Vulcan VC66GD, VC44GC, VC66GC, VC6GD, VC44GD Service Manual

SERVICE MANUAL

VC4G & VC6G SERIES FULL SIZE
CONVECTION OVENS

VC4GS ML-126610
VC4GD ML-126611
VC4GC ML-136494
VC6GS ML-126612
VC6GD ML-126613
VC6GC ML-136495

- NOTICE -

This Manual is prepared for the use of trained Vulcan Service
Technicians and should not be used by those not properly
qualified.

This manual is not intended to be all encompassing. If you have
not attended a Vulcan Service School for this product, you should
read, in its entirety, the repair procedure you wish to perform to
determine if you have the necessary tools, instruments and skills
required to perform the procedure. Procedures for which you do
not have the necessary tools, instruments and skills should be
performed by a trained Vulcan Service Technician.

The reproduction, transfer, sale or other use of this Manual,
without the express written consent of Vulcan, is prohibited.

This manual has been provided to you by ITW Food Equipment
Group LLC ("ITW FEG") without charge and remains the property
of ITW FEG, and by accepting this manual you agree that you will
return it to ITW FEG promptly upon its request for such return at
any time in the future.

A product of Vulcan-Hart 3600 North Point Blvd Baltimore, MD 21222

F24682 Rev. F (1118)

VC4G & VC6G SERIES FULL SIZE CONVECTION OVENS

TABLE OF CONTENTS

SERVICE UPDATES ....................................................................................... 4

SERVICE UPDATES - VC4G / VC6G ................................................................... 4

GENERAL .................................................................................................. 5

INTRODUCTION ....................................................................................... 5

INSTALLATION ........................................................................................ 5

OPERATION ........................................................................................... 5

CLEANING ............................................................................................. 5

REFERENCE INFORMATION .......................................................................... 5

LUBRICATION ......................................................................................... 5

SPECIFICATIONS ...................................................................................... 5

TOOLS ................................................................................................. 6

REMOVAL AND REPLACEMENT OF PARTS ............................................................... 7

COVERS AND PANELS ................................................................................ 7

TOP FRONT COVER ............................................................................... 7

BOTTOM FRONT COVER .......................................................................... 7

CONTROL PANEL ................................................................................. 7

RIGHT SIDE PANEL ................................................................................ 7

CONTROL PANEL COMPONENTS ..................................................................... 8

COMPONENT PANEL COMPONENTS ................................................................. 9

TEMPERATURE PROBE (VC4GD/6GD) ............................................................... 10

GAS BURNER ........................................................................................ 11

GAS ORIFICE ......................................................................................... 12

GAS SOLENOID VALVE .............................................................................. 13

IGNITION CONTROL MODULE ....................................................................... 14

SPARK IGNITER AND FLAME SENSE ................................................................ 15

BLOWER AND MOTOR ENDING AT SERIAL NUMBER 481913935 .................................... 16

BLOWER AND MOTOR STARTING AT SERIAL NUMBER 481913936 ................................. 18

OVEN DOORS (SIMULTANEOUS DOORS) ENDING AT SERIAL NUMBER 481907145 ................ 19

ASSEMBLY REMOVAL ........................................................................... 19

DISASSEMBLY ................................................................................... 20

OVEN DOORS (SIMULTANEOUS DOORS) STARTING AT SERIAL NUMBER 481907146 .............. 20

OVEN DOORS AND BEARINGS (INDEPENDENT DOORS) ENDING AT SERIAL

NUMBER 481907145 .............................................................................. 21

DOOR CATCH BALL ASSEMBLY (INDEPENDENT DOORS) ........................................... 22

OVEN DOORS (INDEPENDENT DOORS) STARTING AT SERIAL NUMBER 481907146 ............... 22

ROLLER LATCH ASSEMBLY (INDEPENDENT DOORS) ............................................... 23

DOOR WINDOW ...................................................................................... 23

DOOR SWITCH ....................................................................................... 24

MECHANICAL KX THERMOSTAT (VC4GS/6GS) ...................................................... 24

HIGH LIMIT THERMOSTAT ........................................................................... 25

INTERIOR LIGHTS (REAR MOUNTED, ROUND) ...................................................... 25

INTERIOR LIGHTS (SIDE MOUNTED, SQUARE) ...................................................... 26

COOLING FAN ........................................................................................ 28

SERVICE PROCEDURES AND ADJUSTMENTS ........................................................... 29

SOLID STATE TEMPERATURE CONTROL CALIBRATION (VC4GD/6GD) ............................. 29

MECHANICAL THERMOSTAT CALIBRATION (VC4GS/6GS) .......................................... 31

SOLID STATE TEMPERATURE CONTROL TEST (VC4GD/6GD) ...................................... 32

TEMPERATURE PROBE TEST (VC4GD/6GD) ......................................................... 33

GAS PRESSURE ADJUSTMENT (UNITS UP TO FEBRUARY 2015) ................................... 33

GAS VALVE PRESSURE CHECK (UNITS AFTER FEBRUARY 2015) .................................. 35

VERIFICATION OF SPARK AT IGNITOR .............................................................. 36

DOOR SWITCH ADJUSTMENT ....................................................................... 36

BLOWER ADJUSTMENT .............................................................................. 37

DOOR ADJUSTMENT ................................................................................. 38

F24682 Rev. F (1118) Page 2 of 88

VC4G & VC6G SERIES FULL SIZE CONVECTION OVENS

DOOR STRIKE ADJUSTMENT (INDEPENDENT DOORS) ............................................. 39

DOOR CATCH BALL ADJUSTMENT (INDEPENDENT DOORS) ........................................ 39

DOOR CHAIN ADJUSTMENT (SIMULTANEOUS DOORS) ............................................. 41

INTRODUCTION .................................................................................. 41

PROCEDURE ..................................................................................... 41

COMPUTER CONTROL (VC4GC/VC6GC) ............................................................. 41

OPERATION ...................................................................................... 41

SETUP MODE .................................................................................... 42

PROBE TEST ..................................................................................... 42

SOLID STATE RELAY TEST ...................................................................... 42

COMPUTER CONTROL CALIBRATION (VC4GC/VC6GC) ............................................. 42

FLAME SENSE CURRENT TEST ...................................................................... 43

ELECTRICAL OPERATION ................................................................................ 46

COMPONENT FUNCTION ............................................................................ 46

COMPONENT LOCATION ............................................................................. 47

SEQUENCE OF OPERATION ......................................................................... 52

VC4GS, VC6GS WITH ROAST & HOLD OPTION (MECHANICAL KX THERMOSTAT) .............. 52

VC4GD, VC6GD WITH ROAST & HOLD OPTION (SOLID STATE

TEMPERATURE CONTROL) .................................................................. 57

VC4GC, VC6GC (ROAST & HOLD STANDARD ON COMPUTER MODEL) ......................... 62

COOL DOWN CYCLE (COMPUTER CONTROL MODEL) .......................................... 64

SCHEMATICS ............................................................................................ 65

VC4GS, VC6GS MECHANICAL (KX) CONTROLS ..................................................... 65

VC4GS, VC6GS MECHANICAL (KX) CONTROLS, ROAST & HOLD OPTION ........................... 66

VC4GD, VC6GD SOLID STATE TEMPERATURE CONTROL .......................................... 67

VC4GD, VC6GD SOLID STATE TEMPERATURE CONTROL, ROAST & HOLD OPTION ................ 69

VC4GC, VC6GC COMPUTER CONTROL (ROAST & HOLD STANDARD) .............................. 70

WIRING DIAGRAMS ...................................................................................... 72

VC4GS, VC6GS MECHANICAL (KX) CONTROLS ..................................................... 72

VC4GS, VC6GS MECHANICAL (KX) CONTROLS, ROAST & HOLD OPTION ........................... 74

VC4GD, VC6GD SOLID STATE TEMPERATURE CONTROL .......................................... 76

VC4GD, VC6GD SOLID STATE TEMPERATURE CONTROL, ROAST & HOLD OPTION ................ 79

VC4GC, VC6GC COMPUTER CONTROL (ROAST & HOLD STANDARD) .............................. 81

TROUBLESHOOTING ..................................................................................... 84

ALL MODELS ......................................................................................... 84

IGNITION MODULE DIAGNOSTICS ................................................................... 85

COMPUTER CONTROL MODELS ONLY .............................................................. 86

ERROR CODES .................................................................................. 87

© VULCAN 2018

Page 3 of 88 F24682 Rev. F (1118)

VC4G & VC6G SERIES FULL SIZE CONVECTION OVENS - SERVICE UPDATES

SERVICE UPDATES

SERVICE UPDATES - VC4G / VC6G

October 2018

Updated and Added Data Modules

• BLOWER AND MOTOR Starting at Serial
Number 481913936

• OVEN DOORS (SIMULTANEOUS DOORS)
Starting at Serial Number 481907146

• OVEN DOORS (INDEPENDENT DOORS)
Starting at Serial Number 481907146

• INTERIOR LIGHTS (Side Mounted, Square)

• INTERIOR LIGHTS (Rear Mounted, Round)

• DOOR ADJUSTMENT

• COMPONENT LOCATION

• FLAME SENSE CURRENT TEST

• VC4GS, VC6GS Mechanical (KX) Controls,
Roast & Hold Option

• VC4GD, VC6GD Solid State Temperature
Control

• VC4GC, VC6GC Computer Control (Roast &
Hold Standard)

• IGNITION MODULE DIAGNOSTICS

F24682 Rev. F (1118) Page 4 of 88

VC4G & VC6G SERIES FULL SIZE CONVECTION OVENS - GENERAL

GENERAL

INTRODUCTION

Procedures in this manual will apply to all models unless specified. Pictures and illustrations can be of any model
unless the picture or illustration needs to be model specific.

Models

FEATURES OPTIONS

COOK

MODEL

VC4GS 26.5" Mechanical (KX)

VC6GS 30.5" Mechanical (KX)

VC4GD 26.5" Solid State

VC6GD 30.5" Solid State

VC4GC 26.5" Computer

VC6GC 30.5" Computer

1

Simultaneous doors are optional (with or w/o window).

2

Stainless steel doors w/o window (standard).

3

Stainless steel doors with window (standard).

CAVITY

DEPTH

TEMPERTURE

CONTROL

DOORS

(50/50)

Independent 1

Independent 1

Independent 1

Independent 1

Independent 1

Independent 1

COOK

TIMER

2

1-Hour Dial 5-Hour Dial Optional Optional

2

1-Hour Dial 5-Hour Dial Optional Optional

3

1-Hour Dial 5-Hour Dial Optional Optional

3

1-Hour Dial 5-Hour Dial Optional Optional

24-Hour

3

Digital

24-Hour

3

Digital

TIMER

OR

HOLD

TIMER

Built in Built in Optional

Built in Built in Optional

COOK

BLOWER

&

208/240/60/1

HOLD

INSTALLATION

Refer to the Instructions Manual for detailed
installation instructions on single or stacked ovens.

OPERATION

Refer to the Instructions Manual for specific operating
instructions.

CLEANING

Refer to the Instructions Manual for specific cleaning
instructions.

Page 5 of 88 F24682 Rev. F (1118)

REFERENCE INFORMATION

Refer to the Parts Catalog F43031 for parts
information.

LUBRICATION

• Cavity blower motor has sealed bearings and
requires no additional lubrication.

• Huskey™ TF-1000 grease or equivalent high
temperature Teflon grease.

SPECIFICATIONS

Electrical

Voltage - 120/60/1

Amps - 8.0 Amps

VC4G & VC6G SERIES FULL SIZE CONVECTION OVENS - GENERAL

Input BTU Rating

Natural Gas - 44,000 BTU input at 3.5 in. W.C.

Units after Serial Number Break (VC4GD 481835388,
VC6GD 481835406, VC4GD 541077665) Natural
Gas - 50,000 BTU input at 5.0 in. W.C.

Propane Gas - 44,000 BTU input at 10.0 in. W.C.

Units after Serial Number Break (VC4GD 481835394
& 541077965, VC6GD 481835429) Propane Gas ­50,000 BTU input at 10.0 in. W.C.

Gas Line Pressures

Natural - Recommend (in. W.C.) 7.0, Min 5.0

Natural - Recommend (in W.C.) 8.0, Min 6.0 for Units
after Serial Number Break (VC4GD 481835388,
VC6GD 481835406, VC4GD 541077665)

Propane - Recommend (in. W.C.) 11.0, Min 11.0 (All
Propane Units)

Maximum 14.0 in. W.C. (Nat. or Prop.)

TOOLS

Standard

• Standard set of hand tools

• VOM with ability to measure micro amp current

VOM with minimum of NFPA-70E CAT III 600V,
UL/CSA/TUV listed. Sensitivity of at least 20,000
ohms per volt. Meter leads must also be rated at
CAT III 600V.

• Gear Puller to remove blower

Special

• Temperature tester (thermocouple type)

• Manometer

F24682 Rev. F (1118) Page 6 of 88

VC4G & VC6G SERIES FULL SIZE CONVECTION OVENS - REMOVAL AND REPLACEMENT OF PARTS

REMOVAL AND REPLACEMENT OF PARTS

COVERS AND PANELS

Disconnect the electrical power to
the machine and follow lockout /
tagout procedures.

SHUT OFF THE GAS BEFORE SERVICING THE
UNIT.

Top Front Cover

1. The top front cover is secured with four (4)
screws, two on each side of cover. Remove these
screws then remove the cover from the oven.

Control Panel

1. Remove three (3) screws on the right side which
secure the control panel then pull the panel away
from the oven.

Fig. 3

NOTE: If the oven has a mechanical (KX type)

thermostat, it must be removed from the control panel
first, before removing the control panel.

2. Disconnect the temperature probe leads from the
solid state temperature control.

Fig. 1

2. Reverse the procedure to install.

Bottom Front Cover

1. The bottom front cover is secured with four (4)
screws, two on each side of cover. Remove these
screws then remove the cover from the oven.

Fig. 2

2. Reverse the procedure to install.

3. Unplug the wire harness connector to the control
panel components.

4. Reverse the procedure to install.

Right Side Panel

1. Remove the screws which secure the right side
of the top front cover, bottom front cover and
control panel.

2. Remove the remaining six screws securing the
right side panel.

Fig. 4

Page 7 of 88 F24682 Rev. F (1118)

VC4G & VC6G SERIES FULL SIZE CONVECTION OVENS - REMOVAL AND REPLACEMENT OF PARTS

3. Pull the right side panel out at the bottom then
down to remove.

4. Reverse the procedure to install.

CONTROL PANEL COMPONENTS

Disconnect the electrical power to
the machine and follow lockout /
tagout procedures.

Removable Components Procedure

1. Remove the Control Panel.

2. Remove the component being replaced.

3. Reverse the procedure to install the replacement
component, then check oven for proper
operation.

Fig. 5

Fig. 6

F24682 Rev. F (1118) Page 8 of 88

VC4G & VC6G SERIES FULL SIZE CONVECTION OVENS - REMOVAL AND REPLACEMENT OF PARTS

Fig. 7

COMPONENT PANEL

COMPONENTS

Disconnect the electrical power to
the machine and follow lockout /
tagout procedures.

Removable Components Procedure

1. Remove the Right Side Panel.

NOTE: If right side panel is not accessible, this
component can be serviced by removing the Control
Panel.

2. Disconnect the wire leads to the component
being replaced.

3. Remove the component.

4. Reverse the procedure to install the replacement
component and check oven for proper operation.

Fig. 8

Page 9 of 88 F24682 Rev. F (1118)

VC4G & VC6G SERIES FULL SIZE CONVECTION OVENS - REMOVAL AND REPLACEMENT OF PARTS

Fig. 9

Fig. 10

TEMPERATURE PROBE (VC4GD/

6GD)

Disconnect the electrical power to
the machine and follow lockout /
tagout procedures.

1. Remove the Right Side Panel.

NOTE: If right side panel is not accessible, this
component can be serviced by removing the Control
Panel.

2. Disconnect the probe leads from the solid state
temperature control.

3. Remove the racks and right rack support.

4. Remove the probe guard.

1st Generation Production Guard Shown

F24682 Rev. F (1118) Page 10 of 88

VC4G & VC6G SERIES FULL SIZE CONVECTION OVENS - REMOVAL AND REPLACEMENT OF PARTS

GAS BURNER

Disconnect the electrical power to
the machine and follow lockout /

Fig. 11

5. Remove probe by pushing it through the oven
wall and into the control panel area.

SHUT OFF THE GAS BEFORE SERVICING THE
UNIT.

1. Remove the BOTTOM FRONT COVER.

2. Disconnect the ignition cable and the flame
sense lead wire.

tagout procedures.

Fig. 12

NOTE: The hole in the oven cavity wall does not line

up straight with the oven cavity outer shell, therefore
the probe must be removed at an angle.

6. Reverse the procedure to install the replacement
probe.

When installing a 2nd generation guard, the tip of the
probe should be located near the center of the large
cutout, as shown in Fig. 13. The end with the wire
attached should be protected by the guard. It is
possible to damage the probe/wire with force from a
tray if probe is not protected properly.

Fig. 13

Fig. 14

3. Remove the bolts securing the gas manifold to
the oven and place the manifold to the side.

Fig. 15

4. Remove the screws securing the burner cover
then lift out.

7. Adjust the temperature control as outlined under
SOLID STATE TEMPERATURE CONTROL
CALIBRATION (VC4GD/6GD).

Page 11 of 88 F24682 Rev. F (1118)

VC4G & VC6G SERIES FULL SIZE CONVECTION OVENS - REMOVAL AND REPLACEMENT OF PARTS

GAS ORIFICE

Disconnect the electrical power to
the machine and follow lockout /
tagout procedures.

Fig. 16

5. Grasp the burner and lift out.

Fig. 17

6. Reverse procedure to install the replacement
burner.

NOTE: Ensure that burner positioning bracket (U
shaped end) is inserted into slot at the rear of the
burner chamber.

SHUT OFF THE GAS BEFORE SERVICING THE
UNIT.

1. Remove the Bottom Front Cover.

2. Remove the bolts securing the gas manifold to
the oven and place the manifold to the side.

Fig. 19

3. Remove the gas orifice from the spud on the
manifold and replace with the correct orifice for
the given altitude.

NOTE: When installing current production burner
covers:

• Lay cover flat over burner with openings
aligned behind ignitor.

• Push burner into unit and flip cover 90° up
and align mounting holes.

4. Reverse procedure to install and check for proper

CURRENT PRODUCTION UNIT SHOWN

7. Check for proper operation.

F24682 Rev. F (1118) Page 12 of 88

Fig. 20

operation.

VC4G & VC6G SERIES FULL SIZE CONVECTION OVENS - REMOVAL AND REPLACEMENT OF PARTS

GAS SOLENOID VALVE

Disconnect the electrical power to
the machine and follow lockout /
tagout procedures.

SHUT OFF THE GAS BEFORE SERVICING THE
UNIT.

1. Remove the CONTROL PANEL and the RIGHT
SIDE PANEL.

NOTE: if right side panel is not accessible, this
component can be serviced by removing the
CONTROL PANEL.

2. Disconnect the lead wires.

3. Disconnect the compression fittings to the valve.

SECOND GENERATION UNIT SHOWN (After April

2005 thru February 2015)

FIRST GENERATION UNIT SHOWN (Before April

2005)

Page 13 of 88 F24682 Rev. F (1118)

CURRENT PRODUCTION SHOWN (After February

2015)

4. Loosen the bolts securing the valve and bracket
assembly then remove the screws securing the
valve to the bracket.

VC4G & VC6G SERIES FULL SIZE CONVECTION OVENS - REMOVAL AND REPLACEMENT OF PARTS

CURRENT PRODUCTION SHOWN (After February

2015)

FIRST GENERATION UNIT SHOWN (Before April

2005)

SECOND GENERATION UNIT SHOWN (After April

2005 thru February 2015)

5. Reverse the procedure to install the replacement
gas valve.

NOTE: Clean the pipe threads and apply pipe joint
compound to threads. Any pipe joint compound used,
must be resistant to the action of propane gases.

All gas joints disturbed during servicing must be
checked for leaks. Check with a soap and water
solution (bubbles). Do not use an open flame.

6. Verify gas pressure as outlined under GAS
PRESSURE ADJUSTMENT (for units before
February 2015) and GAS VALVE PRESSURE
CHECK (for units after February 2015) and check
for proper operation.

IGNITION CONTROL MODULE

Disconnect the electrical power to
the machine and follow lockout /
tagout procedures.

SHUT OFF THE GAS BEFORE SERVICING THE
UNIT.

1. Remove the Right Side Panel.

NOTE: If right side panel is not accessible, this
component can be serviced by removing the Control
Panel.

F24682 Rev. F (1118) Page 14 of 88

VC4G & VC6G SERIES FULL SIZE CONVECTION OVENS - REMOVAL AND REPLACEMENT OF PARTS

2. Loosen the screws securing the mounting
bracket to the component panel and remove the
bracket.

Fig. 27

NOTE: When replacing ignition cable, order service

kit which includes ignition cable and insulation cap for
the coil.

SPARK IGNITER AND FLAME

SENSE

Disconnect the electrical power to
the machine and follow lockout /
tagout procedures.

SHUT OFF THE GAS BEFORE SERVICING THE
UNIT.

1. Remove the gas burner as outlined under GAS
BURNER.

2. Remove the screws securing the ignitor and
flame sense to burner then remove the
assembly.

3. Disconnect the lead wires and igniter cable from
the ignition module board.

Fig. 28

4. Remove the ignition module board from the
mounting bracket.

5. Reverse the procedure to install the replacement
ignition module board.

Fig. 29

3. Reverse the procedure to install the assembly
and check for proper operation.

NOTE: Check to ensure the spark gap distance is
approximately 1/8". If the gap appears to be excessive
or poor sparking is occurring then adjust.

PREVOUS PRODUCTION SHOWN

Page 15 of 88 F24682 Rev. F (1118)

VC4G & VC6G SERIES FULL SIZE CONVECTION OVENS - REMOVAL AND REPLACEMENT OF PARTS

CURRENT PRODUCTION SHOWN

BLOWER AND MOTOR Ending at

Serial Number 481913935

Disconnect the electrical power to
the machine and follow lockout /
tagout procedures.

Fig. 33

SHUT OFF THE GAS BEFORE SERVICING THE
UNIT.

1. Take out the racks and rack supports.

2. Remove screws securing the “snorkel” and
remove the snorkel.

4. If replacing:

A. Blower Only - Loosen set screws on blower

hub and using a bearing puller, remove
blower from motor shaft.

1) Reverse procedure to install and adjust
blower position as outlined under
BLOWER ADJUSTMENT.

B. Motor - perform step 4A and continue

procedure.

5. Remove the screws securing the air baffle to the
rear wall at the lower right hand corner.

Fig. 32

3. Remove screws securing baffle panel and
remove the panel.

6. Remove the nuts that secure the motor mounting

F24682 Rev. F (1118) Page 16 of 88

Fig. 34

plate to the rear wall.

VC4G & VC6G SERIES FULL SIZE CONVECTION OVENS - REMOVAL AND REPLACEMENT OF PARTS

Fig. 35

7. Place a piece of cardboard on the bottom of the
oven cavity to protect its surface from any
damage during motor assembly removal.

8. Pull the motor assembly into the oven cavity and
place it on the cardboard.

9. Remove the junction box cover from the motor,
disconnect lead wires and remove the conduit.

10. Remove motor mounting bolts and flat washers
then lift the motor from the mounting plate.

11. Position the replacement motor on the motor
mounting plate and install mounting bolts and
washers. Hand tighten mounting bolts only.

12. Reconnect lead wires at the motor, replace
conduit and junction box cover.

NOTE: Check data plate on motor for wiring
schematic. The motor must rotate clockwise when
viewed from the shaft end.

13. Slide blower onto motor shaft until hub is flush
with end of shaft then tighten set screws.

14. Adjust motor position until blower is parallel to
motor mounting plate as outlined under
BLOWER ADJUSTMENT.

15. Position motor mounting plate on the rear wall
and secure with nuts and washers.

16. Replace the baffle panel and “snorkel”.

17. Replace the air baffle on the rear wall at the lower
right hand corner.

18. Remove cardboard from the bottom of the oven
cavity.

19. Install rack guides and racks.

20. Check oven for proper operation.

Fig. 36

Page 17 of 88 F24682 Rev. F (1118)

VC4G & VC6G SERIES FULL SIZE CONVECTION OVENS - REMOVAL AND REPLACEMENT OF PARTS

BLOWER AND MOTOR Starting at

Serial Number 481913936

Disconnect the electrical power to
the machine and follow lockout /
tagout procedures.

Shut off the gas before servicing the
unit and follow lockout / tagout
procedures.

1. Remove RIGHT SIDE PANEL(S).

2. Disconnect motor harness (1, Fig. 37).

4. Push motor wiring harness/cord out hole in rear
panel.

5. Remove racks.

Fig. 38

6. Remove screws securing "snorkel" and remove
snorkel.

Fig. 39

7. Remove blower baffle screws (2, Fig. 40) if
applicable.

Fig. 37

3. Pinch cord grip together to remove from rear
panel.

F24682 Rev. F (1118) Page 18 of 88

VC4G & VC6G SERIES FULL SIZE CONVECTION OVENS - REMOVAL AND REPLACEMENT OF PARTS

Fig. 42

13. Reverse procedure to install.

14. Verify operation.

Fig. 40

8. Remove motor mounting plate nuts (1, Fig. 40).

9. Place a piece of cardboard on bottom of oven
cavity to protect its surface from any damage
during motor assembly removal.

10. Pull motor assembly into oven cavity and place
on cardboard.

11. Remove motor mounting bolts and washers and
lift motor off mounting plate.

OVEN DOORS (SIMULTANEOUS

DOORS) Ending at Serial Number

481907145

Disconnect the electrical power to
the machine and follow lockout /
tagout procedures.

Assembly Removal

1. Remove the Top Front Cover and Bottom Front
Cover.

2. Remove the door switch lever.

Fig. 41

NOTE: Motor graphics are shown with motor

installed.

12. Remove drip pan from motor and install onto
replacement motor.

Fig. 43

3. Remove the top bearing retainers and top
bearings.

Page 19 of 88 F24682 Rev. F (1118)

VC4G & VC6G SERIES FULL SIZE CONVECTION OVENS - REMOVAL AND REPLACEMENT OF PARTS

Fig. 44

4. Remove the lower door seal strip to expose the
mounting screws of the door assembly.

A. Remove the two (2) lower sill bolts by the

lower door shaft and the four (4) counter­sunk screws from the lower sill.

A. Door assembly parts are now accessible for

inspection and/or replacement if necessary.

Fig. 46

Fig. 45

NOTE: The door assembly is heavy and will drop

down once the last screw is removed. If removing door
assembly with-out assistance, use caution.

5. Lift up on the door assembly and swing the right
side out then move the assembly to the left to
clear the slots in the upper door sill.

6. Lay the door assembly on a flat cushioned
surface for disassembly.

7. Reverse procedure to install door assembly and
check for proper adjustment as outlined under
DOOR ADJUSTMENT , DOOR CHAIN
ADJUSTMENT (SIMULTANEOUS DOORS) and
DOOR SWITCH ADJUSTMENT.

Disassembly

1. Remove the door assembly as outlined in
"ASSEMBLY REMOVAL".

2. Remove the door chain by loosening one of the
turnbuckles.

3. Loosen the set screw on the sprocket of door
being replaced.

6. Reverse procedure to re-assemble the door
assembly parts and check for proper adjustment
as outlined under DOOR CHAIN ADJUSTMENT
(SIMULTANEOUS DOORS).

OVEN DOORS (SIMULTANEOUS

DOORS) Starting at Serial Number

481907146

1. Remove TOP FRONT COVER and BOTTOM
FRONT COVER.

2. Remove door switch lever.

Fig. 47

3. Remove door chain by loosening one of the
turnbuckles (Fig. 48).

4. Drive out the Spirol pin from the sprocket of door
being replaced.

5. Remove the door from lower sill bearings and
sprocket.

F24682 Rev. F (1118) Page 20 of 88

VC4G & VC6G SERIES FULL SIZE CONVECTION OVENS - REMOVAL AND REPLACEMENT OF PARTS

9. Perform door adjustments.

A. DOOR ADJUSTMENT .

B. DOOR CHAIN ADJUSTMENT

(SIMULTANEOUS DOORS) .

C. DOOR SWITCH ADJUSTMENT .

OVEN DOORS AND BEARINGS

(INDEPENDENT DOORS) Ending at

Serial Number 481907145

Disconnect the electrical power to
the machine and follow lockout /

Fig. 48

4. Loosen the set screw on the sprocket of door
being replaced (Fig. 48).

5. Drive out the spiral pin from the sprocket of door
being replaced (

Fig. 48).

1. Remove the Top Front Cover and Bottom Front
Cover.

2. Remove the door switch lever.

tagout procedures.

6. While supporting door, remove hex head bolts
holding upper bearing retainer (1, Fig. 49) and
upper shaft bracket (2, Fig. 49).

Fig. 49

7. Remove door(s) from lower sill bearings and
sprocket Fig. 48.

Fig. 50

3. Remove the lower door seal strip to expose the
mounting screws of the door assembly.

4. Remove the two (2) lower sill bolts by the lower
door shaft and the four (4) counter-sunk screws
from the lower sill.

Fig. 51

Lay door on flat protective surface to service.

8. Reverse procedure to install.

Verify spacers are reassembled as found when
removed.

NOTE: The door assembly is heavy and will drop
down once the last screw is removed. If removing door
assembly with-out assistance, the ignition cable,
flame sense lead and gas manifold should also be
removed to avoid damage to these components.

Page 21 of 88 F24682 Rev. F (1118)

VC4G & VC6G SERIES FULL SIZE CONVECTION OVENS - REMOVAL AND REPLACEMENT OF PARTS

5. Tilt the top of the door slightly forward and lift the
door up until the bottom of the door shaft clears
the opening in the sill.

6. Lay the door flat to prevent damage.

7. The top and bottom bearings are now accessible
for inspection and/or replacement if needed.

A. If bearings are OK, proceed to step 8.

B. If replacing the top bearing, remove the top

bearing retainer and top bearing.

Fig. 53

3. Reverse procedure to install.

Fig. 52

C. If replacing the bottom bearing, remove it

from the door shaft or the lower sill opening.

8. Reverse procedure to install door assembly and
check for proper adjustment as outlined under
DOOR ADJUSTMENT and DOOR SWITCH
ADJUSTMENT.

DOOR CATCH BALL ASSEMBLY

(INDEPENDENT DOORS)

NOTE: For units with serial number starting with 48

made before 8/13/07 and serial number starting with
54 made before 8/27/07.

Disconnect the electrical power to
the machine and follow lockout /
tagout procedures.

4. Adjust the ball catch as outlined under
CATCH BALL ADJUSTMENT (INDEPENDENT
DOORS).

DOOR

OVEN DOORS (INDEPENDENT

DOORS) Starting at Serial Number

481907146

Disconnect the electrical power to
the machine and follow lockout /
tagout procedures.

1. Remove TOP FRONT COVER.

2. If servicing right side door, remove door switch
lever (1, Fig. 54).

1. Remove the FRONT COVER.

2. Remove the screws that secure the door catch
assembly.

3. While supporting door, remove hex bolts holding

F24682 Rev. F (1118) Page 22 of 88

Fig. 54

upper bearing retainer (1, Fig. 55 ) and upper
shaft bracket (2, Fig. 55).

VC4G & VC6G SERIES FULL SIZE CONVECTION OVENS - REMOVAL AND REPLACEMENT OF PARTS

Fig. 56

2. Reverse procedure to install.

Fig. 55

4. Lift door off lower shaft bracket.

Lay door on flat protective surface to service.

5. Reverse procedure to install.

6. Perform door switch adjustment if servicing right
side door.

ROLLER LATCH ASSEMBLY

(INDEPENDENT DOORS)

NOTE: For units with serial number starting with 48

made after 8/12/07 and serial number starting with 54
made after 8/26/07.

Disconnect the electrical power to
the machine and follow lockout /
tagout procedures.

1. Remove the screws that attach roller latch
assembly to door.

DOOR WINDOW

Disconnect the electrical power to
the machine and follow lockout /
tagout procedures.

1. Remove the screws at the top and bottom of
door.

Fig. 57

2. Independent doors:

A. Remove the door handle then remove the

outer door panel.

B. Lift out the inner door panel and window

assembly.

NOTE: Left door only - remove door seal from the
inside edge of the door.

3. Simultaneous doors:

A. If replacing window on the left door, remove

the handle from the front of the door then
remove door seal from the inside edge of the
door.

Page 23 of 88 F24682 Rev. F (1118)

VC4G & VC6G SERIES FULL SIZE CONVECTION OVENS - REMOVAL AND REPLACEMENT OF PARTS

1) Lift out the inner door panel and
window assembly.

2) If replacing window on the right door,
remove the screws along the inside
edge (if applicable) of the door then
remove the inner door panel and
window assembly.

4. Remove the screws securing the window “tabs”
to the door bracket and lift the window assembly
out from the door frame.

3. Remove the switch.

Fig. 59

4. Reverse procedure to install the replacement
switch and check for proper adjustment as
outlined under DOOR SWITCH ADJUSTMENT.

MECHANICAL KX THERMOSTAT

(VC4GS/6GS)

Fig. 58

5. Reverse procedure to install the replacement
window.

DOOR SWITCH

Disconnect the electrical power to
the machine and follow lockout /
tagout procedures.

Disconnect the electrical power to
the machine and follow lockout /
tagout procedures.

1. Remove the racks and right rack support.

2. Remove the thermostat knob and mounting
screws from the control panel and then remove
the control panel.

3. Remove the probe guard from the oven cavity
wall.

NOTE: When installing, the probe should not extend
beyond the probe guard.

4. Remove the thermostat bulb from the oven cavity
by pushing it through the oven wall and into the
control panel area.

NOTE: The hole in the oven cavity wall does not line
up straight with the oven cavity outer shell, therefore
the probe must be removed at an angle.

5. Reverse the procedure to install.

6. Adjust the thermostat as outlined under
MECHANICAL THERMOSTAT CALIBRATION
(VC4GS/6GS).

1. Remove the Top Front Cover.

2. Disconnect the lead wires to the door switch.

F24682 Rev. F (1118) Page 24 of 88

VC4G & VC6G SERIES FULL SIZE CONVECTION OVENS - REMOVAL AND REPLACEMENT OF PARTS

HIGH LIMIT THERMOSTAT

Disconnect the electrical power to
the machine and follow lockout /
tagout procedures.

1. Take out racks from the oven.

2. Remove the high limit thermostat cover/mounting
plate from inside the oven cavity at the top.

INTERIOR LIGHTS (Rear Mounted,

Round)

Disconnect the electrical power to
the machine and follow lockout /
tagout procedures.

Lamp

1. Remove racks.

2. Unscrew glass lens for the light being replaced
then unscrew bulb.

NOTE: Use a cloth when handling bulb so you do not
leave fingerprints on bulb.

Fig. 60

3. Disconnect lead wires from high limit thermostat
then remove high limit thermostat from cover/
mounting plate.

Fig. 61

NOTE: Remove the old RTV from the cover and

mating surfaces inside the oven cavity and apply new
RTV before installing.

Fig. 62

3. Replace bulb then reverse procedure to install.

Disconnect the electrical power to
the machine and follow lockout /
tagout procedures.

Lamp Assembly

1. Remove lens and bulb.

2. Remove springs from retaining tabs (2 places) on
the socket.

4. Reverse procedure to install.

Page 25 of 88 F24682 Rev. F (1118)

VC4G & VC6G SERIES FULL SIZE CONVECTION OVENS - REMOVAL AND REPLACEMENT OF PARTS

Fig. 63

3. Depress retaining tabs and pull socket out from
the oven, far enough to disconnect lead wires.

4. Remove socket from the oven.

5. Attach lead wires to the replacement socket.

6. Insert socket into the hole in oven and push until
socket is held in place by retaining tabs.

7. Install light bulb and lens.

8. Check for proper operation.

INTERIOR LIGHTS (Side Mounted,

Square)

Bulb Replacement

Disconnect the electrical power to
the machine and follow lockout /
tagout procedures.

1. Remove racks and right-side hand rack guide.

2. Pull lamp cover off.

3. Grasp lamp using a clean cloth and remove from
lamp assembly.

Fig. 64

4. Reverse procedure to install new bulb.

NOTE: Verify gasket (1, Fig. 65) is flat on lamp cover
and not damaged.

Lamp Assembly Replacement

F24682 Rev. F (1118) Page 26 of 88

Fig. 65

VC4G & VC6G SERIES FULL SIZE CONVECTION OVENS - REMOVAL AND REPLACEMENT OF PARTS

Disconnect the electrical power to
the machine and follow lockout /
tagout procedures.

1. Remove racks.

2. Remove BULB if reusing.

3. Lift right side rack guide off oven cavity.

4. Pull lamp cover off from the top or bottom.

5. Insert narrow blade screwdriver into tab and
bend out to release. Repeat with second tab.

Fig. 66

6. Pull lamp housing out of oven cavity.

7. Disconnect wires.

Fig. 67

8. Reverse procedure to install.

NOTE: Verify gasket (1, Fig. 68) is flat on lamp cover
and not damaged.

Fig. 68

Page 27 of 88 F24682 Rev. F (1118)

VC4G & VC6G SERIES FULL SIZE CONVECTION OVENS - REMOVAL AND REPLACEMENT OF PARTS

COOLING FAN

Disconnect the electrical power to
the machine and follow lockout /
tagout procedures.

1. Remove the Right Side Panel.

NOTE: If right side panel is not accessible, this
component can be serviced by removing the Control
Panel.

Disconnect the lead wires to the fan motor by
removing wire nuts.

2. Remove the screws securing the air deflector to
the fan then loosen the tab screw holding the fan
to the component panel. Rotate the tab so that
the fan will clear and remove the fan.

Fig. 69

3. Reverse the procedure to install the replacement
fan and check for proper operation.

NOTE: The fan must be installed so air is pulled from
the rear of the oven and blown into the control area.
The arrow on the fan body indicates “air flow” direction
and should be pointing toward the controls.

NOTE: Ensure fan is seated “squarely” against the air
tube and the oven bottom.

NOTE: The air deflector should be angled upwards
at approximately 30 degrees to properly direct the air
flow.

F24682 Rev. F (1118) Page 28 of 88

VC4G & VC6G SERIES FULL SIZE CONVECTION OVENS - SERVICE PROCEDURES AND ADJUSTMENTS

SERVICE PROCEDURES AND ADJUSTMENTS

Certain procedures in this section require electrical test or measurements while power is
applied to the machine. Exercise extreme caution at all times and follow Arc Flash procedures.
If test points are not easily accessible, disconnect power and follow Lockout/Tagout
procedures, attach test equipment and reapply power to test.

SOLID STATE TEMPERATURE

CONTROL CALIBRATION (VC4GD/

6GD)

UNITS BEFORE JUNE 2013

1. Place a thermocouple in geometric center of
oven cavity.

2. Set ON-OFF-COOL DOWN switch to ON.

3. Set temperature control dial to 350°F.

4. Allow oven temperature to stabilize (normally 3
cycles).

5. Record temperature at which Heat lamp goes
OFF and comes ON for at least two complete
heating cycles.

6. Calculate differential by subtracting temperature
indicated when lamp goes out from temperature
indicated when lamp comes on.

Differential = Heat lamp OFF - Heat lamp ON

Example: 360° (lamp off) - 340° (lamp on) =
20°

A. Calculated differential should be less than

20°F.

1) If differential is less than 20°F,
temperature control circuit is
functioning properly.

7. Calculate average temperature by adding
temperature indicated when lamp goes out to
temperature indicated when lamp comes on and
dividing this answer by 2.

[Temp. (lamp off) + Temp. (lamp on)] ÷ 2 =
Average Temp. Example: (360° + 340°) ÷ 2 =
350°

A. If average temperature is less than 10°F

from dial setting, thermostat is properly
calibrated.

B. If average temperature is more than 10°F

from dial setting, thermostat calibration
must be adjusted.

1) Loosen temperature control knob set
screw and remove knob from stem.

2) Loosen temperature control mounting
screws only enough to rotate control.

a. Place thumb and forefinger on

mounting screw heads, apply
pressure and slightly rotate screw
heads (body of control) in slot.
Rotate clockwise to increase
temperature and
counterclockwise to decrease.

b. Center stem in the opening and

re-tighten temperature control
mounting screws.

a. Proceed to

2) If differential is more than 20°F:

a. Check temperature probe as

outlined under TEMPERATURE
PROBE TEST (VC4GD/6GD).

b. If probe is functioning properly

then temperature control is
malfunctioning.

a) Install a replacement

Step 7.

temperature control and
check calibration.

Page 29 of 88 F24682 Rev. F (1118)

VC4G & VC6G SERIES FULL SIZE CONVECTION OVENS - SERVICE PROCEDURES AND ADJUSTMENTS

6. Calculate differential by subtracting temperature
indicated when lamp goes out from temperature
indicated when lamp comes on.

Differential = Heat lamp OFF - Heat lamp ON

Example: 360° (lamp off) - 340° (lamp on) =
20°

A. Calculated differential should be less than

20°F.

1) If differential is less than 20°F,
temperature control circuit is
functioning properly.

a. Proceed to Step 7.

2) If the differential is more than 20°F:

a. Check the temperature probe as

outlined under TEMPERATURE
PROBE TEST (VC4GD/6GD).

b. If probe is functioning properly

c. Replace knob and re-tighten set

screw.

d. Rotate knob to lowest

temperature setting then back to
350°F.

e. Repeat average temperature

calculation in Step 7.

NOTE: Allow oven to cycle at least two times between
adjustments before performing calculation.

a) If average temperature still

differs more than 10°F from
dial setting, adjust
thermostat calibration until
average temperature is
within tolerance.

C. If above adjustment cannot be obtained,

replace temperature control and check
calibration.

UNITS AFTER JUNE 2013

1. Place a thermocouple in geometric center of
oven cavity.

2. Set ON-OFF-COOL DOWN switch to ON.

3. Set temperature control dial to 350°F.

4. Allow oven temperature to stabilize (normally 3
cycles).

7. Calculate average temperature by adding
temperature indicated when lamp goes out to
temperature indicated when lamp comes on and
dividing this answer by 2.

[Temp. (lamp off) + Temp. (lamp on)] ÷ 2 =
Average Temp. Example: (360° + 340°) ÷ 2 =
350°

A. If average temperature is less than 10°F

from dial setting, thermostat is properly
calibrated.

B. If average temperature is more than 10°F

from dial setting, thermostat calibration
must be adjusted.

1) Loosen temperature control knob set

2) Access adjustment potentiometer

NOTE: If no access hole exists in overlay, you may
carefully create one.

then temperature control is
malfunctioning.

a) Install a replacement

temperature control and
check calibration.

screw and remove knob from stem.

located at 3 o'clock position.

5. Record temperature at which Heat lamp goes
OFF and comes ON for at least two complete
heating cycles.

F24682 Rev. F (1118) Page 30 of 88

VC4G & VC6G SERIES FULL SIZE CONVECTION OVENS - SERVICE PROCEDURES AND ADJUSTMENTS

6. Calculate the differential by subtracting the
temperature indicated when heat lamp goes out
from temperature indicated when heat lamp
comes on.

Differential = Heat lamp OFF - Heat lamp ON

Example: 360° (lamp off) - 340° (lamp on) 20°

A. The differential calculated should be less

than 30°F.

1) If the differential is less than 30°F, the
thermostat is functioning properly.

a. Proceed to Step 7.

2) If the differential is more than 30°F, the
thermostat is malfunctioning.

a. Install a replacement thermostat

and check calibration.

a. Turn clockwise to increase,

counterclockwise to decrease
temperature

b. Repeat average temperature

calculation in Step 7.

NOTE: Allow oven to cycle at least two times between
adjustments before performing calculation.

a) If average temperature still

differs more than 10°F from
dial setting, adjust
thermostat calibration until
average temperature is
within tolerance.

C. If above adjustment cannot be obtained,

replace temperature control and check
calibration.

MECHANICAL THERMOSTAT

CALIBRATION (VC4GS/6GS)

1. Place a thermocouple in the geometric center of
the oven cavity.

2. Set the ON-OFF-COOL DOWN switch to ON.

3. Set the thermostat dial to 350°F.

4. Allow the oven temperature to stabilize (normally
3 cycles).

5. Record the temperature when the thermostat
cycles OFF and ON for at least three complete
cycles.

7. Calculate the average temperature by adding the
temperature indicated when the heat lamp goes
out to the temperature indicated when the heat
lamp comes on and dividing this answer by 2.

[Temp. (lamp off) +Temp. (lamp on)] ÷ 2 =
Average Temp.

Example: 360° 340° ÷ 2 350°

A. If the average temperature is less than 15°F

from the dial setting, the thermostat is
properly calibrated.

B. If the average temperature is more than

15°F of the dial setting, the thermostat
calibration must be adjusted.

1) Remove the thermostat knob.

2) Hold the thermostat shaft and turn the
inner set screw clockwise to decrease
temperature or counterclockwise to
increase temperature (¼ turn = 35°(F).

8. Replace the knob and repeat Step 7 until the
average temperature is within tolerance.

NOTE: Allow the oven to cycle at least two times
between adjustments before performing the
calculation.

9. If the above adjustment can not be obtained,
install a replacement thermostat and check
calibration.

Page 31 of 88 F24682 Rev. F (1118)

VC4G & VC6G SERIES FULL SIZE CONVECTION OVENS - SERVICE PROCEDURES AND ADJUSTMENTS

NOTE: Oven temperature must be below 450°F.

NOTE: If oven is equipped with "Cook and Hold"

option, set to Cook (normal cooking) before
continuing.

3. Set the temperature control to the maximum
setting.

4. Check machine data plate for correct voltage to
oven. Refer to diagram below for proper terminal
locations and voltages before checking the
control. Use the correct terminals for the
corresponding voltage.

5. Turn the power switch to ON.

Fig. 72

SOLID STATE TEMPERATURE
CONTROL TEST (VC4GD/6GD)

Certain procedures in this section
require electrical test or
measurements while power is
applied to the machine. Exercise
extreme caution at all times and
follow Arc Flash procedures. If test
points are not easily accessible,
disconnect power and follow
Lockout/Tagout procedures, attach
test equipment and reapply power to
test.

1. Remove the RIGHT SIDE PANEL.

NOTE: If right side panel is not accessible, this
component can be serviced by removing CONTROL
PANEL.

2. Place a thermocouple in the geometric center of
the oven cavity.

Fig. 73

6. Check for proper voltage across terminals COM
AC to 120VAC or COM AC to 208-240VAC for
power to the control.

A. If correct, proceed to step 7.

B. If incorrect, problem is not with the

temperature control. See
TROUBLESHOOTING.

7. Check relay voltages on the board:

A. For 120VAC controls - check across

OUTPUT RELAY terminal (left side) to
120VAC terminal for input to the internal
relay. Check across OUTPUT RELAY
terminal (right side) to 120 VAC for output
from the internal relay.

B. For 208-240VAC controls - check across

OUTPUT RELAY terminal (left side) to
208-240VAC terminal for input to the
internal relay. Check across OUTPUT
RELAY terminal (right side) to 208-240VAC
for output from the internal relay.

F24682 Rev. F (1118) Page 32 of 88

VC4G & VC6G SERIES FULL SIZE CONVECTION OVENS - SERVICE PROCEDURES AND ADJUSTMENTS

1) If input voltage to the internal relay is
correct, proceed to step 8. If input
voltage to the internal relay is not
present, problem is not with the
temperature control. See
TROUBLESHOOTING.

2) If output voltage from the internal relay
is correct proceed to step 8. If output
voltage from the internal relay is not
correct, check temperature probe as
outlined under TEMPERATURE
PROBE TEST (VC4GD/6GD).

8. Set the temperature control to the minimum
setting.

NOTE: Oven temperature must be above 300°F.

9. Check for zero (0) volts AC across terminals
OUTPUT RELAY terminal (right side) to 120VAC
or OUTPUT RELAY terminal (right side) to
208-240VAC for no output from the internal relay.

A. If correct, temperature control is functioning

properly.

B. If incorrect, check temperature probe as

outlined under TEMPERATURE PROBE
TEST (VC4GD/6GD).

1) If temperature probe is OK:

a. Turn the power switch OFF.

Disconnect the electrical power to
the machine and follow lockout /
tagout procedures.

b. Replace the temperature control

and check calibration as outlined
under SOLID STATE
TEMPERATURE CONTROL
CALIBRATION (VC4GD/6GD).

type. As temperature increases the resistance value
decreases.

1. Remove the Right Side Panel.

NOTE: If right side panel is not accessible, this
component can be serviced by removing the Control
Panel.

2. Place a shielded thermocouple in the geometric
center of the oven cavity and determine the
temperature in the oven cavity.

3. Remove the probe lead wires from the solid state
temperature control.

4. Test the probe with an ohmmeter.

A. If the measured resistance values are inside

the given tolerance then the probe is
functioning properly.

B. If the measured resistance values are

outside the given tolerance then replace the
probe and retest.

1) Check oven for proper operation.

5. Reverse procedure to install.

TEMP (°F) OHMS* TEMP (°F) OHMS*

77 90,000 360 822

240 4,077 380 656

260 3,016 400 529

280 2,266 425 424

300 1,726 450 334

320 1,332 475 266

340 1,041

(*) Resistance in ohms ± 10%

GAS PRESSURE ADJUSTMENT

(units up to February 2015)

TEMPERATURE PROBE TEST

(VC4GD/6GD)

Disconnect the electrical power to
the machine and follow lockout /
tagout procedures.

NOTE: The temperature probe used in conjunction

with the Solid State Temperature control is an RTD
(resistance temperature detector) of the Thermistor

Disconnect the electrical power to
the machine and follow lockout /
tagout procedures.

1. Turn gas supply off at manual shutoff valve.

2. Remove the Right Side Panel.

NOTE: If right side panel is not accessible, this
component can be serviced by removing the Control
Panel.

Page 33 of 88 F24682 Rev. F (1118)

VC4G & VC6G SERIES FULL SIZE CONVECTION OVENS - SERVICE PROCEDURES AND ADJUSTMENTS

3. Remove the plug from the manifold pressure
port.

FIRST GENERATION UNIT SHOWN (Before April

2005)

SECOND GENERATION UNIT SHOWN (After April

2005 thru February 2015)

4. Install hose barb adapter and attach manometer
tube.

FIRST GENERATION UNIT SHOWN (Before April

2005)

SECOND GENERATION UNIT SHOWN (After April

2005 thru February 2015)

5. Remove adjustment screw cap from the gas
valve and turn gas supply to the oven back on.

6. Plug the unit in and turn the power switch ON.

7. Set the temperature control to its highest setting

NOTE: The burner must be lit during test and
adjustment.

F24682 Rev. F (1118) Page 34 of 88

and allow burner to ignite.

VC4G & VC6G SERIES FULL SIZE CONVECTION OVENS - SERVICE PROCEDURES AND ADJUSTMENTS

8. Turn the set screw to obtain the proper gas
pressure (clockwise = pressure increase;
counterclockwise = pressure decrease).

NOTE: Accurate gas pressure adjustments can only
be made with the gas on and the burner lit.

PRESSURE READING (IN W.C.)

GAS

TYPE

Natural 3.5 7.0 5 14

Propane 10 11.0 11 14

NOTE: If the incoming line pressure to the valve is
less than the minimum stated, then the manifold

pressure can not be set correctly.

MANIFOLD

RECOMMEND MIN MAX

LINE

GAS VALVE PRESSURE CHECK

(units after February 2015)

Disconnect the electrical power to
the machine and follow lockout /
tagout procedures.

1. Turn gas supply off at manual shutoff valve.

2. Remove the RIGHT SIDE PANEL.

NOTE: If right side panel is not accessible, this
component can be serviced by removing the
CONTROL PANEL.

3. Remove the plug from the manifold pressure
port.

4. Install hose barb adapter and attach manometer
tube.

5. Turn gas supply to the oven back on.

6. Plug the unit in and turn the power switch ON.

7. Set the temperature control to its highest setting
and allow burner to ignite.

NOTE: The burner must be lit during test.

NOTE: Accurate gas pressure readings can only be

made with the gas on and the burner lit.

PRESSURE READING (IN W.C.)

GAS

TYPE

Natural 5.0 8.0 6 14

Propane 10 11.0 11 14

NOTE: If the incoming line pressure to the valve is
less than the minimum stated, then the manifold

pressure will not be maintained.

NOTE: If gas valve cap is removed, or reversed for
gas type, ensure sealing washer is installed between
the gas valve and cap.

NATURAL GAS

• If the incoming pressure to the valve is between

PROPANE

• If the incoming pressure to the valve is between

MANIFOLD

RECOMMEND MIN MAX

6” WC and 14” for Natural gas and the manifold
pressure is not maintaining 5” WC, and the cap
(1, Fig. 79) is correctly positioned, replace the
valve.

11” WC and 14” for Propane gas and the manifold
pressure is not maintaining 10” WC, and the cap
(1, Fig. 80) is correctly positioned, replace the
valve.

LINE

Fig. 78

Fig. 79

Page 35 of 88 F24682 Rev. F (1118)

VC4G & VC6G SERIES FULL SIZE CONVECTION OVENS - SERVICE PROCEDURES AND ADJUSTMENTS

DO NOT HOLD THE WIRE WITH YOUR HANDS
FOR THIS TEST. THE MANUAL GAS VALVE MUST
BE CLOSED.

3. Clamp the ignition cable in a manner that will
position the end of the cable 3/16" from the oven
frame (bare metal surface).

NOTE: It is critical that the cable be held 3/16" away
from the surface of the oven frame or sparking may
not occur even though the sparking circuit is
functioning properly.

Fig. 80

ITEM DESCRIPTION

1, Fig. 79

1, Fig. 80

Cap position for natural gas
(stamped NAT).

Cap position for propane gas
(stamped LP).

VERIFICATION OF SPARK AT

IGNITOR

Disconnect the electrical power to
the machine and follow lockout /
tagout procedures.

SHUT OFF THE GAS BEFORE SERVICING THE
UNIT.

1. Remove the Bottom Front Cover.

2. Disconnect the high voltage "ignition cable" from
the spark ignitor.

Fig. 82

4. Plug the oven in and set the temperature control
to the maximum setting.

5. Turn the power switch ON.

6. Sparking should occur after a 4 second delay, for
a duration of 7 seconds then repeat twice after a
15 second purge time. Arching from the ignition
cable to the oven frame should be observed.

DOOR SWITCH ADJUSTMENT

Disconnect the electrical power to
the machine and follow lockout /
tagout procedures.

1. Check the doors to make sure they have a .125
(1/8") gap between them and that the vertical
edge of the door is parallel to the vertical door
seal. If the doors are not positioned in this
manner, adjust the doors as described.

Fig. 81

F24682 Rev. F (1118) Page 36 of 88

VC4G & VC6G SERIES FULL SIZE CONVECTION OVENS - SERVICE PROCEDURES AND ADJUSTMENTS

Fig. 84

Figure shown below (Left Side) is starting at
Serial Number 481907146.

Fig. 83

2. Remove the .

3. Loosen the screws/bolts that secure the upper
door brackets just enough to allow door
movement.

Figure Shown below (Left Side) is ending at
Serial Number 481907145.

Fig. 85

4. Move the door until proper alignment is achieved
then tighten the screws/bolts on the upper door
bearing hardware.

5. Repeat and on the opposite door, if necessary.

6. Install .

BLOWER ADJUSTMENT

Disconnect the electrical power to
the machine and follow lockout /
tagout procedures.

SHUT OFF THE GAS BEFORE SERVICING THE
UNIT.

1. Remove the blower motor and mounting
assembly by following steps 1 through 8 as
outlined under BLOWER AND MOTOR.

Page 37 of 88 F24682 Rev. F (1118)

VC4G & VC6G SERIES FULL SIZE CONVECTION OVENS - SERVICE PROCEDURES AND ADJUSTMENTS

2. Loosen the motor mounting bolts.

3. Adjust the motor position until the blower is
parallel to and 1/4 inch away from the motor
mounting plate. Check for squareness of the
blower to the motor mounting plate at the top,
bottom, left and right of the blower.

A. If the blower is square then tighten motor

mounting bolts and proceed to Step 4.

B. If the blower is not square continue

adjusting until proper spacing is achieved
then tighten motor mounting bolts.

NOTE: If necessary, place shims between motor and
frame.

Fig. 86

4. Reverse the procedure to install.

DOOR ADJUSTMENT

Disconnect the electrical power to
the machine and follow lockout /
tagout procedures.

1. Check the doors to make sure they have a .125
(1/8") gap between them and that the vertical
edge of the door is parallel to the vertical door
seal. If the doors are not positioned in this
manner, adjust the doors as described.

Fig. 87

2. Remove the .

3. Loosen the screws/bolts that secure the upper
door brackets just enough to allow door
movement.

Figure Shown below (Left Side) is ending at
Serial Number 481907145.

F24682 Rev. F (1118) Page 38 of 88

VC4G & VC6G SERIES FULL SIZE CONVECTION OVENS - SERVICE PROCEDURES AND ADJUSTMENTS

A. Replace if bent. Do not bend strike plate.

B. If adjustment is necessary, loosen

fasteners, close doors and insure contact
between door inner surface and upper
horizontal seal. Slide door strike plate until
contact with roller latch is made. Tighten
strike plate fasteners.

Fig. 88

Figure shown below (Left Side) is starting at
Serial Number 481907146.

Fig. 89

4. Move the door until proper alignment is achieved
then tighten the screws/bolts on the upper door
bearing hardware.

5. Repeat and on the opposite door, if necessary.

6. Install

DOOR STRIKE ADJUSTMENT

(INDEPENDENT DOORS)

NOTE: For units with serial number starting with 48

made after 8/12/07 and serial number starting with 54
made after 8/26/07.

Fig. 90

3. Open and close the doors several times while
observing the roller latch and strike plate
operation.

A. Replace roller latch if malfunctioning as

outlined under ROLLER LATCH
ASSEMBLY (INDEPENDENT DOORS)
and adjust as outlined in this procedure.

4. Each oven door should open with a force of 8 to
25 pounds when pulled at the handle. The
adjustments must allow the doors to remain
closed during normal operation and allow
opening without exertion by the user.

DOOR CATCH BALL ADJUSTMENT

(INDEPENDENT DOORS)

NOTE: For units with serial number starting with 48

made before 8/13/07 and serial number starting with
54 made before 8/27/07.

Disconnect the electrical power to
the machine and follow lockout /
tagout procedures.

1. Remove Top Front Cover.

2. Open the doors and inspect door strike for proper
shape.

Page 39 of 88 F24682 Rev. F (1118)

Disconnect the electrical power to
the machine and follow lockout /
tagout procedures.

1. Remove Top Front Cover.

2. Open the doors and inspect door strike for proper
shape.

VC4G & VC6G SERIES FULL SIZE CONVECTION OVENS - SERVICE PROCEDURES AND ADJUSTMENTS

A. Doors should be centered and parallel at the

top and bottom in the oven cavity opening
as outlined under DOOR ADJUSTMENT.

6. Open right side door and view the left side catch
ball and door strike position. Ensure catch ball is
resting upon the angular surface of door strike.
Repeat on opposite door.

NOTE: If catch ball is striking the flat surface on door
strike, shims will be required under the door catch
assembly.

NOTE: The catch ball should make contact near the
center of door strike.

A. If adjustment is necessary, loosen mounting

screws then slide door strike from front to
back until roller ball rests upon the angular
surface of the door strike. Tighten screws
and check operation.

B. If proper adjustment cannot be achieved,

add shims beneath the door strike. Repeat

Fig. 91

A. Replace if bent and adjust as outlined in this

procedure.

3. Open and close the doors several times while
observing the catch ball operation.

A. Replace if malfunctioning and adjust as

outlined in this procedure.

NOTE: Shims may be required under the door strike,
before the proper door tension adjustment can be set.

4. Apply lubricant at the top of the door catch
assembly to lubricate the internal spring. See
LUBRICATION.

NOTE: DO NOT BEND THE DOOR STRIKE.

7. Each oven door should open with a force of 8 to

NOTE: The amount of tension on catch ball
determines the opening force of door.

step 6.

25 pounds when pulled at the handle. The
adjustment must allow the doors to remain
closed during normal operation and allow
opening without exertion by the user.

A. Adjust catch ball tension as follows:

1) Turn set screw inside the catch
assembly housing clockwise to
increase tension on catch ball and
counterclockwise to decrease tension
on catch ball.

Fig. 92

5. Close the doors and check them for proper
alignment.

F24682 Rev. F (1118) Page 40 of 88

VC4G & VC6G SERIES FULL SIZE CONVECTION OVENS - SERVICE PROCEDURES AND ADJUSTMENTS

Fig. 93

2) Continue adjustment until proper door
operation is achieved.

DOOR CHAIN ADJUSTMENT

(SIMULTANEOUS DOORS)

Introduction

When the oven doors are in proper adjustment, as the
doors come together, the right door will lead the left
door in closing by about 1/4 inch. The doors will feel
like they are self closing the last ½ inch of travel.

Procedure

1. Remove the Bottom Front Cover .

2. Close doors and check door chain for factory
setting.

A. Turnbuckles should be 5 to 5 ½ inches

apart.

B. Short eye bolt should be connected to the

end of the chain that goes to the front of the
sprocket.

C. 2 links of the chain should not be engaged

at the rear of the sprocket.

D. Chain must be tight enough that the doors

move simultaneously when opened or
closed.

Fig. 94

4. If right door does not lead the left door in closing:

A. Loosen locknuts on both turnbuckles.

B. Loosen left turnbuckle.

C. Tighten right turnbuckle.

D. Tighten locknuts on both turnbuckles.

5. If the right door leads the left door by more than
3/8 inch:

A. Loosen locknuts on both turnbuckles.

B. Loosen right turnbuckle.

C. Tighten left turnbuckle.

D. Tighten locknuts on both turnbuckles.

6. Check door for proper operation.

NOTE: The locknuts must be tight during testing or
the adjustment will not hold.

A. If doors do not close properly, repeat Step

4, 5 and 6.

B. If doors operate properly, continue to step 7.

7. Install the lower front cover.

E. When the doors are opened, the

turnbuckles will move away from each other.

F. The stop cable must be positioned where it

moves freely and does not get pinched.

3. Position door chain assembly to factory setting if
the conditions in step 2 are not met.

Page 41 of 88 F24682 Rev. F (1118)

COMPUTER CONTROL (VC4GC/

VC6GC)

Operation

Refer to the Instructions Manual for specific operating
instructions.

VC4G & VC6G SERIES FULL SIZE CONVECTION OVENS - SERVICE PROCEDURES AND ADJUSTMENTS

Setup Mode
NOTE: Use the setup mode to verify that the control

is configured to the factory settings which result in the
proper operation of the oven. If the CAL1 parameter
is other than zero, determine if it is still needed before
resetting to zero. See COMPUTER CONTROL
CALIBRATION (VC4GC/VC6GC).

Changing the C_F, InP1, rL1 & rH1 parameters will
default all menus.

1. Use this key sequence to access the setup mode.

Up arrow; Rack 1; Temperature; Temperature;
Down arrow; Rack 1

Fig. 95

2. Once in the setup mode the display will alternate
between the parameter and programmed data.

• To change data to the factory setting, use

the arrow keys.

• To select the next parameter, press the

Rack 1 key.

• After the last Parameter and Data is viewed,

press the Rack 1 key a final time to exit the
setup mode and return to operations mode.
The current set point temperature will be
displayed.

MENU

Exit Setup Mode
and return to
Operation Mode.

Probe Test

1. Set the control to 350°F.

2. Access the back of the control panel to
disconnect the probe lead wires.

3. Install a jumper wire across the probe terminals.
This will simulate room temperature.

A. If the heat light comes on and the actual

temperature is room temperature, replace
the probe.

B. If the heat light does not come on or the

actual temperature is not room temperature,
replace the control.

Solid State Relay Test

1. Remove the Right Side Panel.

2. Set the temperature to 350°F or high enough to
keep the heat ON for several minutes.

3. Check for +5 VDC on input side of SSR
(terminals 3 & 4).

A. If +5 VDC is present, continue to step 4.

B. If no voltage is present, computer control is

not functioning properly.

ALTERNATING ON DISPLAY

PARAMETER DATA

set point temperature is
displayed or if call for heat,
dashes (----) displayed.

• After 1 minute of no key activations, the
control will return to operation mode.

3. Listed are the parameters and data you should
find.

MENU

Celsius_Fahrenheit C_F F

Guard Band gb 4000

Temperature
Compensation

Input Type 1 InP1 J

Range Low 1 rL1 75

Range High 1 rH1 500

Hysteresis HYS1 3

Calibration Offset CAL1 0

F24682 Rev. F (1118) Page 42 of 88

ALTERNATING ON DISPLAY

PARAMETER DATA

tcnP OFF

4. Check for 120 VAC at load side of SSR (terminals

5. Re-assemble oven and check for proper

1. Place a thermocouple in the geometric center of

2. Press the set key then temperature key to enter

1 & 2).

A. If no voltage is present, solid state relay is

not functioning properly.

1) Replace the SSR and check for proper
operation.

B. If 120 VAC is present, component is

functioning properly.

operation.

COMPUTER CONTROL

CALIBRATION (VC4GC/VC6GC)

the oven cavity.

the temperature set mode.

VC4G & VC6G SERIES FULL SIZE CONVECTION OVENS - SERVICE PROCEDURES AND ADJUSTMENTS

A. The display will alternate between the term

"StPt" (set point) and the current oven
temperature setting.

B. Press the up or down arrow keys to make

the proper selection.

C. Press the set key again to save the change

and exit the temperature set mode.

3. Allow the oven temperature to stabilize (normally
3 cycles).

4. Set the ON-OFF-COOL DOWN switch to ON.

A. If the set point temperature is 350°F,

proceed to step 4.

B. If the set point temperature is other than

350°F, proceed to step 3 to change the
temperature.

5. Compare the controls set point temperature to
the thermocouple meter reading when the heat
light goes out.

A. A temperature variance more than 5°F

indicates an adjustment is needed.

1) To make the adjustment, proceed to
step 6.

6. Enter the .

A. Advance through the menu until CAL1

(Calibration Offset) appears.

1) If the thermocouple reading is higher
than set point temperature, press the
down arrow key and enter a negative
offset value that is equal to the number
of degrees above the 5°F tolerance.

2) If the thermocouple reading is lower
than set point temperature, press the
up arrow key and enter a positive offset
value that is equal to the number of
degrees below the 5°F tolerance.

3) Exit the setup mode.

7. Allow the oven to cycle at least two times
between adjustments.

A. If the temperature variance still differs

more than 5°F from the set point, verify the
correct calibration offset value was entered
and retained.

1) Adjust the calibration offset value as
outlined in step 6, until the cycling
temperature is within tolerance.

2) If temperature variance is less than
5°F, computer control is functioning
properly.

B. If the above adjustment cannot be obtained,

replace the computer control and check for
proper operation.

FLAME SENSE CURRENT TEST

Page 43 of 88 F24682 Rev. F (1118)

VC4G & VC6G SERIES FULL SIZE CONVECTION OVENS - SERVICE PROCEDURES AND ADJUSTMENTS

Disconnect the electrical power to the machine and follow lockout / tagout procedures.

1. Remove screws securing right side of the top front cover, bottom front cover and control panel.

2. Remove right side panel mounting screws.

Fig. 96

3. Pull right side panel out from the bottom then down to remove.

4. Remove top screw and loosen bottom screw securing the ignition control module mounting bracket.

Fig. 97

5. Position bracket horizontally by pulling forward 90 degrees, with ignition module facing up for accessibility.

6. Re-apply power to unit.

7. Set VOM meter to read Micro Amps.

8. Place red (Positive) lead on FC+ and black (Negative) lead on FC- terminals on ignition module to test.

F24682 Rev. F (1118) Page 44 of 88

VC4G & VC6G SERIES FULL SIZE CONVECTION OVENS - SERVICE PROCEDURES AND ADJUSTMENTS

Fig. 98

Fig. 99

9. Set the oven to call for heat and measure the Micro Amps reading.

Micro Amp reading from the flame sensor should measure a minimum of 0.7 Micro Amps to maintain burner
ignition.

• If Micro amp reading is correct and the burner lights but does not maintain flame, replace ignition module.

• If Micro Amp reading is NOT correct, check wiring from flame sensor/igniter to the ignition module. If wiring
is OK, adjust, clean or replace flame sensor/igniter.

10. Install ignition control module mounting bracket and right panel.

11. Verify operation.

Page 45 of 88 F24682 Rev. F (1118)

VC4G & VC6G SERIES FULL SIZE CONVECTION OVENS - ELECTRICAL OPERATION

ELECTRICAL OPERATION

COMPONENT FUNCTION

Power Switch (S1) .... Determines the mode of operation; ON, OFF, or COOL DOWN.

Oven Light Switch

(S2) ...................

Fan Speed Switch Hi/

Low (S3) ..............

Function Switch

(S3) ...................

Buzzer ................ Signals the end of a Normal ROAST cycle (normal cooking) when time expires on the

Normal Roast

Timer .................

Roast & Hold Timer ... When the function switch (S3) is set to ROAST & HOLD, this timer must used for ROAST

Door Switch .......... Allows the oven to operate when the doors are closed but stops the oven from operating

Controls the oven cavity lights.

Controls blower motor speed between Hi and Low settings. Available on standard models
VC4GS/6GS or VC4GD/6GD. On models with the ROAST & HOLD option (S3) becomes
the Function Switch.

Selects the cooking mode of the oven between Normal ROAST or ROAST & HOLD and
is used in conjunction with the ROAST & HOLD timer during ROAST & HOLD cooking.
The selected mode also determines the fixed blower speed of Hi for Normal ROAST and
Low for ROAST & HOLD. In ROAST & HOLD mode only, energizes the hold relay (R2).
Available on models with ROAST & HOLD option only. On Standard models (S3)
becomes the Function Switch.

Normal ROAST timer.

Counts the ROAST time (normal cooking) of the product and signals the buzzer at the
end of the cycle. On ROAST & HOLD models only, when the function switch (S3) is set
to Normal ROAST, this timer is used.

& HOLD cooking. When the ROAST (then hold) time expires and the function switch is
set to ROAST & HOLD, this timer is used to transfer control of the oven temperature to
the Hold thermostat. Available on models with Roast & Hold option only.

when the doors are opened.

Blower Motor ......... Operates the oven cavity blower (convection fan). Also, an internal centrifugal switch on

the motor is utilized to allow the connection of power to the heat relay (R3) when the
motor is at operating speed.

Motor Speed Relay

(R1) ...................

Hold Relay (R2) ....... Hold relay (R2) supplies power to the Hold thermostat for maintaining the fixed hold

Transformer (T1) ..... Provides 24VAC power to the ignition control module and heating circuit.

Solid State
Temperature Control

(VC4GD/6GD) .........

High Limit

Thermostat ...........

Computer Control

(VC4GC/6GC) .........

Supplies power to the blower motor through (R1) relay contacts. Available on models
with Cook & Hold option only.

temperature in the oven cavity, after the ROAST & HOLD time expires.

Monitors temperature sensor and regulates the oven cavity temperature by controlling
the heat relay (R3) through the blower motor centrifugal switch contacts.

Protects the oven from temperatures above 550°F by removing power from the 1st valve
(safety) on the dual solenoid gas valve which stops the flow of gas to the burner. Auto
resets at 500°F.

Monitors temperature sensor and regulates the oven cavity temperature by controlling
the heat relay (R1) through the blower motor centrifugal switch contacts. Also, counts the
ROAST time (normal cooking) of the product and signals the electronic alarm at the end
of the cycle. If ROAST & HOLD mode is selected, when the ROAST (then hold) time
expires, the oven heating stops and the oven enters HOLD mode. Once the oven cavity
temperature drops to 150°F, the heat comes back on and the oven cycles at this
temperature to hold the cooked product. Roast & Hold is standard on computer models.

F24682 Rev. F (1118) Page 46 of 88

VC4G & VC6G SERIES FULL SIZE CONVECTION OVENS - ELECTRICAL OPERATION

SSR1 & SSR2 (VC4GC/

6GC) ..................

Ignition Control

Module ...............

Igniter/Flame

Sense .................

Power On Light ....... Lit whenever the power switch (S1) is turned to ON or Cool Down mode.

Heat Light ............ Lit whenever temperature control is calling for heat.

No Ignition Light ...... Lit when power is turned ON, during ignition trial & gas purge time and when no flame is

Temperature Probe ... Senses the oven temperature for the solid state temperature control or the computer

When SSR1 is energized by computer control, connects power to blower motor for Hi fan
speed operation in normal ROAST mode. In ROAST & HOLD Mode only, SSR1 is de­energized and SSR2 is energized by computer control and connects power to blower
motor for Low fan speed operation.

Controls the gas ignition cycle - Energizes the 2nd valve (main) on the dual solenoid gas
valve, generates spark for burner ignition, monitors the presence of a flame and controls
the No Ignition light. The ignition times are: 4 second self diagnostic test (initial power
ON); 7 second ignition trial; 3 ignition trials with a 15 second purge between each trial.

Ignites the gas and senses the presence of a flame. The flame presence generates a
micro-amp "flame sense" current that is monitored by the ignition control module. A flame
sense current of 0.7 micro amp (minimum) is required to maintain burner ignition.

detected by flame sensor. If the oven fails to ignite after 3 attempts, it will remain lit until
power is reset.

control. On VC4GD/6D models, converts the temperature into a resistance valve which
is monitored by the temperature control board. The probe is an RTD (resistance
temperature detector) of the Thermistor type. As temperature increases the resistance
value decreases. On VC4GC/6C models, the probe is a J type thermocouple.

Gas Valve (Dual

Solenoid) .............

Cooling Fan .......... Circulates cooler air from rear of oven forward to cool components in the control area.

Mechanical
Temperature Control
KX thermostat

(VC4GS/6GS) .........

Hold Thermostat

(KX) ...................

Allows gas flow to the burner when the 1st valve (safety) and 2nd valve (main) solenoid
coils are both energized.

Regulates the oven cavity temperature by controlling the heat relay (R3) through the
blower motor centrifugal switch contacts. On ROAST & HOLD models only, power is first
connected through one set of (R4) normally closed contacts (N.C.) then through the
centrifugal switch contacts on the motor.

Holds the oven cavity temperature at 160°F after ROAST (then hold) time expires. For
the oven to operate on the Hold thermostat, the ROAST & HOLD timer must be used and
the Function Switch (S3) must be set to. Available on models with Roast & Hold option
only.

COMPONENT LOCATION

ENDING AT SERIAL NUMBER 481907145

Page 47 of 88 F24682 Rev. F (1118)

VC4G & VC6G SERIES FULL SIZE CONVECTION OVENS - ELECTRICAL OPERATION

VC4GS/6GS - Plug, Socket and Components (Standard Controls)

F24682 Rev. F (1118) Page 48 of 88

VC4G & VC6G SERIES FULL SIZE CONVECTION OVENS - ELECTRICAL OPERATION

VC4GD/6GD - PLUG, SOCKET AND COMPONENTS (STANDARD CONTROLS) ENDING AT SERIAL NUMBER

481907145

Page 49 of 88 F24682 Rev. F (1118)

VC4G & VC6G SERIES FULL SIZE CONVECTION OVENS - ELECTRICAL OPERATION

VC4GD/6GD - PLUG, SOCKET AND COMPONENTS (STANDARD CONTROLS) STARTNG AT SERIAL

NUMBER 481907146

F24682 Rev. F (1118) Page 50 of 88

VC4G & VC6G SERIES FULL SIZE CONVECTION OVENS - ELECTRICAL OPERATION

VC4GS/6GS, VC4GD/6GD - Plug, Socket and Components (Roast & Hold Option)

Page 51 of 88 F24682 Rev. F (1118)

VC4G & VC6G SERIES FULL SIZE CONVECTION OVENS - ELECTRICAL OPERATION

VC4GC/6GC - PLUG, SOCKET AND COMPONENTS (ROAST & HOLD STANDARD

SEQUENCE OF OPERATION

VC4GS, VC6GS With Roast & Hold Option
(Mechanical KX Thermostat)

Schematic diagram 5304 will be used to explain the
electrical sequence of operation for both the Normal
ROAST cycle (normal cooking) and the ROAST &
HOLD cycle.

Normal Roast Cycle

1. Conditions.

A. Oven connected to correct voltage.

1) L1 (HOT) to power switch (S1).

2) L2 (NEUTRAL or SECOND LINE) to
one side of the following components:
power ON light, heat light, oven cavity
lights, buzzer, ROAST timer motor
(normal cooking), ROAST & HOLD
timer motor, heat relay coil (R3),
convection fan motor common (C),
transformer primary (T1), relay coil
(R4), motor speed (Hi/Low) relay coil
(R1), hold relay coil (R2) and the
component cooling fan.

B. Oven properly grounded.

C. Gas supply valve ON.

D. Gas combination control valve ON.

E. Power switch (S1) OFF.

F. Function switch (S3) set to Normal ROAST

cycle.

G. Oven light switch (S2) ON/OFF (position

has no affect on the function of the Normal
ROAST cycle).

H. Control thermostat dial in the OFF position

(OPEN).

I. High limit switch CLOSED.

J. Cook timer (normal cooking) in the OFF

position.

K. Roast and Hold timer in the OFF position.

L. Oven doors CLOSED.

1) Door switch contacts CLOSED.

M. Oven cavity temperature below 140°F.

2. Set thermostat to desired Normal ROAST
temperature (normal cooking).

A. Internal contacts close.

3. Power switch (S1) turned ON.

F24682 Rev. F (1118) Page 52 of 88

VC4G & VC6G SERIES FULL SIZE CONVECTION OVENS - ELECTRICAL OPERATION

A. Power to motor speed (Hi/Low) relay (R1)

normally open (N.O.) contacts and hold
relay (R2) common (C).

B. Component cooling fan energized.

C. Power ON light (Amber) comes ON.

D. Power to one side of the following

components: Normal ROAST timer terminal
1, ROAST & HOLD timer terminal 1,
transformer primary (T1).

NOTE: Power is available to the oven light switch
(wire #20) to turn the oven cavity lights ON when the
light switch is turned ON; and power is available to the
normally open N.O. side (wire #28) of the door switch
contacts and connects power to additional
components when the door switch contacts are
CLOSED (door closed).

1) Transformer (T1) energized.

a. Power (24VAC) to one side of the

following components: heat relay
(R3) normally open (N.O.)
contacts, high limit --- connected
through the normally closed
(N.C.) contacts to the 1st valve
(safety) on the dual solenoid gas
valve.

a) 1st valve (safety) on the gas

valve energized.

a) Power is connected through

the function switch (S3)
contacts and the convection
fan motor is energized (fan
speed Hi).

b. When the convection fan motor

reaches operating speed, the
centrifugal switch on the motor
closes. The heat relay (R3) is then
energized, R3 relay contacts
normally open (N.O.) close and
the heating circuit is powered.

a) Ignition control module is

energized.

b) No ignition light (red) comes

ON, module performs a self
diagnostic test for 4 seconds,
2nd valve (main) on the gas
valve is energized. Gas
starts to flow to the burner,
sparking begins, the "no
ignition" light goes out and
burner lights. Sparking
continues for up to 7 seconds
or until a flame is
established. If a flame is
"sensed", the "no ignition"
light stays out and burner
remains lit.

NOTE: Gas does not flow to the burner until the 2nd
valve (main) is energized.

2) With door switch closed, power is
connected back through a second set
of contacts on the power switch (S1),
through the thermostat contacts,
through one set of relay R4 normally
closed (N.C.) contacts, to one side of
the centrifugal switch on the
convection fan motor.

a. Heat light (clear) comes ON.

3) Power is also connected through the
other set of relay R4 normally closed
(N.C.) contacts to the other side of
motor speed relay (R1).

a. Motor speed relay (R1)

energized, contacts change state
and the normally open (N.O.) set
of contacts close.

If a flame is not "sensed"
after 7 seconds of sparking,
the "no ignition" light comes
back on, 2nd valve (main) on
the gas valve is de-energize
and gas flow to the burner
stops. Ignition trial cycle
repeats after a 15 second
purge between cycles for two
additional tries before
locking out. To reset after a
lockout, turn power switch
(S1) OFF then ON.

4. Oven reaches set temperature and thermostat
opens.

A. Heat light goes out.

B. Power removed from heat relay (R3).

1) R3 normally open (N.O.) contacts
open.

a. Power removed from 2nd valve

(main) on the gas valve and gas
flow to the burner stops.

Page 53 of 88 F24682 Rev. F (1118)

VC4G & VC6G SERIES FULL SIZE CONVECTION OVENS - ELECTRICAL OPERATION

5. The oven will continue to cycle on the thermostat
until the doors are opened or the power switch
(S1) is turned to the OFF or COOL DOWN
position.

Timer Cycle (Normal Roast Cooking)
NOTE: The ROAST timer (normal cooking) operates

independently of the heating cycle. Additional time
can be set or the timer can be turned OFF throughout
the cooking cycle.

1. With the power switch turned ON, power is
supplied to timer.

2. Set ROAST timer to desired time (normal
cooking).

A. Contacts 1 & 3 close, timer motor is

energized and timing "down" begins.

3. Time expires on ROAST timer (normal cooking).

A. Contacts 1 & 3 open, timer motor is de-

energize and timing stops.

B. Contacts 1 & 4 close.

1) Buzzer energized and sounds.

NOTE: The buzzer continues to sound until the timer
dial is set to the OFF position or additional time is set.

H. Control thermostat in the OFF position

(OPEN).

I. High limit switch CLOSED.

J. Roast timer (normal cooking) in the OFF

position..

K. Roast and Hold timer in the OFF position.

L. Oven doors Closed.

1) Door switch contacts CLOSED.

M. Oven cavity temperature below 140°F.

2. Set controlling thermostat to desired ROAST
then Hold temperature (Roast & Hold cooking).

NOTE: This is considered first stage cooking in the
ROAST & HOLD cycle.

A. Internal contacts close.

3. Power switch (S1) turned ON.

A. Power to motor speed (Hi/Low) relay (R1)

normally open (N.O.) contacts and hold
relay (R2) common (C).

B. Component cooling fan energized.

C. Power ON light (Amber) comes ON.

Roast and Hold Cycle
NOTE: Refer to the Installation and Operation Manual

for a detailed explanation of ROAST & HOLD cooking.

1. Conditions.

A. Oven connected to correct voltage.

1) L1 (HOT) to power switch (S1).

2) L2 (NEUTRAL or SECOND LINE) to
one side of the following components:
power ON light, heat light, oven cavity
lights, buzzer, "Cook" timer motor
(normal cooking), "Cook & Hold" timer
motor, heat relay coil (R3), convection
fan motor (C), transformer primary
(T1), relay coil (R4), motor speed relay
coil (R1), hold relay coil (R2) and the
component cooling fan.

B. Oven properly grounded.

C. Gas supply valve ON.

D. Gas combination control valve ON.

E. Power switch (S1) OFF.

D. Power to one side of the following

components: "Cook" timer terminal 1, "Cook
& Hold" timer terminal 1, transformer
primary (T1).

NOTE: Power is available to the oven light switch
(wire #20) to turn the oven cavity lights ON when the
light switch is turned ON; and power is available to the
normally open N.O. side (wire #28) of the door switch
contacts and connects power to additional
components when the door switch contacts are
CLOSED (door closed).

1) Transformer (T1) energized.

a. Power (24VAC) to one side of the

following components: heat relay
(R3) normally open (N.O.)
contacts, high limit—connected
through the normally closed
(N.C.) contacts to the 1st valve
(safety) on the dual solenoid gas
valve.

a) 1st valve (safety) on the gas

valve energized.

F. Function switch (S3) set to "Cook & Hold"

cycle.

G. Oven light switch (S2) ON/OFF (position

has no affect on the function of the Cook &
Hold cycle).

F24682 Rev. F (1118) Page 54 of 88

NOTE: 1st valve (safety) on the gas valve energized.

VC4G & VC6G SERIES FULL SIZE CONVECTION OVENS - ELECTRICAL OPERATION

2) With door switch closed, power is
connected through a second set of
contacts on the power switch (S1),
through the thermostat contacts,
through one set of relay R4 normally
closed (N.C.) contacts, to one side of
the centrifugal switch on the
convection fan motor.

a. Heat light (clear) comes ON

3) Power is also connected through the
another set of relay R4 normally closed
(N.C.) contacts to the other side of
motor speed relay (R1).

a. Motor speed relay (R1)

energized, contacts change state
and the normally open (N.O.) set
of contacts close.

a) Convection fan motor

energized (fan speed low).

NOTE: In the ROAST & HOLD cycle, the fan speed
is fixed at low.

b) When the convection fan

motor reaches operating
speed, the centrifugal switch
on the motor closes. The
heat relay (R3) is then
energized, R3 relay contacts
normally open (N.O.) close
and the heating circuit is
powered.

1. Ignition control module
is energized.

2. No ignition light (red)
comes ON, module
performs a self
diagnostic test for 4
seconds, 2nd valve
(main) on the gas valve
is energized. Gas starts
to flow to the burner,
sparking begins, the "no
ignition" light goes out
and burner lights.
Sparking continues for
up to 7 seconds or until
a flame is established. If
a flame is "sensed", the
"no ignition" light stays
out and burner remains
lit.

If a flame is not
"sensed" after 7
seconds of sparking,
the "no ignition" light
comes back on, 2nd
valve (main) on the gas
valve is de-energize
and gas flow to the
burner stops. Ignition
trial cycle repeats after
a 15 second purge
between cycles for two
additional tries before
locking out. To reset
after a lockout, turn
power switch (S1) OFF
then ON.

4. Oven reaches set temperature and controlling
thermostat opens.

A. Heat light goes out.

B. Power removed from heat relay (R3).

1) R3 normally open (N.O.) contacts
open.

a. Ignition control module de-

energize.

a) Power removed from 2nd

valve (main) on the gas valve
and gas flow to the burner
stops.

NOTE: This is considered first stage cooking in the
ROAST AND HOLD cycle.

5. The oven will continue to cycle on the controlling
thermostat until one of the following occurs:
ROAST & HOLD time (R & H cooking) expires
which allows the oven to go into Hold mode;
Power switch (S1) is turned to the OFF or COOL
DOWN position or the doors are opened.

Timer Cycle (Roast & Hold Cooking))
NOTE: The ROAST & HOLD timer operates

independently of the heating cycle until time expires.
Regulation of the oven temperature is then transferred
to the Hold thermostat until one of the following
occurs: ROAST & HOLD timer is turned OFF and the
function switch (S3) is turned back to Normal ROAST
(normal cooking) or power switch (S1) is turned to the
OFF or COOL DOWN position.

1. With the power switch turned ON, power is
supplied to timer.

2. Set ROAST & HOLD timer to desired time (Roast
& Hold cooking).

Page 55 of 88 F24682 Rev. F (1118)

VC4G & VC6G SERIES FULL SIZE CONVECTION OVENS - ELECTRICAL OPERATION

NOTE: To Roast then Hold the cooked product at a
fixed temperature, the Roast & Hold timer must be
used and the function switch (S3) must also be set to
Roast & Hold as indicated under step1 conditions for
the Roast & Hold cycle.

A. Contacts 1 & 3 close, timer motor is

energized and timing "down" begins.

3. Time expires on Roast & Hold timer.

A. Contacts 1 & 3 open, timer motor is de-

energize and timing stops.

B. Contacts 1 & 4 close.

1) If the oven was heating, then the gas
burner and heat light go out; If the oven
was not heating, then the gas burner
and heat light remain out.

2) Hold relay (R2) is energized, R2
contacts change state and the normally
open (N.O.) contacts close.

a. Power to one side of hold

thermostat.

NOTE: When temperature is above 160°F (±12) the
hold thermostat contacts are open.

3) Relay R4 is energized, R4 contacts
change state and both sets of normally
closed (N.C.) contacts transfer to the
normally open (N.O.) position. Power is
not transferred until the hold
thermostat contacts close.

NOTE: This is considered second stage cooking in
the ROAST AND HOLD cycle where the stored heat
in the oven continues to cook the product.

4. Oven temperature falls below 160°F (±12) and
hold thermostat contacts close.

a. Heat relay (R3) contacts (N.O.)

close and the heating circuit is
powered.

a) Ignition control module is

energized.

b) No ignition light (red) comes

ON, module performs a self
diagnostic test for 4 seconds,
2nd valve (main) on the gas
valve is energized. Gas
starts to flow to the burner,
sparking begins, the "no
ignition" light goes out and
burner lights. Sparking
continues for up to 7 seconds
or until a flame is
established. If a flame is
"sensed", the "no ignition"
light stays out and burner
remains lit.

If a flame is not "sensed"
after 7 seconds of sparking,
the "no ignition" light comes
back on, 2nd valve (main) on
the gas valve is de-energize
and gas flow to the burner
stops. Ignition trial cycle
repeats after a 15 second
purge between cycles for two
additional tries before
locking out. To reset after a
lockout, turn power switch
(S1) OFF then ON.

5. Oven reaches the fixed "Hold" temperature and
the hold thermostat opens.

A. Heat light goes out.

A. Heat light comes ON.

B. Motor speed relay (R1) is energized through

one set of R4 (N.C.) contacts.

1) Convection fan motor energized (fan
speed low).

C. Power is applied to one side of the

centrifugal switch on the convection fan
motor through the other set of R4 (N.C.)
contacts.

D. When the convection fan motor reaches

operating speed, the centrifugal switch on
the motor closes.

1) Heat relay (R3) is energized.

F24682 Rev. F (1118) Page 56 of 88

B. Power removed from heat relay (R3) and

the contacts open (N.O.).

1) Ignition control module de-energized.

a. Power removed from 2nd valve

(main) on the gas valve and gas
flow to the burner stops.

C. Power is also removed from motor speed

relay (R1).

1) Convection fan motor de-energized
and fan stops rotating.

VC4G & VC6G SERIES FULL SIZE CONVECTION OVENS - ELECTRICAL OPERATION

6. The oven will continue to cycle on the hold
thermostat until the "Cook & Hold timer is turned
to the OFF position, the function switch (S3) is
changed back to "Cook" (normal cooking) or the
power switch (S1) is turned to the OFF or COOL
DOWN position.

VC4GD, VC6GD With Roast & Hold Option (Solid
State Temperature Control)

Schematic diagram 5306 will be used to explain the
electrical sequence of operation for both the Normal
ROAST cycle (normal cooking) and the ROAST &
HOLD cycle.

Normal Roast Cycle

1. Conditions.

A. Oven connected to correct voltage.

1) L1 (HOT) to power switch (S1).

2) L2 (NEUTRAL or SECOND LINE) to
one side of the following components:
power ON light, heat light, temperature
control board terminal 9 (120VAC) or
terminal 10 (208- 240VAC), oven
cavity lights, buzzer, "Cook" timer
motor (normal cooking), "Cook & Hold"
timer motor, heat relay coil (R3),
convection fan motor common (C),
transformer primary (T1), motor speed
(Hi/Low) relay coil (R1), hold relay coil
(R2) and the component cooling fan.

3. Power switch (S1) turned ON.

A. Component cooling fan energized.

B. Power ON light (Amber) comes ON.

C. Power to one side of the following

components: Normal ROAST timer terminal
1, ROAST & HOLD timer terminal 1,
transformer primary (T1).

NOTE: Power is available to the oven light switch
(wire #20) to turn the oven cavity lights ON when the
light switch is turned ON; and power is available to the
normally open N.O. side (wire #28) of the door switch
contacts and connects power to additional
components when the door switch contacts are
CLOSED (door closed).

1) Transformer (T1) energized.

a. Power (24VAC) to one side of the

following components: heat relay
(R3) normally open (N.O.)
contacts, high limit --- connected
through the normally closed
(N.C.) contacts to the 1st valve
(safety) on the dual solenoid gas
valve.

a) 1st valve (safety) on the gas

valve energized.

NOTE: Gas does not flow to the burner until the 2nd
valve (main) is energized.

B. Oven properly grounded.

C. Gas supply valve ON.

D. Gas combination control valve ON.

E. Power switch (S1) OFF.

F. Function switch (S3) set to "Cook" cycle.

G. Oven light switch (S2) ON/OFF (position

has no affect on the function of the "Cook"
cycle).

H. Temperature control dial set to lowest

temperature (fully counterclockwise).

I. High limit switch CLOSED.

J. Roast timer (normal cooking) in the OFF

position.

K. Roast and Hold timer in the OFF position.

L. Oven doors Closed.

1) Door switch contacts CLOSED.

M. Oven cavity temperature below 140°F.

2. Set temperature control dial to desired ROAST
then HOLD temperature (Roast & Hold cooking).

2) With door switch closed, power is
applied to motor speed (Hi/Low) relay
(R1) normally open (N.O.) contacts
and hold relay (R2) common (C).

a. Motor speed relay (R1) is

energized through hold relay (R2)
normally closed contacts (N.C.).
Relay contacts (R1) change state
and the normally open (N.O.) set
of contacts close.

a) Power is connected through

the function switch (S3)
contacts and convection fan
motor is energized (fan
speed hi).

b) When the convection fan

motor reaches operating
speed, the centrifugal switch
(N.O.) on the motor closes.

c) Power to normally open

(N.O.) side of internal relay
contacts (terminal 7) on the
temperature control board.

Page 57 of 88 F24682 Rev. F (1118)

VC4G & VC6G SERIES FULL SIZE CONVECTION OVENS - ELECTRICAL OPERATION

3) Power is also connected back through
a second set of contacts on the power
switch (S1) to terminal 8 on the
temperature control board.

a. Solid state temperature control

energized. If the oven
temperature is below set point,
the temperature control will
energize its internal relay. The
normally open (N.O.) contacts
close and apply power to the
following components:

a) Heat light (clear) comes ON.

b) Power is connected through

the centrifugal switch
contacts on the convection
fan motor, heat relay (R3) is
energized, (R3) contacts
(N.O.) close and the heating
circuit is powered.

c) Ignition control module is

energized.

d) No ignition light (red) comes

ON, module performs a self
diagnostic test for 4 seconds,
2nd valve (main) on the gas
valve is energized. Gas
starts to flow to the burner,
sparking begins, the "no
ignition" light goes out and
burner lights. Sparking
continues for up to 7 seconds
or until a flame is
established. If a flame is
"sensed", the "no ignition"
light stays out and burner
remains lit. If a flame is not
"sensed" after 7 seconds of
sparking, the "no ignition"
light comes back on, 2nd
valve (main) on the gas valve
is de-energize and gas flow
to the burner stops. Ignition
trial cycle repeats after a 15
second purge between
cycles for two additional tries
before locking out. To reset
after a lockout, turn power
switch (S1) OFF then ON.

4. Oven reaches set temperature.

A. Temperature control de-energizes internal

relay and the normally open (N.O.) contacts
OPEN.

F24682 Rev. F (1118) Page 58 of 88

5. The oven will continue to cycle on the

Timer Cycle (Normal Roast Cooking)
NOTE: The ROAST timer (normal cooking) operates

independently of the heating cycle. Additional time
can be set or the timer can be turned OFF throughout
the cooking cycle.

1. With the power switch turned ON, power is

2. Time expires on ROAST timer (normal cooking).

NOTE: The buzzer continues to sound until the timer
dial is set to the OFF position or additional time is set.

Roast and Hold Cycle
NOTE: Refer to the Installation and Operation Manual

for a detailed explanation of ROAST & HOLD cooking.

1. Conditions.

1) Heat light goes out.

2) Power removed from heat relay (R3).

a. R3 normally open (N.O.) contacts

OPEN.

a) Power removed from 2nd

valve (main) on the gas valve
and gas flow to the burner
stops.

temperature control until the doors are opened or
power switch (S1) is turned to the OFF or COOL
DOWN position.

supplied to timer.

A. Set ROAST timer to desired time (normal

cooking).

B. Contacts 1 & 3 close, timer motor is

energized and timing "down" begins

A. Contacts 1 & 3 open, timer motor is de-

energize and timing stops.

B. Contacts 1 & 4 close.

1) Buzzer energized and sounds.

A. Oven connected to correct voltage.

1) L1 (HOT) to power switch (S1).

2) L2 (NEUTRAL or SECOND LINE) to
one side of the following components:
power ON light, heat light, temperature
control board terminal 9 (120VAC) or
terminal 10 (208- 240VAC), oven
cavity lights, buzzer, ROAST timer
motor (normal cooking), ROAST &
HOLD timer motor, heat relay coil (R3),
convection fan motor common (C),
transformer primary (T1), motor speed
(Hi/Low) relay coil (R1), hold relay coil
(R2) and the component cooling fan.

VC4G & VC6G SERIES FULL SIZE CONVECTION OVENS - ELECTRICAL OPERATION

B. Oven properly grounded.

C. Gas supply valve ON.

D. Gas combination control valve ON.

E. Power switch (S1) OFF.

F. Function switch (S3) set to ROAST & HOLD

cycle.

G. Oven light switch (S2) ON/OFF (position

has no affect on the function of the ROAST
& HOLD cycle).

H. Temperature control dial set to lowest

temperature (fully counterclockwise).

I. High limit switch CLOSED.

J. Cook timer (normal cooking) in the OFF

position.

K. Cook and Hold timer in the OFF position.

L. Oven doors Closed.

1) Door switch contacts CLOSED.

M. Oven cavity temperature below 140°F.

2. Set temperature control dial to desired ROAST
then Hold temperature (Roast & Hold cooking)..

3. Power switch (S1) turned ON.

A. Component cooling fan energized.

B. Power ON light (Amber) comes ON.

C. Power to one side of the following

components: Normal ROAST timer terminal
1, ROAST & HOLD timer terminal 1,
transformer primary (T1).

NOTE: Power is available to the oven light switch
(wire #20) to turn the oven cavity lights ON when the
light switch is turned ON; and power is available to the
normally open N.O. side (wire #28) of the door switch
contacts and connects power to additional
components when the door switch contacts are
CLOSED (door closed).

NOTE: Gas does not flow to the burner until the 2nd
valve (main) is energized.

2) With door switch closed, power is
applied to motor speed (Hi/Low) relay
(R1) normally open (N.O.) contacts
and hold relay (R2) common (C).

a. Motor speed relay (R1) is

energized through hold relay (R2)
normally closed contacts (N.C.).
Relay contacts (R1) change state
and the normally open (N.O.) set
of contacts close.

a) Power is connected through

the function switch (S3)
contacts and convection fan
motor is energized (fan
speed low).

NOTE: In the ROAST & HOLD cycle, the fan speed
is fixed at low.

b) When the convection fan

motor reaches operating
speed, the centrifugal switch
(N.O.) on the motor closes.

c) Power to normally open

(N.O.) side of internal relay
contacts (terminal 7) on the
temperature control board.

3) Power is also connected back through
a second set of contacts on the power
switch (S1) to terminal 8 on the
temperature control board.

a. Solid state temperature control

energized. If the oven
temperature is below set point,
the temperature control will
energize its internal relay. The
normally open (N.O.) contacts
close and apply power to the
following components:

1) Transformer (T1) energized.

a. Power (24VAC) to one side of the

following components: heat relay
(R3) normally open (N.O.)
contacts, high limit --- connected
through the normally closed
(N.C.) contacts to the 1st valve
(safety) on the dual solenoid gas
valve.

a) 1st valve (safety) on the gas

valve energized.

a) Heat light (clear) comes ON.

b) Power is connected through

the centrifugal switch
contacts on the convection
fan motor, heat relay (R3) is
energized, (R3) contacts
(N.O.) close and the heating
circuit is powered.

c) Ignition control module is

energized.

Page 59 of 88 F24682 Rev. F (1118)

VC4G & VC6G SERIES FULL SIZE CONVECTION OVENS - ELECTRICAL OPERATION

d) No ignition light (red) comes

ON, module performs a self
diagnostic test for 4 seconds,
2nd valve (main) on the gas
valve is energized. Gas
starts to flow to the burner,
sparking begins, the "no
ignition" light goes out and
burner lights. Sparking
continues for up to 7 seconds
or until a flame is
established. If a flame is
"sensed", the "no ignition"
light stays out and burner
remains lit.

If a flame is not "sensed"
after 7 seconds of sparking,
the "no ignition" light comes
back on, 2nd valve (main) on
the gas valve is de-energize
and gas flow to the burner
stops. Ignition trial cycle
repeats after a 15 second
purge between cycles for two
additional tries before
locking out. To reset after a
lockout, turn power switch
(S1) OFF then ON.

4. Oven reaches set temperature.

A. Temperature control de-energizes internal

relay and the normally open (N.O.) contacts
OPEN.

B. Heat light goes out.

C. Power removed from heat relay (R3).

1) R3 normally open (N.O.) contacts
OPEN.

a. Power removed from 2nd valve

(main) on the gas valve and gas
flow to the burner stops.

NOTE: This is considered first stage cooking in the
ROAST & HOLD cycle.

5. The oven will continue to cycle on the
temperature control until one of the following
occurs: ROAST & HOLD time (R & H cooking)
expires which allows the oven to go into Hold
mode; Power switch (S1) is turned to the OFF or
COOL DOWN position or the doors are opened.

Timer Cycle (Roast & Hold Cooking)
NOTE: The ROAST & HOLD timer operates

independently of the heating cycle until time expires.
Regulation of the oven temperature is then turned
over to the Hold thermostat until one of the following

F24682 Rev. F (1118) Page 60 of 88

occurs: ROAST & HOLD timer is turned OFF; function
switch (S3) is turned back to Normal ROAST (normal
cooking) or Power switch (S1) is turned to the OFF or
COOL DOWN position..

1. With the power switch turned ON, power is

2. Set ROAST & HOLD timer to desired time (Roast

NOTE: To Roast then Hold the cooked product at a
fixed temperature, the Roast & Hold timer must be
used and the function switch (S3) must also be set to
Roast & Hold as indicated under step1 conditions for
the Roast & Hold cycle.

3. Time expires on Roast & Hold timer.

NOTE: The Temperature control board remains
powered and the internal relay contacts remain closed
as long as oven cavity temperature is below the 175°F
minimum set point temperature of the board and
power is ON.

NOTE: When temperature is above 160°F (±12) the
hold thermostat contacts are open.

NOTE: This is considered second stage cooking in
the ROAST & HOLD cycle where the stored heat in
the oven continues to cook the product.

supplied to timer.

& Hold cooking).

A. Contacts 1 & 3 close, timer motor is

energized and timing "down" begins.

A. Contacts 1 & 3 open, timer motor is de-

energize and timing stops.

B. Contacts 1 & 4 close.

1) If the oven was heating, then the gas
burner and heat light go out; If the oven
was not heating, then the gas burner
and heat light remain out.

2) Power is connected through function
switch (S3) --- Hold relay (R2) is then
energized, R2 contacts change state
and the normally open (N.O.) contacts
close.

a. Power to one side of hold

thermostat.

3) Motor speed relay (R1) de-energized,
(R1) contacts change state and the
normally open (N.O.) contacts OPEN.

a. Convection fan motor stops and

centrifugal switch (N.O.) on motor
OPENS.

a) Heat relay (R3) de-energize,

relay (R3) contacts open and
oven heating stops.

VC4G & VC6G SERIES FULL SIZE CONVECTION OVENS - ELECTRICAL OPERATION

4. Oven temperature falls below 160°F (±12) and
hold thermostat contacts close.

A. Heat light comes ON.

B. Motor speed relay (R1) is energized, (R1)

contacts change state and the normally
open (N.O.) contacts CLOSE.

1) Convection fan motor energized (fan
speed low).

C. Power is also applied to one side of the

centrifugal switch on the convection fan
motor through the temperature control
internal relay (N.O.) contacts.

D. When the convection fan motor reaches

operating speed, the centrifugal switch on
the motor closes.

1) Heat relay (R3) is energized.

a. Heat relay (R3) contacts (N.O.)

close and

a) Ignition module is energized.

b) No ignition light (red) comes

ON, module performs a self
diagnostic test for 4 seconds,
2nd valve (main) on the gas
valve is energized. Gas
starts to flow to the burner,
sparking begins, the NO
IGNITION light goes out and
burner lights. Sparking
continues for up to 7 seconds
or until a flame is
established. If a flame is
SENSED, the NO IGNITION
light stays out and burner
remains lit.

If a flame is not SENSED
after 7 seconds of sparking,
the NO IGNITION light
comes back on, 2nd valve
(main) on the gas valve is de­energized and gas flow to the
burner stops. Ignition trial
cycle repeats after a 15
second purge between
cycles for two additional tries
before locking out. To reset
after a lockout, turn power
switch (S1) OFF then ON.

5. Oven reaches the "fixed" hold temperature and
hold thermostat opens.

B. Power removed from heat relay (R3) and

the contacts open (N.O.).

1) Ignition control module de-energized.

a. Power removed from 2nd valve

(main) on the gas valve and gas
flow to the burner stops.

C. Power is also removed from motor speed

relay (R1).

1) Convection fan motor de-energized
and fan stops rotating.

6. The oven will continue to cycle on the hold
thermostat until the ROAST & HOLD timer is
turned to the OFF position and the function
switch (S3) is change back to ROAST (normal
cooking) or the power switch (S1) is turned to the
OFF or COOL DOWN position.

Cool Down Cycle (Solid State Temperature
Control)
NOTE: The electrical sequence of operation for the

COOL DOWN cycle is written for ovens with the
ROAST & HOLD option.

1. Conditions.

A. Oven is ON.

B. Oven cavity temperature needs to be

lowered.

C. Doors are open.

1) Door switch contacts OPEN

D. Cook and Hold timer in the OFF position.

E. Cook timer (normal cooking) in the OFF

position.

F. Function switch (S3) set to either Normal

ROAST cycle or ROAST & HOLD cycle.

2. Power Switch (S1) turned to COOL DOWN.

NOTE: With door switch contacts OPEN (doors
open), the convection fan motor will still run and
continue to cool the oven. However, power would be
removed from the following components: Power ON
light (goes out), Normal ROAST timer, ROAST &
HOLD timer, transformer T1 (de-energized) and to the
component cooling fan.

A. Power to motor speed (Hi/Low) relay (R1)

normally open (N.O.) contacts and to
common (C) on hold relay (R2). Power is
then connected through hold relay (R2)
normally closed (N.C.) contacts to motor
speed (Hi/Low) relay (R1) coil.

A. Heat light goes out.

1) Motor speed (Hi/Low) relay (R1) is
energized and contacts change state.

Page 61 of 88 F24682 Rev. F (1118)

VC4G & VC6G SERIES FULL SIZE CONVECTION OVENS - ELECTRICAL OPERATION

a. Power is connected through

motor speed (Hi/Low) relay
normally open (N.O.) contacts,
through function switch (S3) to
Convection fan motor.

a) Convection fan motor

energized.

NOTE: If function switch (S3) is set to Normal ROAST
cycle, fan speed will be high; if set to ROAST & HOLD
cycle, fan speed will be low.

b) When Convection fan motor

reaches operating speed the
centrifugal switch on the
motor closes but no power is
available for connection to
other components.

B. Power to one side of the hold thermostat

contacts but is not transferred to other
components due to oven cavity temperature
above 160°F (thermostat OPEN).

C. Power to terminal 7 on the solid state

temperature control but is not transferred to
other components due to temperature
control not being powered.

3. If door switch is CLOSED (doors closed), power
is supplied to one side of the following
components: Power ON light (Amber), oven light
switch (S2), Normal ROAST timer terminal 1,
ROAST & HOLD timer terminal 1, transformer
primary (T1) and component cooling fan.

A. Power ON light (Amber) comes ON.

VC4GC, VC6GC (Roast & Hold Standard on
Computer Model)

Schematic diagram 10437 will be used to explain the
electrical sequence of operation for both the ROAST
cycle (normal cooking) and the ROAST & HOLD cycle.

Roast Cycle (Normal Cooking)

1. Conditions.

A. Oven connected to correct voltage.

1) L1 (HOT) to power switch (S1).

2) L2 (NEUTRAL or SECOND LINE) to
one side of the following components:
oven cavity lights, convection fan
motor common (C), transformer
primary (T1), component cooling fan
and the heat relay coil (R1).

B. Oven properly grounded.

1) Ground (GND) to one side of the
following components: computer
control case, "no ignition" light,
transformer secondary (T1), ignition
control module, the 1st valve (safety)
and 2nd valve (main) on the dual
solenoid gas valve and computer
control pin 9 (C3-9).

C. Gas supply valve ON.

D. Gas combination control valve ON.

E. Power switch (S1) OFF.

F. Computer control is setup properly and

ready to use.

B. Transformer (T1) energized.

1) Power (24VAC) to one side of the
following components: heat relay (R3)
normally open (N.O.) contacts, high
limit --- connected through the normally
closed (N.C.) contacts to the 1st valve
(safety) on the dual solenoid gas valve.

a. 1st valve (safety) on the gas valve

energized.

NOTE: Gas does not flow to the burner until the 2nd
valve (main) is energized.

C. Component cooling fan.

4. The oven will remain in this condition until the
power switch (S1) is turned to the OFF or ON
position.

F24682 Rev. F (1118) Page 62 of 88

2. Power switch (S1) turned ON.

NOTE: Power at pin 3 is not transferred to other
components until computer control is energized and
operating conditions are met.

G. Oven light switch (S2) ON/OFF (position

has no affect on the function of the ROAST
cycle).

H. High limit switch CLOSED.

I. Oven doors Closed.

1) Door switch contacts CLOSED.

J. Oven cavity temperature below 140°F.

A. Power (120VAC) to computer control pin 3

(C3-3).

B. Power is available to the oven light switch

(S2).

VC4G & VC6G SERIES FULL SIZE CONVECTION OVENS - ELECTRICAL OPERATION

C. Power to terminal 1 on solid state relay 1

(SSR1 -load side) and solid state relay 2
(SSR2 -load side).

D. Component cooling fan energized.

E. Transformer (T1) is energized.

1) Power (24VAC) to one side of the
following components: heat relay (R1)
normally open (N.O.) contacts, high
limit --- connected through the normally
closed (N.C.) contacts to the 1st valve
(safety) on the dual solenoid gas valve.

a. 1st valve (safety) on the gas valve

energized.

NOTE: Gas does not flow to the burner until the 2nd
valve (main) is energized.

2) Power (24VAC) to the oven computer
control.

a. Control is energized and performs

a power ON self test before
energizing outputs.

NOTE: If the control passes self test, then the outputs
are energized and operation sequence continues. If
control does not pass self test then the corresponding
error code is displayed.

b. Computer control senses oven

cavity temperature.

a) With the oven cavity

temperature below set point,
the controls 120VAC output
from pin C3-2 is activated
and power is connected to
the common (C) side of the
centrifugal switch contacts
on the convection fan motor.

NOTE: The set point temperature of the computer
control will be the last temperature that was set.

NOTE: Power is not applied to the heat relay coil (R1)
until the centrifugal switch contacts on the convection
fan motor close.

c. The controls 5VDC output from

pins C2-2 (-) and C2-8 (+) is
activated and SSR1 relay is
energized.

a) Convection fan motor is

energized (fan speed hi).

b) When the convection fan

motor reaches operating
speed, the centrifugal switch
(N.O.) on the motor closes.

3) With the 120VAC output from the
control activated and the centrifugal
switch on the convection fan motor
closed, power is applied to the heat
relay coil (R1).

a. Heat relay coil (R1) is energized,

(R1) contacts (N.O.) close and the
heating circuit is powered.

b. Oven "Heat Light" on the control

comes ON.

c. Ignition control module is

energized.

a) No ignition light (red) comes

ON, module performs a self
diagnostic test for 4 seconds,
2nd valve (main) on the gas
valve is energized. Gas
starts to flow to the burner,
sparking begins, the NO
IGNITION light goes out and
burner lights. Sparking
continues for up to 7 seconds
or until a flame is
established. If a flame is
SENSED, the NO IGNITION
light stays out and burner
remains lit.

If a flame is not SENSED
after 7 seconds of sparking,
the NO IGNITION light
comes back on, 2nd valve
(main) on the gas valve is de­energized and gas flow to the
burner stops. Ignition trial
cycle repeats after a 15
second purge between
cycles for two additional tries
before locking out. To reset
after a lockout, turn power
switch (S1) OFF then ON.

3. Oven reaches set point temperature.

A. Computer control de-activates the 120VAC

output to heat relay (R1).

1) Heat relay (R1) de-energized and the
normally open (N.O.) contacts OPEN.

a. Power removed from ignition

control module.

a) The 2nd valve (main) on the

gas valve is de-energized
and gas flow to the burner
stops.

Page 63 of 88 F24682 Rev. F (1118)

VC4G & VC6G SERIES FULL SIZE CONVECTION OVENS - ELECTRICAL OPERATION

B. Oven "Heat Light" on the control goes out.

C. Oven "Ready Light" on the control comes

ON.

D. Electronic beeper sounds momentarily.

4. The oven will continue to cycle on the computer
control until the doors are opened or power
switch (S1) is turned to the OFF or COOL DOWN
position.

Temperature and Time Cycle (Cooking)
NOTE: The computers internal COOK timer operates

independently of the heating cycle. Additional time
can be set or the timer can be stopped and restarted
throughout the cooking cycle. Refer to the Instructions
Manual for specific operating instructions of the oven
Computer Control.

Roast and Hold Cycle
NOTE: For a detailed explanation of the ROAST &

HOLD mode, refer to the Instructions Manual as
outlined under SETTING THE OVEN FOR ROAST &
HOLD and ROAST & HOLD OPERATION. In ROAST
& HOLD mode, the operation of the computer control
is identical to the normal Cook Cycle with these
exceptions:

1. Oven ROAST & HOLD light on the control comes
ON.

2. Convection fan speed changes from High to Low.

A. The computer control 5VDC output from

pins C2-2 (-) and C2-8 (+) is de-activated
and SSR1 relay is de-energized.

1) Power (120VAC) is removed from
convection fan motor high speed
terminal.

B. The computer control 5VDC output from

pins C2-1 (-) and C2-8 (+) is activated and
SSR2 relay is energized.

1)
Power (120VAC) is applied to the

convection fan motor low speed
terminal.

5. After the oven temperature drops below 150°F,
the heat comes back ON and cycles as needed,
to maintain the "Hold" temperature of 150°F.

A. Convection fan motor energized.

6. The oven continues to cycle in this manner until
one of the following occurs:

A. The ROAST & HOLD mode is turned OFF.

B. Power switch (S1) is turned to the OFF or

COOL DOWN position.

Cool Down Cycle (Computer Control Model)

1. Conditions.

A. Oven is ON.

B. Oven cavity temperature needs to be

lowered.

C. Doors are open.

1) Door switch contacts OPEN.

D. Power switch (S1) set to either ON or OFF.

2. Power Switch (S1) turned to COOL DOWN.

NOTE: With door switch contacts OPEN (doors
open), the convection fan motor will still run and
continue to cool the oven.

A. Power is connected through power switch

(S1) to the convection fan motor high speed
terminal.

1) Convection fan motor energized.

2) When Convection fan motor reaches
operating speed the centrifugal switch
on the motor closes but no power is
available for connection to other
components.

3) The oven will continue to operate in
COOL DOWN mode until the power
switch (S1) is turned to the OFF or ON
position.

3. At the end of the ROAST time, the electronic
beeper sounds momentarily to indicate the end
of first stage cooking (oven operates normally at
the temperature and time selected until time
expires).

4. The display flashes HOLD as the oven enters
HOLD mode. This is also considered second
stage cooking (oven heating stops but product
continues to cook on residual heat).

A. Convection fan motor is de-energized.

F24682 Rev. F (1118) Page 64 of 88

VC4G & VC6G SERIES FULL SIZE CONVECTION OVENS - SCHEMATICS

SCHEMATICS

VC4GS, VC6GS Mechanical (KX) Controls

Page 65 of 88 F24682 Rev. F (1118)

VC4G & VC6G SERIES FULL SIZE CONVECTION OVENS - SCHEMATICS

VC4GS, VC6GS Mechanical (KX) Controls, Roast & Hold Option

F24682 Rev. F (1118) Page 66 of 88

VC4G & VC6G SERIES FULL SIZE CONVECTION OVENS - SCHEMATICS

VC4GD, VC6GD Solid State Temperature Control

UP TO SERIAL NUMBER 481907145

Page 67 of 88 F24682 Rev. F (1118)

VC4G & VC6G SERIES FULL SIZE CONVECTION OVENS - SCHEMATICS

STARTING AT SERIAL NUMBER 481907146

F24682 Rev. F (1118) Page 68 of 88

VC4G & VC6G SERIES FULL SIZE CONVECTION OVENS - SCHEMATICS

VC4GD, VC6GD Solid State Temperature Control, Roast & Hold Option

Page 69 of 88 F24682 Rev. F (1118)

VC4G & VC6G SERIES FULL SIZE CONVECTION OVENS - SCHEMATICS

VC4GC, VC6GC Computer Control (Roast & Hold Standard)

UP TO SERIAL NUMBER 481907145

F24682 Rev. F (1118) Page 70 of 88

VC4G & VC6G SERIES FULL SIZE CONVECTION OVENS - SCHEMATICS

STARTING AT SERIAL NUMBER 481907146

Page 71 of 88 F24682 Rev. F (1118)

VC4G & VC6G SERIES FULL SIZE CONVECTION OVENS - WIRING DIAGRAMS

WIRING DIAGRAMS

VC4GS, VC6GS Mechanical (KX) Controls

Fig. 113

F24682 Rev. F (1118) Page 72 of 88

VC4G & VC6G SERIES FULL SIZE CONVECTION OVENS - WIRING DIAGRAMS

Fig. 114

Page 73 of 88 F24682 Rev. F (1118)

VC4G & VC6G SERIES FULL SIZE CONVECTION OVENS - WIRING DIAGRAMS

VC4GS, VC6GS Mechanical (KX) Controls, Roast & Hold Option

Fig. 115

F24682 Rev. F (1118) Page 74 of 88

VC4G & VC6G SERIES FULL SIZE CONVECTION OVENS - WIRING DIAGRAMS

Fig. 116

Page 75 of 88 F24682 Rev. F (1118)

VC4G & VC6G SERIES FULL SIZE CONVECTION OVENS - WIRING DIAGRAMS

VC4GD, VC6GD Solid State Temperature Control

Fig. 117

F24682 Rev. F (1118) Page 76 of 88

VC4G & VC6G SERIES FULL SIZE CONVECTION OVENS - WIRING DIAGRAMS

Fig. 118

Page 77 of 88 F24682 Rev. F (1118)

VC4G & VC6G SERIES FULL SIZE CONVECTION OVENS - WIRING DIAGRAMS

STARTING AT SERIAL NUMBER 481907146

F24682 Rev. F (1118) Page 78 of 88

VC4G & VC6G SERIES FULL SIZE CONVECTION OVENS - WIRING DIAGRAMS

VC4GD, VC6GD Solid State Temperature Control, Roast & Hold Option

Fig. 120

Page 79 of 88 F24682 Rev. F (1118)

VC4G & VC6G SERIES FULL SIZE CONVECTION OVENS - WIRING DIAGRAMS

Fig. 121

F24682 Rev. F (1118) Page 80 of 88

VC4G & VC6G SERIES FULL SIZE CONVECTION OVENS - WIRING DIAGRAMS

VC4GC, VC6GC Computer Control (Roast & Hold Standard)

Fig. 122

Page 81 of 88 F24682 Rev. F (1118)

VC4G & VC6G SERIES FULL SIZE CONVECTION OVENS - WIRING DIAGRAMS

Fig. 123

F24682 Rev. F (1118) Page 82 of 88

VC4G & VC6G SERIES FULL SIZE CONVECTION OVENS - WIRING DIAGRAMS

STARTING AT SERIAL NUMBER 481907146

Page 83 of 88 F24682 Rev. F (1118)

VC4G & VC6G SERIES FULL SIZE CONVECTION OVENS - TROUBLESHOOTING

TROUBLESHOOTING

Certain procedures in this section require electrical test or measurements while power is
applied to the machine. Exercise extreme caution at all times and follow Arc Flash procedures.
If test points are not easily accessible, disconnect power and follow Lockout/Tagout
procedures, attach test equipment and reapply power to test.

ALL MODELS

SYMPTOMS POSSIBLE CAUSES

1. Line voltage.

2. Power switch (S1) malfunction.
Blower motor doesn’t run with 1S in “Cool Down” or “On”
position.

3. Switch (S3) malfunction.

4. Interconnecting wiring malfunction.

Blower motor doesn’t run in “On” position. “Cool Down”
functions OK.

Blower motor doesn’t run in “Cool Down” position. Runs
OK in “On” position.

Gas does not ignite; No spark; No Ignition Light ON.

Sparks but gas does not ignite.

5. Motor inoperable.

1. Door switch malfunction.

2. Power switch contacts inoperative.

3. Interconnecting wiring malfunction.

1. Power switch malfunction.

2. Interconnecting wiring malfunction.

1. Shorted electrode on ignitor/flame sense.

2. Ignitor cable (high voltage) OPEN.

3. Heat relay (R3) malfunction.

4. Transformer (T1) inoperative.

5. High limit thermostat open.

6. Interconnecting wiring malfunction.

7. Ignition Module malfunction.

1. Gas solenoid valve OFF or inoperative.

2. Manual gas valve CLOSED.

3. Gas supply OFF or Insufficient gas pressure.

4. Interconnecting wiring malfunction.

5. Ignition Module malfunction.

F24682 Rev. F (1118) Page 84 of 88

VC4G & VC6G SERIES FULL SIZE CONVECTION OVENS - TROUBLESHOOTING

SYMPTOMS POSSIBLE CAUSES

1. Igniter lead connections malfunction.

2. Ignitor ground inoperative.

3. Ignitor/flame sense malfunction.

Gas ignites but will not maintain flame.

Excessive or low heat.

4. Insufficient gas pressure.

5. Snorkel vent plugged, obstructed or missing.

6. Incorrect polarity from transformer (T1) to Ignition

module.

1. Temperature probe malfunction on models

HGC5/5X. (Thermostat malfunction on models
DGC5)

2. Temperature control board malfunction.

3. Gas pressure Insufficient.

4. Gas orifice plugged or obstructed.

1. Interconnecting wiring malfunction.

Mechanical Timer inoperative or not functioning properly.

Cook mode OK, no Hold mode. (Cook & Hold models
only).

Component cooling Fan does not run.

Uneven Cooking.

Intermittent problems.

No power to temperature control.

2. Line voltage incorrect.

3. Timer malfunction.

1. Cook and Hold switch (S3) malfunction.

2. R2 hold relay malfunction.

3. Cook & Hold timer malfunction.

4. Interconnecting wiring malfunction.

1. Motor inoperable.

2. Interconnecting wiring malfunction.

1. Convection Fan motor speed/direction.

2. Poor combustion.

A. Gas pressure incorrect.

B. Exhaust vent plugged or obstructed.

C. Snorkel Vent plugged or obstructed.

3. Air flow Baffles missing or damaged.

1. High ambient temperatures.

2. Wiring connections loose.

3. Cooling fan malfunction.

1. Power switch (S1) in “Cool Down”.

2. Door or door switch open.

IGNITION MODULE DIAGNOSTICS

Page 85 of 88 F24682 Rev. F (1118)

VC4G & VC6G SERIES FULL SIZE CONVECTION OVENS - TROUBLESHOOTING

NUMBER OF LED FLASHES INDICATES POSSIBLE CAUSE

1. Main gas valve stuck open,
burner on with no call for heat
from the temperature control
system. Replace main gas

2 Flashes Burner flame with no call for heat.

3 Flashes Ignition system has locked out.

valve.

2. Check flame sensor and sensor
wire.

3. Ignition module malfunction.

1. Ignition module could not
“Prove” flame after three tries for
ignition within the lockout time
timing provided.

A. Check for gas supply to

burner.

B. Check for spark to ignition

electrode.

1) Check spark gap (gap
should be 1/8").

4 Flashes Internal board problem.

COMPUTER CONTROL MODELS ONLY

SYMPTOM POSSIBLE CAUSES

1. High limit switch open.

Oven does not heat.

2. Probe malfunction.

C. Check for flame current in

flame sense wire (0.000001
Amp Min. DC) using FC
designated terminals.

1) Check burner
adjustment (air/gas).

NOTE: If A thru C check
out, replace ignition
module.

1. Ignition module malfunction.
Remove power from “R” terminal
for five seconds then reconnect.
If fault remains, replace ignition
module.

3. Control malfunction.

High limit thermostat shutting off gas burner.

F24682 Rev. F (1118) Page 86 of 88

1. Probe malfunction.

2. Control malfunction.

VC4G & VC6G SERIES FULL SIZE CONVECTION OVENS - TROUBLESHOOTING

SYMPTOM POSSIBLE CAUSES

1. Probe malfunction.

2. Control range high (rH1) setting to low. SETUP

Oven not hot enough.

Error Codes

In the display window, the error code will alternate between the code and the oven cavity temperature or dashes if
the oven is calling for heat (heat light on). When the condition causing the error is resolved, normal oven operation
can resume.

NOTE: To check a "Setup Parameter" and its corresponding "Data Value", see "SETUP MODE" under COMPUTER
CONTROL (VC4GC/6GC).

NOTE: If the cause of the error is not apparent, check for these conditions as they may also cause errors to occur:
Electrical noise or a noise event, excess environmental moisture or temperature, or vibration.

CODE & PROBLEM PROBABLE CAUSE SOLUTION

Er01 - ROM checksum error Internal ROM malfunction Cycle power

Er02 - RAM checksum error Internal RAM malfunction Cycle power

Er03 - Ambient sensor error Ambient temperature is below 32°F

Er04 - Configuration error Microprocessor malfunction Cycle power

Er05 - EPROM error Power loss while storing data Cycle power

• Incorrect sensor type

Er06 - Zone 1 A/D underflow error

Er07 - Zone 1 A/D overflow error Open sensor

Er10 - Stack overflow error Microprocessor malfunction

• Measuring temperature outside
the sensor range

MODE under COMPUTER CONTROL (VC4GD,
VC6GD).

3. Control malfunction.

Check ambient temperature at the
control.

• Check the InP1 setup
parameter. Verify it matches
your sensor.

• Check sensor and connections
for a reversed or open sensor. If
the condition causing the error is
resolved, the error will clear.

• Check the InP1 setup
parameter. Verify it matches
your sensor.

• Check sensor and connections
for a reversed or open sensor. If
the condition causing the error is
resolved, the error will clear.

• Cycle power

• Check sensor and connections
for a reversed or open sensor

Page 87 of 88 F24682 Rev. F (1118)

VC4G & VC6G SERIES FULL SIZE CONVECTION OVENS - TROUBLESHOOTING

CODE & PROBLEM PROBABLE CAUSE SOLUTION

• Check the InP1 setup
parameter. Verify it matches
your sensor.

Er11 - Open sensor error Open sensor

• Incorrect sensor type

Er12 - Shorted sensor

• Measuring temperature outside
the sensor range

• Check sensor and connections
for a reversed or open sensor. If
the condition causing the error is
resolved, the error will clear.

• Check the InP1 setup
parameter. Verify it matches
your sensor.

• Check sensor and connections
for a reversed or open sensor. If
the condition causing the error is
resolved, the error will clear.

F24682 Rev. F (1118) Page 88 of 88