAC at relay coil.

If no voltage is present:

 Confirm that points are making.

If voltage is present:

 Replace relay.

 Check for 120VAC across P1 and T7/T4.

If no voltage is present:

 Confirm that wires have continuity.

If voltage is present:

 Replace motor.

NO MOTOR, COMPUTER MODE

IMPORTANT NOTICE: Before trying to trouble shoot “No Motor in Computer Mode” confirm that motor is

operational in “Manual Mode”.

PROBABLE CAUSE CORRECTIVE ACTION

Defective output on CPU
board

 Check for 24VAC at JP12 for high or JP13 for low (while oven is

calling for heat).

If no voltage is present:

 Board is operating correctly.

If voltage is present:

 Replace CPU.

52

NO HEAT, MANUAL MODE

PROBABLE CAUSE CORRECTIVE ACTION

TROUBLESHOOTING GCCO-PP / -PT CONT’D

Defective back-up toggle
switch

Defective back-up relay

Defective component
transformer

Failed Ignition

Defective Thermostat

 Confirm that toggle switch is in the “ON” position.

 Check toggle switch for normal operation.

 Check for 120VAC at relay coil.

If no voltage is present:

 Confirm that points are making.

If voltage is present:

 Replace relay.

 Confirm that 120VAC is feeding primary coil.

 Confirm that 24VAC is at secondary coil.

 See Failed Ignition portion of this manual.

 Check for 24VAC at MV on the spark modual to ground.

If no voltage is present:

 Confirm that pilot is lit.

 Replace as necessary.

If voltage is present:

 Check thermostat for normal operation.

 Confirm that thermostat has 24VAC.

If no voltage is present

Defective centrifugal switch in
motor

Defective main valve

 Check component transformer and wiring for normal operation.

If voltage is present

 Check thermostat for normal operation. Replace as necessary.

 Disconnect centrifugal switch and check of continuity while the

motor is running.

If no continuity is present:

 Replace motor.

If continutiy is present:

 Check thermostat for normal operation.

 Check wires
 Check for 24VAC across valve.

If no voltage is present:

 Confirm that wires have continuity.

If voltage is present:

 Replace valve.

53

TROUBLESHOOTING GCCO-PP / -PT CONT’D

NO HEAT, COMPUTER MODE

IMPORTANT NOTICE: Before trying to trouble shoot “No Heat in Computer Mode” confirm that the oven heats in

“Manual Mode”.

PROBABLE CAUSE CORRECTIVE ACTION

Defective output on CPU
board

ANOMALIES

PROBABLE CAUSE CORRECTIVE ACTION

Display will intermittently
blank out

Intermittently over heats or
under cooks

 Check for 24VAC at JP2 (while oven is calling for heat).

If no voltage is present:

 Board is operating correctly.

If voltage is present:

 Replace CPU.

 Check ribbon cable for good connections
 Check panel label buttons and confirm that none of the domes are

collapsed.

If domes are collapsed:

 Replace panel label.
 Check probe for proper resistance.

 Check ribbon connection for good connection.

 Check probe for good connection.

54

TECHNICAL DATA

TRANSFORMER RESISTANCE

TRANSFORMER Input Primary Secondary Output

 120/24 Volt 120 Volt

 120/12 Volt 120 Volt

 24/24 Volt 24 Volt

18.9 Ω 1Ω

154.1 Ω 1 Ω

2.7 Ω 3.4 Ω

24 Volt

12 Volt

24 Volt

CONTACTOR RESISTANCE

CONTACTOR Coil

 3 Pole 24 Volt coil

 2 Pole 24 Volt coil (P & B) (PP & PT motor)

6 Ω

35 Ω

RELAY RESISTANCE

RELAY Coil

 24 VAC

82 Ω

OVER-TEMP THERMOSTAT

OVER-TEMP

 Wires Normally closed

DOOR SWITCH

 Check switch between “COM” (common) and “NO” (normally open) contacts, insure switch closes approximately 3 to 4

inches before door closes.

BLOWER FAN

 Blower fan will rotate clockwise and should have a 5/8“ gap between it and the back wall of the can.

AUTO/BYPASS SWITCH

The Auto / Bypass and Energy switch are located below the controls behind a pull down access panel

 Auto/Bypass switch Normally in “OFF”

power to the computer and allow use of the back-up
thermostat.

 Energy switch Normally in “HIGH”

PROVIDE 8.25 kW heat. Not provided on Steam
convection ovens.

. The “ON” position will interrupt

for 11 kW heats. “LOW” WILL

55

GAS VALVE

 Gas Valve Coil
 24 Volt input

PV 28 Ω MV 28 Ω

SPECIFACTIONS

TECHNICAL DATA CONT’D

BTU’S W/C

MODEL

NG LP

GCCO 55,000 55,000 One 1/2” NPT One 120 VAC, 7.1A 500 LBS 5” 10”

2GCCO 110,000 110,000 Two 1/2” NPT Two 120 VAC, 7.1A 1000 LBS 5” 10”

GCCO-XD 60,000 60,000 One 1/2” NPT One 120 VAC, 7.1 A 575 LBS 5” 10”

2GCCO-XD 120,000 120,000 Two 1/2” NPT Two 120 VAC, 7.1A

GAS

CONNECTION

ELECTRICAL CONN.

(SINGLE PAHCE)

WEIGHT

1150 LBS

NG LP

5” 10”

GCCO–PT / PP COOKING CURVE CONVERSION

Old Style Purple New Style Platinum /

Purple Plus

0 0%
1 17%
2 26%
3 40%
4 50%
5 56%
6 63%
7 71%

56

TECHNICAL DATA CONT’D

PROBE RESISTANCE

TEMP RESISTANCE VOLT DROP TEMP RESISTANCE VOLT DROP

70° 556 Ω

80° 569 Ω

90° 583 Ω

100° 596 Ω

110° 610 Ω

120° 623 Ω

130° 637 Ω

140° 651 Ω

150° 665 Ω

160° 678 Ω

170° 694 Ω

180° 709 Ω

190° 724 Ω

200° 739 Ω

210° 754 Ω

220° 769 Ω

1.11

1.14

1.17

1.19

1.22

1.25

1.27

1.3

1.33

1.36

1.39

1.42

1.45

1.48

1.51

1.54

290° 881 Ω

300° 897 Ω

310° 914 Ω

320° 931 Ω

330° 948 Ω

340° 965 Ω

350° 983 Ω

360° 1000 Ω

370° 1018 Ω

380° 1036 Ω

390° 1054 Ω

400° 1072 Ω

410° 1090 Ω

420° 1109 Ω

430° 1127 Ω

440° 1146 Ω

1.76

1.79

1.83

1.86

1.90

1.93

1.97

2.00

2.04

2.07

2.11

2.14

2.18

2.22

2.25

2.29

230° 785 Ω

240° 800 Ω

250° 816 Ω

260° 832 Ω

270° 848 Ω

280° 864 Ω

Probe is factory checked at 350 °F. Must be completely disconnected from circuit board when measuring

probe resistance. Display will read “HELP” if probe is open or unplugged. Any probe resistance can be

multiplied by 2 milli-amps (.002) to determine voltage drop.

1.57

1.60

1.63

1.66

1.70

1.73

NOTE

57

450° 1165 Ω

460° 1184 Ω

470° 1204 Ω

480° 1223 Ω

490° 1243 Ω

500° 1263 Ω

2.33

2.37

2.41

2.45

2.49

2.53

TECHNICAL DATA CONT’D

GCCO-C MODEL STRAPPING

The Front Control panel of the Lang “Purple” computer must be configured to match the model of oven it is being installed
in. To configure the front control panel, you must change the arrangement of the Strapping Bars located at the bottom of
the circuit board just above the ribbon connection. Each model has its own strapping configuration, which must
service technician. Follow the diagram below for the proper strapping configuration.

be set by the

POWER SWITCH

BACK OF CIRCUIT

BOARD

ECCO-C

ECCO-STM

GCCO-C

GCCO-STM

8-PIN CONNECTOR

PROBE CONNECTION

RIBBON CONNECTOR

58

EHS-C

GHS-C

GCCO-C TEST POINT LAYOUT

TECHNICAL DATA CONT’D

TP 1

TP5

TP7

59

GCCO-PP / -PT TEST POINT LAYOUT

MOTOR HIGH

MOTOR LOW

STEAM

POWER

GREEN

GREEN

GREEN

GREEN

RED

ORANGE

GREEN

BLUE

ECCO / GCCO LIGHTS

GREEN

GREEN

TECHNICAL DATA CONT’D

YELLOW

POWER

YELLOW / RED

YELLOW

YELLOW

YELLOW

YELLOW

YELLOW

YELLOW

YELLOW

PURPLE PLUS
POWER SWITCH

ECCO / GCCO
PURPLE PLUS
POWER SWITCH

DOOR SWITCH

BROWN

BROWN

60

WIREING DIAGRAM GCCO-T

61

WIRING DIAGRAM GCCO-AP

62

WIRING DIAGRAM GCCO-SII

63

WIRING DIAGRAM GCCO-C

64

WIRING DIAGRAM GCCO-PP

65

WIRING DIAGRAM GCCO-PT

66

PARTS LIST GCCO-T

DESCRIPTION PART NO.

Motor 1/3 HP 115/230 Volt with Momentary Switch (Before A-90068) 30200-15
Motor 1/3 HP 115 Volt 2 Speed (After C-90069) 30200-35
Micro Switch, Oven Door 30301-02
Switch, Toggle, On-On 30303-06
Switch, Toggle, Spring Return 30303-16
Thermostat Safety 490°F Open
Thermostat 450°F Oven
Terminal Strip 3 Pole 30501-02
Contactor 2 Pole 24 VAC (Before A-90068) 30701-04
Contactor 2 Pole 24 VAC (After C-90069) 30701-05
Timer Electric 1 Hour 24V (After C-90069) 30800-05
Timer Mechanical Long Ring (Before A-90068) 30801-01
Buzzer Electric Timer 24V (After C-90069) 30802-04
Power Cord with Molded Plug 31107-02
Transformer 115/24 VAC 31400-07
Pilot Light 28 VAC 31601-07
Lamp Socket 31602-04
Lamp 250 Volt 31603-09
Oven Lamp Lens (Watch Glass) 31604-01
Oven Lamp Lens Gasket 31604-02
Probe Pilot Flame Sensor 41100-07
Turnbuckle Assembly 50312-02
Door Left Hand 51100-45
Door Right Hand 51100-46
Panel Label (Before A-90068) 60301-91
Panel Label (After C-90069) 60301-101
Door Handle Assembly, Single Handle Oven 70603-15
Knob Time Control (Before A-90068) 70701-27
Knob Time/Temperature Control 70701-28
Window Assembly 71301-04
Blower Wheel 71500-05
Burner “U” Tube Steel 80002-05-1
Gas Manifold 80100-07
Pilot Burner Assembly 80201-14
Pilot Tube 60102-1381
Module Spark Ignitor NG & LP 80300-08
Orifice Main Burner .0890 #43 DRL NG 80400-13
Orifice Main Burner .0595 #53 DRL LP 80400-14
Orifice Pilot Burner .010 DRL LP 80401-05
Orifice Pilot Burner .018 DRL NG 80401-10
Valve Combination Gas 24 VAC NG (Before A-87433) 60101-63
Valve Combination Gas Conversion Kit NG to LP (Before A-87433) 80505-07
Valve Combination Gas 24 VAC NG (After A-87433) 80505-10
Valve Combination Gas Conversion Kit NG to LP (After A-87433) 80505-11

30401-09
30402-27

67

PARTS LIST GCCO-AP

DESCRIPTION PART NO.

Motor 1/3 HP 115 Volt 2 Speed 30200-35
Micro Switch, Oven Door 30301-02
Switch, Toggle, On-On 30303-06
Switch, Toggle, Spring Return 30303-16
Switch Temperature Control 12 Position 140-450°F
Thermostat Safety 490°F Open
Terminal Strip 3 Pole 30501-02
Contactor 2 Pole 24 VAC 30701-05
Timer Electric 1 Hour 24V 30800-05
Buzzer Electric Timer 24V 30802-04
Power Cord with Molded Plug 31107-02
Transformer 115/24 VAC 31400-07
Transformer Isolation 24V 31400-24
Pilot Light 28 VAC 31601-07
Lamp Socket 31602-04
Lamp 250 Volt 31603-09
Oven Lamp Lens (Watch Glass) 31604-01
Oven Lamp Lens Gasket 31604-02
Circuit Board Temperature Control 40101-19
Probe Pilot Flame Sensor 41100-07
Probe Temperature Sensor 41100-08
Turnbuckle Assembly 50312-02
Door Left Hand 51100-45
Door Right Hand 51100-46
Panel Label 60301-100
Knob Time/Temperature Control 70701-28
Window Assembly 71301-04
Blower Wheel 71500-05
Burner “U” Tube Steel 80002-05-1
Pilot Burner Assembly 80201-14
Pilot Tube 60102-1381
Module Spark Ignitor NG & LP 80300-08
Orifice Main Burner .0890 #43 DRL NG 80400-13
Orifice Main Burner .0595 #53 DRL LP 80400-14
Orifice Pilot Burner .010 DRL LP 80401-05
Orifice Pilot Burner .018 DRL NG 80401-10
Valve Combination Gas 24 VAC NG 80505-10
Valve Combination Gas Conversion Kit NG to LP 80505-11

30304-16
30401-09

68

PARTS LIST GCCO-SII

DESCRIPTION PART NO.

Motor 1/3 HP 115/230 Volt with Momentary Switch 30200-15
Motor 1/3 HP 115 Volt 2 Speed 30200-35
Micro Switch, Oven Door 30301-02
Switch, Toggle, On-On 30303-06
Switch, Toggle, Spring Return 30303-16
Thermostat Safety 490°F Open
Terminal Strip 3 Pole 30501-02
Contactor 2 Pole 24 VAC (Before F-90068) 30701-04
Contactor 2 Pole 24 VAC (After H-90069) 30701-05
Power Cord with Molded Plug 31107-02
Transformer 115/24 VAC 31400-07
Transformer 24 VAC Isolation (After H-90069) 31400-24
Transformer 115/12 VAC (After H-90069) 31400-26
Pilot Light 28 VAC 31601-07
Lamp Socket 31602-04
Lamp 250 Volt 31603-09
Oven Lamp Lens (Watch Glass) 31604-01
Oven Lamp Lens Gasket 31604-02
Circuit Board Temperature Control 40101-17
Circuit Board Buzzer 40102-10
Probe Pilot Flame Sensor 41100-07
Probe Temperature Sensor 41100-08
Turnbuckle Assembly 50312-02
Door Left Hand 51100-45
Door Right Hand 51100-46
Panel Label (Before F-90068) 60301-58
Panel Label, 2 Speed Fan (Before F-90068) 60301-73
Panel Label (After H-90069) 60301-102
Door Handle Assembly, Single Handle Oven 70603-15
Window Assembly 71301-04
Blower Wheel 71500-05
Bezel Control Board 72603-01
Bezel Fiber Spacer (Before H-90435) 20501-01
Bezel Screw, Short Qty. 1 (Before H-90435) 20102-19
Bezel Screw, Long Qty. 4 (Before H-90435) 20102-20
Bezel Washer (Before H-90435) 20201-13
Burner “U” Tube Steel 80002-05-1
Gas Manifold 80100-07
Pilot Burner Assembly 80201-14
Pilot Tube 60102-1381
Module Spark Ignitor NG (Before F-79932) 80300-04
Module Spark Ignitor LP (Before F-79932) 80300-05
Module Spark Ignitor NG & LP (After F-79933) 80300-08
Orifice Main Burner .0890 #43 DRL NG 80400-13
Orifice Main Burner .0595 #53 DRL LP 80400-14
Orifice Pilot Burner .010 DRL LP 80401-05
Orifice Pilot Burner .018 DRL NG 80401-10
Valve Combination Gas 24 VAC NG (Before F-87432) 60101-63
Valve Combination Gas Conversion Kit NG to LP (Before F-87432) 80505-07
Valve Combination Gas 24 VAC NG (After F-87433) 80505-10
Valve Combination Gas Conversion Kit NG to LP (After F-87433) 80505-11

30401-09

69

PARTS LIST GCCO-C

DESCRIPTION

Motor 1/3 HP 115/230 Volt with Momentary Switch (Before X-90068) 30200-15
Motor 1/3 HP 115 Volt 2 Speed (After V-90069) 30200-35
Switch Micro Convection Oven Door 30301-02
Switch Toggle On-Off 30303-06
Switch Toggle Spring Return 30303-16
Thermostat Safety 490°F Open (After G-70469)
Thermostat 450°F Oven
Terminal Block 24 Position Quick Disconnect 30503-01
Relay 24 VAC 30600-04
Contactor 2 Pole 24 VAC (Before X-90068) 30701-04
Contactor 2 Pole 30 Amp 24 VAC (After V-90069) 30701-05
Power Cord with Molded Plug 31107-02
Cable Ribbon Assembly (After G-70469) 31110-01
Transformer 115/24 VAC 31400-07
Transformer 115/12 VAC 31400-21
Lamp Socket 31602-04
Lamp Incandescent 250 Volt Clear 31603-09
Oven Lamp Lens (Watch Glass) 31604-01
Oven Lamp Lens Gasket 31604-02
Circuit Board Assembly Buzzer (After G-70469) 40102-10
Circuit Board Front Panel (After G-70469) 40102-20
Circuit Board Microprocessor (After G-70469) 40102-44
Circuit Board Upgrade Kit (Before G-70469) 60101-53
Probe Pilot Flame Sensor 41100-07
Probe Temperature Sensor 41100-08
Door Handle 11 1/2” Long Black “T” Style (Double Handle Ovens) 50800-12
Turnbuckle Assembly (Single Handle Ovens) 50312-02
Door Left Hand (Single Handle Ovens) 51100-45
Door Right Hand (Single Handle Ovens) 51100-46
Panel Label, Purple 60301-42
Valve Manual Main Water Supply (Steam Units) 70400-02
Valve Manual Water Supply (Steam Units) 70402-08
Valve Solenoid 24/60V Water Supply (Steam Units) 70403-01
Regulator Water Supply (Steam Units) 70404-01
Handle Assembly, Single Handle Oven 70603-15
Knob Thermostat 450°F Oven
Window Assembly, Oven Door 71301-04
Blower Wheel 71500-05
Blower Wheel (Steam Units) 51100-57
Orifice Water/Steam #60 DRL (Steam Units) 80405-01
Burner “U” Tube Steel 80002-05-1
Pilot Burner Assembly 80201-14
Pilot Tube 60102-1381
Module Spark Ignitor NG (Before G-70469) 80300-04
Module Spark Ignitor LP (Before G-70469) 80300-05
Module Spark Ingitor NG & LP (After G-70469) 80300-08
Orifice Main Burner .0890 #43 DRL NG 80400-13
Orifice Main Burner .0595 #53 DRL LP 80400-14
Orifice Pilot Burner .010 DRL LP 80401-05
Orifice Pilot Burner .018 DRL NG 80401-10
Valve Combination Gas 24 VAC NG (Before X-87440) 60101-63
Valve Combination Gas Conversion Kit NG to LP (Before X-87440) 80505-07
Valve Combination Gas 24 VAC NG (After X-87441) 80505-10
Valve Combination Gas Conversion Kit NG to LP (After X-87441) 80505-11

PART NO.

30401-09
30402-27

70701-17

70

PARTS LIST GCCO-PP

DESCRIPTION

Motor 1/3 HP 115 Volt 2 Speed 30200-35
Switch Micro Convection Oven Door 30301-02
Switch Toggle On-Off 30303-06
Switch Toggle Spring Return 30303-16
Thermostat Safety 490°F Open
Thermostat 450°F Oven
Terminal Block 24 Position Quick Disconnect 30503-01
Relay 24 VAC 30600-04
Contactor 2 Pole 24 VAC 30701-02
Contactor 2 Pole 30 Amp 24 VAC 30701-05
Power Cord with Molded Plug 31107-02
Cable Ribbon Assembly 31110-13
Transformer 115/24-12 VAC 31400-27
Lamp Socket 31602-04
Lamp Incandescent 250 Volt Clear 31603-09
Oven Lamp Lens (Watch Glass) 31604-01
Oven Lamp Lens Gasket 31604-02
Circuit Board Display 40102-24
Circuit Board Microprocessor 40102-26
Probe Pilot Flame Sensor 41100-07
Probe Temperature Sensor 41100-08
Oven Rack 50200-32
Oven Rack Slide 50200-59
Turnbuckle Assembly 50312-02
Door Left Hand 51100-45
Door Right Hand 51100-46
Panel Label, Purple Plus 60101-881
Valve Manual Main Water Supply (Steam Units) 70400-02
Valve Manual Water Supply (Steam Units) 70402-08
Valve Solenoid 24/60V Water Supply (Steam Units) 70403-01
Regulator Water Supply (Steam Units) 70404-01
Handle Assembly, Single Handle Oven 70603-15
Knob Thermostat 450°F Oven
Window Assembly, Oven Door 71301-04
Blower Wheel 71500-05
Blower Wheel (Steam Units) 51100-57
Orifice Water/Steam #60 DRL (Steam Units) 80405-01
Burner “U” Tube Steel 80002-05-1
Pilot Burner Assembly 80201-14
Pilot Tube 60102-1381
Module Spark Igniter NG & LP 80300-08
Orifice Main Burner .0890 #43 DRL NG 80400-13
Orifice Main Burner .0595 #53 DRL LP 80400-14
Orifice Pilot Burner .010 DRL LP 80401-05
Orifice Pilot Burner .018 DRL NG 80401-10
Valve Combination Gas 24 VAC NG 80505-10
Valve Combination Gas Conversion Kit NG to LP 80505-11
Wiring Harness, Motor GCCO-608
Wiring Harness, 120 Volt GCCO-609
Wiring Harness, 24 Volt GCCO-610

PART NO.

30401-09
30402-27

70701-17

71

PARTS LIST GCCO-PT

DESCRIPTION PART NO.

Motor 1/3 HP 115 Volt 2 Speed 30200-35
Switch Micro Convection Oven Door 30301-02
Switch Toggle On-Off 30303-06
Switch Toggle Spring Return 30303-16
Thermostat Safety 490°F Open
Thermostat 450°F Oven
Terminal Block 24 Position Quick Disconnect 30503-01
Relay 24 VAC 30600-04
Contactor 2 Pole 24 VAC 30701-02
Contactor 2 Pole 30 Amp 24 VAC 30701-05
Power Cord with Molded Plug 31107-02
Cable Ribbon Assembly 31110-13
Transformer 115/24-12 VAC 31400-27
Lamp Socket 31602-04
Lamp Incandescent 250 Volt Clear 31603-09
Oven Lamp Lens (Watch Glass) 31604-01
Oven Lamp Lens Gasket 31604-02
Circuit Board Display 40102-25
Circuit Board Microprocessor 40102-26
Probe Pilot Flame Sensor 41100-07
Probe Temperature Sensor 41100-08
Oven Rack 50200-21
Oven Rack Slide 50200-59
Turnbuckle Assembly 50312-02
Door Left Hand 51100-45
Door Right Hand 51100-46
Panel Label, Platinum 60101-882
Valve Manual Main Water Supply (Steam Units) 70400-02
Valve Manual Water Supply (Steam Units) 70402-08
Valve Solenoid 24/60V Water Supply (Steam Units) 70403-01
Regulator Water Supply (Steam Units) 70404-01
Handle Assembly, Single Handle Oven 70603-15
Knob Thermostat 450°F Oven
Window Assembly, Oven Door 71301-04
Blower Wheel 71500-05
Blower Wheel (Steam Units) 51100-57
Orifice Water/Steam #60 DRL (Steam Units) 80405-01
Burner “U” Tube Steel 80002-05-1
Pilot Burner Assembly 80201-14
Pilot Tube 60102-1381
Module Spark Ingitor NG & LP 80300-08
Orifice Main Burner .0890 #43 DRL NG 80400-13
Orifice Main Burner .0595 #53 DRL LP 80400-14
Orifice Pilot Burner .010 DRL LP 80401-05
Orifice Pilot Burner .018 DRL NG 80401-10
Valve Combination Gas 24 VAC NG 80505-10
Valve Combination Gas Conversion Kit NG to LP 80505-11
Wiring Harness, Motor GCCO-608
Wiring Harness, 120 Volt GCCO-609
Wiring Harness, 24 Volt GCCO-610

30401-09
30402-27

70701-17

72

THIS PAGE

INTENTIONALLY

LEFT BLANK

73