Thermador PRG486JDG/01 User manual

Service Manual for the Thermador Pro Grand Next Generation 48-Inch Natural Gas and LP Gas Ranges, Models: PRG486JDG/01, PRL486JDG/01
58300000159722_ARA_EN_DPage 2 of 92
TABLE OF CONTENTS
1General .................................................................................................... 5
1.1 Technical Documents to Read Prior to Servicing.......................................... 5
1.2 Data Rating Plate.......................................................................................... 5
1.3 Wiring Diagram ............................................................................................. 6
1.4 Recommended Tools and Supplies .............................................................. 6
1.5 Important Safety Information......................................................................... 7
1.5.1 Safety Symbols Used In This Manual.................................................... 7
1.5.2 Safety Precautions to Know Prior to Servicing....................................... 7
2Operation and Controls ....................................................................... 10
2.1 Knobs and Controls..................................................................................... 10
2.1.1 Standard Burner Knob......................................................................... 10
2.1.2 ExtraLow (XLO) and ExtraHi (XHI) Burner Knobs................................ 10
2.1.3 Griddle / Grill Control Knob.................................................................. 10
2.1.4 Temperature / Function Selector Knob for Large Oven ....................... 10
2.1.5 Temperature / Function Selector Knob for Small Oven........................ 11
2.1.6 Oven Light and Panel Light Switches .................................................. 11
2.2 LED Indicators............................................................................................. 11
2.3 Automatic Re-Ignition.................................................................................. 11
2.4 Operation during a Power Outage............................................................... 11
2.5 Rangetop Burner Assembly and Maintop Components .............................. 11
3Testing, Adjusting, and Troubleshooting Rangetop Burners and
Ignition................................................................................................... 12
3.1 Before Testing............................................................................................. 12
3.2 Rangetop Burner Characteristics................................................................ 12
3.3 Rangetop Flame Characteristics................................................................. 13
3.4 Testing Ignition for Burners......................................................................... 14
3.4.1 Time to Ignite....................................................................................... 14
3.4.2 Testing Ignition for Standard Burner Settings (HI, MEDIUM, SIM)....... 14
3.4.3 Testing Ignition for XLO Burner Settings.............................................. 14
3.4.4 Testing Broil Burner Ignition................................................................. 14
3.4.5 Testing Bake Burner Ignition................................................................ 14
3.5 Adjusting Bake Burner Flame with the Air Shutter...................................... 14
3.6 Adjusting Rangetop Burner Valves Manually.............................................. 15
3.6.1 Special Tools Needed.......................................................................... 15
3.6.2 Adjusting the Bypass Screws............................................................... 16
3.7 Troubleshooting Burners, Flame, and Ignition ............................................ 16
3.7.1 Burner and Flame Diagnostics for Rangetop Burners.......................... 16
3.7.2 Ignition Diagnostics for Rangetop Burners........................................... 16
4Diagnosing Hot Surface Igniters, Griddle / Grill Element, Oven
Lights, Temp Sensors.......................................................................... 18
4.1 HSI and Element Diagnostics ..................................................................... 18
4.1.1 Cycle/Circuit Specification.................................................................... 18
4.1.2 Safety Practices for HSI and Element Diagnostics .............................. 18
4.1.3 HSI and Element Diagnostic Tips ........................................................ 18
4.2 Oven Light Diagnostics............................................................................... 18
4.3 Oven Temperature Sensor Diagnostics...................................................... 20
4.3.1 Resistance and Temperature Values for the Oven Temperature Sensor
20
5Fault Messages..................................................................................... 21
6Service and Repair ............................................................................... 22
6.1 Preparing the Range for Servicing.............................................................. 22
6.2 Component Removal Videos ...................................................................... 22
6.3 Accessing Components under the Maintop................................................. 22
6.3.1 Removing Knobs, Grates, Rangetop Burner Assemblies, Maintops,
Heat Shields, Burner Support Rails ..................................................... 22

Service Manual for the Thermador Pro Grand Next Generation 48-Inch Natural Gas and LP Gas Ranges, Models: PRG486JDG/01, PRL486JDG/01
58300000159722_ARA_EN_DPage 3 of 92
6.3.2 Removing the Maintops....................................................................... 24
6.3.3 Removing the Heat Shields.................................................................. 25
6.3.4 Removing the Burner Support Rails..................................................... 25
6.4 Griddle / Grill Removal and Replacement................................................... 27
6.5 Side Panel Removal and Replacement....................................................... 29
6.6 Control Panel Removal and Replacement.................................................. 32
6.7 Removal and Replacement of Top-Accessible Components...................... 34
6.7.1 Jet Holder Assembly Removal and Replacement................................ 34
6.7.2 Standard Valve Removal and Replacement........................................ 36
6.7.3 Microswitch Removal and Replacement.............................................. 37
6.7.4 Solenoid Valve Removal and Replacement......................................... 37
6.7.5 XLO Valve Removal and Replacement................................................ 39
6.7.6 Potentiometer Removal and Replacement .......................................... 40
6.7.7 Manifold for Rangetop Burners – Removal and Replacement............. 40
6.7.8 Manifold for Bake and Broil Burners – Removal and Replacement ..... 43
6.7.9 Regulator Removal and Replacement................................................. 45
6.7.10 Bi-Metal Gas Valves – Removal and Replacement ............................. 46
6.7.11 Oven Lamp Transformer Removal and Replacement.......................... 47
6.7.12 Selector Switch for Oven Function and Oven Temperature – Removal
and Replacement................................................................................. 48
6.7.13 Oven Temperature Gauge Removal and Replacement....................... 49
6.7.14 Control Boards for Large and Small Ovens – Removal and
Replacement........................................................................................ 50
6.7.15 Simmer Control Board Removal and Replacement ............................. 51
6.7.16 LED Indicator Removal and Replacement........................................... 52
6.7.17 Lighting Bar for Control Panel – Removal and Replacement............... 53
6.7.18 Ignition (Spark) Module Removal and Replacement............................ 54
6.7.19 Door Latch Removal and Replacement............................................... 55
6.7.20 Plunger Switch Removal and Replacement......................................... 57
6.7.21 Griddle / Grill Thermostat Removal and Replacement......................... 58
6.7.22 Oven Display Module and Light Switch – Removal and Replacement. 59
6.8 Removal and Replacement of Back-Accessible Components .................... 60
6.8.1 Backguard Removal and Replacement................................................ 61
6.8.2 Back Panel for Small Oven – Removal and Replacement................... 62
6.8.3 Back Panel for Large Oven – Removal and Replacement................... 63
6.8.4 Terminal Block and Power Cord – Removal and Replacement ........... 63
6.8.5 Electrical Wiring Connections at the Terminal Block............................ 64
6.8.6 Cooling Fan Removal and Replacement ............................................. 64
6.9 Removal and Replacement of Front-Accessible Components.................... 65
6.9.1 Oven Temperature Sensor for Large and Small Ovens – Removal and
Replacement........................................................................................ 65
6.9.2 Meat Probe Receptacle Components – Removal and Replacement... 66
6.9.3 Rack Support Removal and Replacement........................................... 67
6.9.3.1 Oven Lamp Assembly and Bulb – Removal and Replacement..... 68
6.9.3.2 Removing the Bulb........................................................................ 69
6.9.3.3 Removing the Lamp Assembly...................................................... 69
6.9.4 Oven Door Removal, Installation, and Alignment................................. 70
6.9.4.1 Removing the Door ....................................................................... 70
6.9.4.2 Installing the Door ......................................................................... 71
6.9.4.3 Aligning the Door........................................................................... 72
6.9.5 Convection Components – Removal and Replacement....................... 72
6.9.6 Broil Burner Components – Removal and Replacement...................... 75
6.9.6.1 Hot Surface Igniter for Broil Burner – Removal and Replacement 75
6.9.6.2 Broil Burner Removal and Replacement....................................... 77
6.9.7 Bake Burner Components (Large Oven) – Removal and Replacement78
6.9.7.1 Bake Burner HSI for Large Oven – Removal and Replacement ... 79
6.9.7.2 Bake Burner for Large Oven – Removal and Replacement .......... 81

Service Manual for the Thermador Pro Grand Next Generation 48-Inch Natural Gas and LP Gas Ranges, Models: PRG486JDG/01, PRL486JDG/01
58300000159722_ARA_EN_DPage 4 of 92
6.9.7.3 Bake Burner Orifice and Elbow Connector for Large Oven –
Removal and Replacement........................................................... 82
6.9.8 Bake Burner Components (Small Oven) – Removal and Replacement84
6.9.8.1 Bake Burner HSI for Small Oven – Removal and Replacement.... 84
6.9.8.2 Bake Burner for Small Oven – Removal and Replacement........... 86
6.9.8.3 Bake Burner Orifice and Elbow Connector for Small Oven –
Removal and Replacement........................................................... 87
6.9.9 Door Interior Cleaning.......................................................................... 88
6.9.10 Oven Door Components – Removal and Replacement....................... 89
6.9.11 Door Gasket Removal and Replacement............................................. 90
6.9.12 Kick Panel Removal and Replacement................................................ 91
7Before Returning Appliance to Service.............................................. 91
8Clean-Up................................................................................................ 92
9Additional Resources........................................................................... 92
9.1 QuickFinder................................................................................................. 92
9.2 Technical Support....................................................................................... 92

Service Manual for the Thermador Pro Grand Next Generation 48-Inch Natural Gas and LP Gas Ranges, Models: PRG486JDG/01, PRL486JDG/01
58300000159722_ARA_EN_DPage 5 of 92
1 GENERAL
This manual provides servicing instructions for the following
Thermador Pro Grand Next Generation (PGNG) liquid propane (LP)
ranges.
PRG486JDG/01
PRL486JDG/01
Due to the complexity and the risk of high-voltage electrical shock,
customers should not service their appliances.
The information provided in this document is intended for trained,
qualified personnel only. The proper function and the safety of the
appliance can be affected by an improper repair, and even serious
threats to life or physical condition may arise. BSH Home Appliances
Corporation is not liable for damages caused by improper repairs
performed by unauthorized parties. Local codes and standards apply
and must be observed.
For authorized servicers, additional assistance is available by
contacting our Technical Support Team at [phone].
1.1 Technical Documents to Read Prior to Servicing
Before you start servicing, check QuickFinder for all documents and
information associated with this specific appliance and/or parts.
1.2 Data Rating Plate
The data rating plate shows the model, serial, and FD number. It is
located at the right side panel (see Figure 1), and is pulled out by the
tab. The information on the data rating plate is required when calling
for technical or customer service.
The first two digits of the FD number indicate the year the appliance
was produced. To get the year, add 20 to the first two digits (for
example, an FD number beginning with 87 was produced in 2007; a
number that begins with 88 was produced in 2008). The last 2 digits of
the FD number indicate the month the product was produced (for
example, 06 indicates the appliance was produced in June).
Figure 1: Data Rating Plate

Service Manual for the Thermador Pro Grand Next Generation 48-Inch Natural Gas and LP Gas Ranges, Models: PRG486JDG/01, PRL486JDG/01
58300000159722_ARA_EN_DPage 6 of 92
1.3 Wiring Diagram
The wiring diagram is located on the back side of the kick panel
(see Figure 2).
Figure 2: Wiring Diagram Location
1
Kick panel (wiring diagram located on back side)
1.4 Recommended Tools and Supplies
The following are recommended to use when servicing this appliance:
mCaution
Power Drivers
If using a power driver, set the clutch to the lowest setting
üFlat blade screwdrivers: large, small
üPrecision flat-blade screwdriver with a high-strength blade,
1/8 inch (3.0 mm) wide, .020-inch (0.50 mm) thickness tip
üDrivers: T-10, T-20, T-27, T-30
ü2 foot long rachet extension
üRachet with 6 inch long (min.) swivel head extension
ü6 inch long (min.) flex extension
ü5/16 inch deep-well socket
ü1/4 inch nut driver
üAdjustable wrenches (2)
üStrap wrench
üOpen-end wrench sizes: 1/4 inch, 9 mm, 11 mm, 1/2 inch,
9/16 inch, 5/8 inch, 3/4 inch, 5/16 inch
üPipe wrench
üNeedle-nose pliers
üClean putty knife
üProtective gloves
üGas leak test equipment
üPipe sealant
üSmall mirror
üAir lifter / air dolly
üFloor protection
üProtective eye wear (such as glasses, goggles)
üFlashlight
üAmp meter
üThermometer with thermocouple leads
üMultimeter
üClean, non-abrasive cleaning cloth & flexible brush

Service Manual for the Thermador Pro Grand Next Generation 48-Inch Natural Gas and LP Gas Ranges, Models: PRG486JDG/01, PRL486JDG/01
58300000159722_ARA_EN_DPage 7 of 92
1.5 Important Safety Information
Before starting to service an appliance, familiarize yourself with all
safety information and precautions contained in this manual.
1.5.1 Safety Symbols Used In This Manual
Warnings alert you to dangers that may result in bodily injury or death.
mCaution
Cautions alert you to actions that may result in damage to the product,
or property.
1.5.2 Safety Precautions to Know Prior to Servicing
Before You Start Servicing the Appliance
Before disassembly, removal or installation of any component, do the
following:
■Turn off electrical power by removing the power cord from the
electrical outlet, and putting the circuit breaker in the OFF position
(or removing the fuse)
■Turn off the gas supply to the appliance
■Make sure the range and components are cool before removing or
servicing them
■Wear protective clothes: long sleeves, gloves, safety glasses
Replacement Parts
Use only authorized replacement parts for this appliance. Use of
substitutions may defeat compliance with safety standards set for
home appliances, will void the warranty, and may create safety
hazards resulting in bodily injury, death, or damage.
Fire / Explosion Hazards
■Make sure the gas valve at the wall is closed before removing and
installing any gas components.
■Do not store or use any flammable vapors, liquids, or combustible
materials in the vicinity of this appliance.
■Do not use water on grease fires. Turn appliance off and smother
the fire with baking soda or use a dry chemical or foam-type
extinguisher.
Griddle / Grill Hazard
The griddle / grill plate must always be correctly in place when it’s on.
What to Do If You Smell Gas
■Turn off the electrical power supply (at the circuit breaker), but do
not touch any electrical switch on the appliance
■Shut off gas supply to the appliance
■Do not try to light this or any other appliance
■Do not create or use an open flame or spark
■Do not use any phone or cell phone in the building
■Installation and service must be performed by a qualified installer,
service agency, or the gas supplier.
Testing for Gas Leaks
■Do not ever use a flame to test for gas leaks, as doing so may
result in explosion, injury, death, and/or damage to the appliance
and property.

Service Manual for the Thermador Pro Grand Next Generation 48-Inch Natural Gas and LP Gas Ranges, Models: PRG486JDG/01, PRL486JDG/01
58300000159722_ARA_EN_DPage 8 of 92
■With electrical power off, carefully check for gas leaks at each gas
component that was removed, replaced, or otherwise serviced
using a gas leak detector (electronic leak detectors are highly
recommended) or bubble test. The only exceptions that may
require the electrical power on are for XLO valves and bi-metal
gas valves. For these components, use extreme caution when
performing gas leak testing with electrical power on.
Electrical Hazards
■Before servicing the appliance, remove electrical power by
disconnecting the power cord from the wall receptacle, by shutting
off the circuit breaker, or by disconnecting the proper fuse.
■If tests have to be conducted while the appliance is live, always
use a residual-current-operated circuit-breaker. The protective
conductor connection must not exceed the recommended values.
■When repairs are complete, perform a function test in accordance
with the appropriate regulations.
■Do not under any circumstances cut or remove the separate
ground wire or the third (ground) prong from the power cord plug.
■Improper grounding or reverse polarization will cause malfunction
(such as continuous sparking of the igniters), which can damage
the appliance and create an electrical shock hazard. Make sure
the circuit is properly grounded and polarized in accordance with
applicable local codes and ordinances. Receptacle replacement
shall be in accordance with the National Electric Code.
Hot Surfaces
To avoid burns and injury, do not handle components and surfaces
that are hot, such as the rangetop burner assemblies, maintop,
griddle/grill, gas burners, electric elements, hot surface igniters, heat
deflector, and interior oven surfaces, or the exterior area immediately
surrounding the door.
Sharp Components
This appliance has sheet metal and other components which often
have sharp edges. When working on this appliance, avoid cutting
yourself and other injury by handling these parts with care and using
adequate protective measures, such as gloves.
In Case of Power Outage
■When there is a removal of electrical power, the XLO / XHI
burners and griddle/grill cannot be used. Do not attempt to light
them manually during a power outage.
■If for any reason a control knob is on when there is any failure or
removal of electrical power from the appliance (such as a power
outage), immediately turn all control knob(s) to the OFF position.
■Ventilate well by opening a door or window, and wait at least 5
minutes for all the gas to dissipate.
■If you smell gas, refer to the applicable safety precautions stated
in this manual.
Clean-up Hazards
■Don’t allow any cleaning or polishing solutions/compounds,
disinfectants or bleaches to remain in contact with the stainless
steel surfaces for long periods, or after clean-up. These may
contain chemicals or materials which could release harmful
inhalants and can damage the appliance. After cleaning or
polishing, always rinse the cleaning/polishing materials with clear
water and wipe dry with a clean soft, non-abrasive cloth.
■Never use bleach-containing or chlorinated cleaners, as they act
as oxidizers on metal surfaces

Service Manual for the Thermador Pro Grand Next Generation 48-Inch Natural Gas and LP Gas Ranges, Models: PRG486JDG/01, PRL486JDG/01
58300000159722_ARA_EN_DPage 9 of 92
■Clean the range with caution. Do not use flammable cleaners to
clean the range. Avoid steam burns; do not use a wet sponge or
cloth to clean the range while it is hot. Do not use any type of
aerosol cleaner on or around the rangetop when hot. Some
cleaners produce noxious fumes if applied to a hot surface. Follow
directions provided by the cleaner manufacturer.
Fiberglass Insulation
Wear gloves when handling fiberglass insulation.
Oven Door, Oven Accessories and Oven Gasket
■Use caution when opening the oven door during or immediately
after operation. Stand to the side of the oven when opening an
oven door to allow hot air to escape. Keep face well away from the
open door to avoid injury.
■Before self-cleaning an oven, remove the broiler pan, oven racks,
any utensils, as well as excessive spillage
■Do not clean, rub, damage, move, or remove the door gasket, as it
is essential for providing a tight seal during oven operation. If the
gasket becomes worn or excessively soiled with food particles,
replace the gasket.
Prior to Returning Appliance to Service
Prior to returning the appliance to service, make sure that:
■All electrical connections are correct and secure
■All safety grounds (internal and external) are correctly and
securely connected
■All gas connections are secure and have been leak tested using a
gas leak detector or bubble test.
■All panels and components are properly and securely
reassembled
Backguard Ventilation
■To ensure sufficient airflow for proper oven performance, do not
block or obstruct the vents located on the backguard (high
backguard, lowback, or island trim).
■Backguard vents and surrounding areas are hot. Do not place
plastic, other heat-sensitive items, or flammable / combustible
materials on or near the backguard vents, as these areas could
melt or ignite.
■Don’t touch or clean the backguard vent area while the appliance
is on, nor for several minutes after the appliance is turned off, to
prevent burning yourself.

Service Manual for the Thermador Pro Grand Next Generation 48-Inch Natural Gas and LP Gas Ranges, Models: PRG486JDG/01, PRL486JDG/01
58300000159722_ARA_EN_DPage 10 of 92
mCaution
Code Compliance
Local codes vary. Installation, electrical connections, gas connections,
and grounding must comply with all applicable codes.
2 OPERATION AND CONTROLS
2.1 Knobs and Controls
The control knobs each have an icon to identify the burner location.
2.1.1 Standard Burner Knob
1. Press a control knob in, and turn counter-clockwise to HI setting.
The igniter for the burner clicks while sparking until flame ignition.
Burner should ignite within 4 seconds.
2. For the standard burners, rotate the knob to any setting between
the three markers for HI, MED, and SIM.
2.1.2 ExtraLow (XLO) and ExtraHi (XHI) Burner Knobs
XLO and XHI knobs can be set anywhere between the XLO and XHI
markings for a variable range of heat; from 105° F (for XLO) to 185° F
(for XHI).
The burners that have XLO functionality are:
•Left, front
•Left, rear
•Right, front
•Right, rear
The burner at the right, front has XHI functionality (in addition to XLO).
When in XLO mode - the very lowest flame setting, the flame cycles
on for approximately 8 seconds and then turns off for 52 seconds of
each minute.
■Press a control knob in, and turn counter-clockwise to HI or XHI.
The igniter for the burner clicks while sparking until flame ignition.
Burner should ignite within 4 seconds.
2.1.3 Griddle / Grill Control Knob
The griddle / grill knob controls the temperature to the griddle or grill,
from 150° F to 500° F.
■Press and turn the knob clockwise to select a setting.
NOTE: The electric griddle preheat time (the time from when the
griddle is turned on until the preheat light goes off) will vary according
to ambient (room) temperature and the level of electrical service. To
preheat the griddle to 350° F may take approximately 10 to 14
minutes.
2.1.4 Temperature / Function Selector Knob for Large Oven
The Temperature/Function Selector Knob for the large oven enables
selecting a temperature from 150° F to 500° F, as well as one of the
oven function modes.
NOTE: Warm setting displays “Warm’” which is about 150° to 175° F.
■Rotate the outer dial to select a cooking mode, and then rotate the
inner knob to select the temperature.
TESTED IN ACCORDANCE WITH ANSI
Z21.1, THE STANDARD FOR HOUSEHOLD
COOKING GAS APPLIANCES. IN CANADA
TESTED IN ACCORDANCE WITH
CAN/CGA1.1 – M81, THE STANDARD FOR
DOMESTIC GAS RANGES.
Check your local building codes for the proper
method of installation. In the absence of local
codes, this unit should be installed in accordance
with the National Fuel Gas Code No. Z223.1/
NFPA 54 current issue and the National
Electrical Code ANSI/NFPA No. 70 current issue
or the Can – B149 Installation Codes for Gas
Burning Appliances and C22.1 Canadian
Electrical Code Part 1.
It is the responsibility of the owner and the
installer to determine if additional requirements
apply in specific installations.

Service Manual for the Thermador Pro Grand Next Generation 48-Inch Natural Gas and LP Gas Ranges, Models: PRG486JDG/01, PRL486JDG/01
58300000159722_ARA_EN_DPage 11 of 92
2.1.5 Temperature / Function Selector Knob for Small Oven
The Temperature/Function Selector Knob for the small oven enables
selecting a temperature from 150° F to 500° F, as well as one of the
oven function modes.
NOTE: Warm setting displays “Warm’” which is about 150° to 175° F.
■Rotate the outer dial to select a cooking mode, and then rotate the
inner knob to select the temperature.
2.1.6 Oven Light and Panel Light Switches
There is a toggle switch for each oven light, and for the panel light.
2.2 LED Indicators
When a burner is lit, its blue LED indicator is illuminated.
2.3 Automatic Re-Ignition
Each rangetop burner has its own electronic igniter that sparks when
the burner is turned on. If one or more burner blows out, the
respective igniter/electrode automatically re-ignites the flame.
2.4 Operation during a Power Outage
In Case of Power Outage
■When there is a removal of electrical power, the XLO / XHI
burners and griddle/grill cannot be used. Do not attempt to light
them manually during a power outage.
■If for any reason a control knob is on when there is any failure or
removal of electrical power from the appliance (such as a power
outage), immediately turn all control knob(s) to the OFF position.
■Ventilate well by opening a door or window, and wait at least 5
minutes for all the gas to dissipate.
■If you smell gas, refer to the applicable safety precautions stated
in this manual, including the Important Safety Information section
on page 7.
2.5 Rangetop Burner Assembly and Maintop
Components
Figure 3: Rangetop Burner Assembly and Maintop Components
1
Electrode (Igniter)
2
Burner cap
3
Burner base
4
Venturi tube
5
Burner pedestal
6
Jet holder assembly
7
Wire guard clip
8
Burner support rail
9
Heat shield
10
Maintop

Service Manual for the Thermador Pro Grand Next Generation 48-Inch Natural Gas and LP Gas Ranges, Models: PRG486JDG/01, PRL486JDG/01
58300000159722_ARA_EN_DPage 12 of 92
3 TESTING, ADJUSTING, AND TROUBLESHOOTING
RANGETOP BURNERS AND IGNITION
Servicing Burners and Ignition
Burner and ignition servicing must be performed by a qualified
technician. Improper adjustments may be dangerous, cause damage
or harmful by-products, and may void the appliance warranty.
Ignition Hazard
Do not touch burners when the igniters are active (sparking).
3.1 Before Testing
Before testing rangetop burners and ignition, do the following:
1. Reinstall any loose components that may have been removed
earlier, such as burner caps, griddle/grill, and grates. Be
certain that burner caps seat properly into the burner bases,
burner bases and Venturi tubes are aligned correctly, and that
the ignition wires are properly positioned.
2. To test for gas leaks, make sure the electrical power is
removed and the manual gas shut-off valve is open, and then
carefully check range components and gas supply for leaks
using a gas leak detector or bubble test.
3. After gas checks are complete and before testing, connect the
range to the electrical power supply.
3.2 Rangetop Burner Characteristics
If one or more rangetop burner blows out, the respective igniter
electrode automatically re-ignites the flame.
The flame should burn through each burner port, completely around
the burner cap (see Figure 4).
Figure 4: Burner Ports
1
Burner ports
It is normal to hear the following during burner operation:
•A slight sound that is associated with gas combustion and ignition.
There should not be a loud noise.
•A clicking noise every time the gas cycles, coming from the
solenoid valves of the two left burners
•If using LP gas, a slight “pop” sound may be heard at the burner
ports a few seconds after the burner has been turned off.

Service Manual for the Thermador Pro Grand Next Generation 48-Inch Natural Gas and LP Gas Ranges, Models: PRG486JDG/01, PRL486JDG/01
58300000159722_ARA_EN_DPage 13 of 92
3.3 Rangetop Flame Characteristics
Natural gas: The rangetop burner flame color should be blue with no
yellow on the tips (see Figure 5). It is not uncommon to see orange in
the flame color; this indicates the burning of airborne impurities in the
gas, and will disappear with use. See Figure 6 for additional flame
characteristics.
LP gas: Slight yellow tips on the primary flame cone are normal and
may appear after a few minutes. The flame should be stable with no
excessive noise or fluttering. Orange colored streaks in the flame are
produced from burning airborne debris, which is normal at startup,
and should dissipate in a few minutes (see Figure 6).
When the flame is properly adjusted, it should burn completely around
the burner cap, at each burner port (see Figure 4, page 12).
Figure 5: Correct Flame Color and Characteristics
1
Dark blue
2
Secondary cone
3
Light blue
4
Primary cone
Figure 6: Additional Flame Characteristics
NOTE: If rangetop burner/flame characteristics are not adequate, see
Troubleshooting Burners, Flame, and Ignition,page 16).

Service Manual for the Thermador Pro Grand Next Generation 48-Inch Natural Gas and LP Gas Ranges, Models: PRG486JDG/01, PRL486JDG/01
58300000159722_ARA_EN_DPage 14 of 92
3.4 Testing Ignition for Burners
Ignition Hazard
Do not touch the rangetop burners when the igniters are sparking.
3.4.1 Time to Ignite
For each burner, push the control knob in and then turn counter-
clockwise to the highest setting. The igniter should produce a clicking
sound as the burner is sparking, and the burner should light within 4
seconds.
NOTE: It is normal for a burner to spark when a knob is pressed in, or
turned slightly.
3.4.2 Testing Ignition for Standard Burner Settings (HI,
MEDIUM, SIM)
Set the burner knob to HI, and observe flame characteristics
(see Figure 5 and Figure 6). If any burner flame burns primarily
yellow, verify if the burner cap is positioned properly on the burner
base, and then re-test. Repeat test for MEDIUM and SIM settings.
If flame characteristics do not improve, call Thermador technical
support at [phone].
3.4.3 Testing Ignition for XLO Burner Settings
Set the burner knob to XLO and observe if the flame cycles correctly.
It should be on for approximately 8 seconds, and then off for
approximately 52 seconds of each minute.
3.4.4 Testing Broil Burner Ignition
Set the mode to BROIL. After less than a minute (depending on the
model) the burner should ignite. The broil burners do not have an air
shutter, and no adjustment is necessary.
3.4.5 Testing Bake Burner Ignition
Set the oven to BAKE at 350° F. After less than a minute (depending
on the model) the burner should ignite and stay lit until 350° F is
reached. During preheat and also during bake mode, the burner
cycles on and off to maintain the temperature.
3.5 Adjusting Bake Burner Flame with the Air Shutter
The bake burner has an air shutter system (see Figure 7) that is
factory pre-set to burn optimally, but depending on the quality of the
gas available, may require adjustment.
Figure 7: Typical Air Shutter
1
Air shutter
2
Adjustment screw(s)
3
Opening

Service Manual for the Thermador Pro Grand Next Generation 48-Inch Natural Gas and LP Gas Ranges, Models: PRG486JDG/01, PRL486JDG/01
58300000159722_ARA_EN_DPage 15 of 92
1. First remove the bake burner from the burner box. For the large
oven, see Bake Burner Components (Large Oven) – Removal and
Replacement,page 78.For the small oven, see Bake Burner
Components (Small Oven) – Removal and Replacement,page 84.
2. Loosen the adjustment screw, and then rotate the air shutter to
modify the opening as follows:
•If the flame is lifting or blowing, or is not carrying over, rotate
the shutter clockwise to set the opening to a more closed
position.
•If the flame is too yellow, rotate the shutter counter-clockwise
to set the opening to a more open position.
3. Tighten the adjustment screw.
4. Reinstall the burner.
5. Test to evaluate the flame characteristics.
6. Repeat this procedure as needed until the flame characteristics
are optimal.
3.6 Adjusting Rangetop Burner Valves Manually
Although pre-adjusted, if you need to set the valves for the lowest
possible flame setting, then manually adjust the bypass screws on the
valves.
Figure 8: Bypass Screw on Valve (View with Control Panel Removed)
1
Bypass screw on all valves
3.6.1 Special Tools Needed
To reposition the bypass screws for minimum flow settings on manual
valves, use a precision high-strength blade screwdriver, with a 1/8
inch (3.0 mm) wide, .020-inch (0.50 mm) thickness tip.

Service Manual for the Thermador Pro Grand Next Generation 48-Inch Natural Gas and LP Gas Ranges, Models: PRG486JDG/01, PRL486JDG/01
58300000159722_ARA_EN_DPage 16 of 92
3.6.2 Adjusting the Bypass Screws
mCaution
Potentiometer Failure
Failure to turn off electrical power when adjusting bypass screws may
cause failure of the potentiometers
1. Turn off electrical power by unplugging the power cord, or putting
the circuit breaker in the OFF position.
2. Remove knobs from valve stems by slowly pulling knobs straight
out, away from control panel.
3. Remove and retain the right bezel mounting screw.
4. To engage the valve screw, insert the precision screwdriver with a
1/8 inch blade into the same hole in the bezel that was created by
the removal of the right side mounting screw.
5. Turn the valve screw clockwise just until "bottom out" position is
reached. Don’t over-tighten the valve screw.
NOTE: The XLO valves must be in the XLO position for proper
access to the valve screws through clearance hole in the
potentiometer.
NOTE: The griddle/grill is electric, controlled by a thermostat and
does not have a valve that requires adjustment.
Gas Leaks
With electrical power off, carefully check for gas leaks at each gas
component that was removed, replaced, or otherwise serviced using a
gas leak detector (electronic leak detectors are highly recommended)
or bubble test. For non- standard (XLO) valves, the electrical power
may need to be on when testing. Use extreme caution when
performing gas leak testing on XLO valves.
3.7 Troubleshooting Burners, Flame, and Ignition
3.7.1 Burner and Flame Diagnostics for Rangetop Burners
If a rangetop burner clicks (sparks) constantly or if burner doesn’t light
correctly and/or has inadequate burner/flame characteristics (per
Rangetop Burner Characteristics, page 12 and Rangetop Flame
Characteristics, page 13), then do the following:
üCheck if manual shut-off valve is open and unit is receiving gas.
üCheck if the burner cap is properly aligned on the burner base.
üCheck if the burner port is open and not clogged or blocked.
üCheck if the igniter electrode is free from debris and is sparking.
üIf it is suspect that air is in the gas supply lines and system, you
can purge the remaining air by operating one of the burners for
several minutes.
üCheck if a fuse has blown or a circuit breaker has tripped.
üCheck polarity
üFor constant sparking, check wiring connections at ignition (spark)
module and electrode, and also check grounding.
üFor intermittent sparking, check the pot spacing, flame height, and
drafts in kitchen.
üRefer to the Ignition Diagnostics for Rangetop Burners,page 16.
üCall Thermador technical support at [phone] for assistance
if any burners fail to light, or any burners continue to burn yellow.
3.7.2 Ignition Diagnostics for Rangetop Burners
The following flowchart applies in the event a burner fails to ignite.
Before performing steps in the Diagnostic Flowchart for Rangetop
Burner Ignition (Figure 9, page 17), remove electrical power from
appliance during disassembly and during removal and installation
procedures. Restore electrical power when testing the unit if it is
reassembled.

Service Manual for the Thermador Pro Grand Next Generation 48-Inch Natural Gas and LP Gas Ranges, Models: PRG486JDG/01, PRL486JDG/01
58300000159722_ARA_EN_DPage 17 of 92
Figure 9: Diagnostic Flowchart for Rangetop Burner Ignition

Service Manual for the Thermador Pro Grand Next Generation 48-Inch Natural Gas and LP Gas Ranges, Models: PRG486JDG/01, PRL486JDG/01
58300000159722_ARA_EN_DPage 18 of 92
4 DIAGNOSING HOT SURFACE IGNITERS, GRIDDLE /
GRILL ELEMENT, OVEN LIGHTS, TEMP SENSORS
4.1 HSI and Element Diagnostics
4.1.1 Cycle/Circuit Specification
Cavity
Mode
HSI/Element
Watts
Volts
Amps
Ohms
small,
large
Bake
Bake burner HSI
420
120
3.5
34
small,
large
Broil
Broil burner HSI
420
120
3.5
34
small,
large
Convection Bake
Bake burner HSI
420
120
3.5
34
N/A
Griddle / Grill
NOTE: For
specific models
Griddle / grill
element
1600
120
13.3
9.0
4.1.2 Safety Practices for HSI and Element Diagnostics
Observe all pertinent safety practices such as warnings, cautions and
instructions contained in the Safety Precautions to Know Prior to
Servicing section of this manual (page 7), throughout this manual, and
the Installation Manual. Ensure compliance with all applicable codes.
4.1.3 HSI and Element Diagnostic Tips
General
üThe electrical wiring diagram is located behind the kick panel of
the range (see Wiring Diagram, page 6).
üBake and broil modes cannot be operated simultaneously in any
single oven cavity.
Resistance Reading
üYou can perform a resistance reading on an HSI or the griddle/grill
element with the electrical power to the range turned off.
Amperage Reading:
üBroil mode: Broil burner remains on until reaching the maximum
temperature, and cycles off and on to maintain that temperature.
üBake mode: The power to the bake burner cycles on and off at
pre-set intervals when the bake burner is preheating (preheating
indicator light is on) and also during regular bake cycle (after
preheating).
üElectric griddle/grill element and HSIs:
•Check either HSI/element wire with an amp meter and amp
clamp.
NOTE: Always check an HSI at one of its wire connectors
NOTE: Although the HSI may be glowing, if not enough
current is running through it, the safety valve may not open.
, as
the gas burner (attached to the other end of HSI) will ignite.
•Alternatively, you can check the electric griddle/grill element or
HSIs at the wires going to the hot or neutral terminals of the
terminal block.
•Alternatively, you can check the electric griddle/grill element or
HSIs from the corresponding I/O relay terminals on the main
control board.
Temperature Reading
Do not remove the thermocouple prematurely when the oven is hot.
üUse a thermometer with a thermocouple leads to test the oven
temperature. If you leave the thermocouple in the oven during a
speed clean cycle, keep in mind it will take a few hours before the
oven is cool enough if you plan to retrieve the thermocouple.
Convection Bake
üFor convection bake, you can visually inspect if the convection fan
is working. The convection fan only works after the preheating
finishes, thus it may take less time to test the convection fan on
the lowest bake convection setting.
4.2 Oven Light Diagnostics
To diagnose problems with the oven light (for all ovens), see Oven
Light Diagnostics (Figure 10, page 19). Also see Oven Lamp
Transformer Removal and Replacement, page 47).

Service Manual for the Thermador Pro Grand Next Generation 48-Inch Natural Gas and LP Gas Ranges, Models: PRG486JDG/01, PRL486JDG/01
58300000159722_ARA_EN_DPage 19 of 92
Figure 10: Oven Light Diagnostics
Turn light switch OFF and
then open oven door.Is oven light
illuminated?No
Go to Oven Light
Diagnostics 2Go to Oven Light
Diagnostics 2
Yes
Close oven door and
turn light switch ON Is oven light illuminated?
No
Make sure plunger doesn’t get stuck
in closed position. Check wiring and
connections. Replace plunger switch
if necessary.
Continuity across
bulb?
Replace
bulb
No
Is there
12V DC across
socket?
Turn light
switch ON
Make sure
contacts are clean.
Replace bulb if
necessary.
Yes
Remove
light wires
at control
board
Is there
120V AC across
CB outlet?
OVEN LIGHT DIAGNOSTICS 1
OVEN LIGHT DIAGNOSTICS 2
Check transformer (120V AC
input, and 12V DC output).
Check wire continuity. Check
if wires making connections.
Yes
Replace light
wires at
control board
No Is there
120V AC across
light switch?
Yes No
Replace
light switch
No
Trace wire for
short. Replace
control board if
necessary.
Yes
Yes
NOTE: All tests in Oven Light Diagnostics 2 must be performed with the oven door closed, or with the plunger switch pressed in.
TOOLS NEEDED: Multimeter
Turn light switch
OFF and then remove
light bulb.

Service Manual for the Thermador Pro Grand Next Generation 48-Inch Natural Gas and LP Gas Ranges, Models: PRG486JDG/01, PRL486JDG/01
58300000159722_ARA_EN_DPage 20 of 92
4.3 Oven Temperature Sensor Diagnostics
With electrical power OFF, you can perform a resistance reading (and
simultaneous temperature reading) to check the oven temperature
sensor. The resistance fluctuates according to ambient (room)
temperature.
To avoid injury, it is recommended to wait until the appliance at or
near room temperature before performing resistance and temperature
readings.
4.3.1 Resistance and Temperature Values for the Oven
Temperature Sensor
Degrees F Ohms
30 995
40 1016
50 1038
60 1059
70 1080
80 1101
90 1122
100 1143
110 1163
120 1184

Service Manual for the Thermador Pro Grand Next Generation 48-Inch Natural Gas and LP Gas Ranges, Models: PRG486JDG/01, PRL486JDG/01
58300000159722_ARA_EN_DPage 21 of 92
5 FAULT MESSAGES