Thermador Pro Harmony PRL364GDH/01 User manual

SERVICE MANUAL
Thermador
Pro Harmony®
Range
Model: PRL364GDH/01

Service Manual for the Thermador Pro Harmony Range, Model PRL364GDH/01
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TABLE OF CONTENTS
1General.......................................................................................4
1.1 Technical Documents to Read Prior to Servicing ........................... 4
1.2 Wiring Diagram................................................................................ 4
1.3 Data Rating Plate............................................................................ 4
1.4 Recommended Tools and Supplies................................................ 5
1.5 Important Safety Information........................................................... 5
1.5.1 Safety Symbols Used In This Manual..................................... 5
1.5.2 Safety Precautions to Know Prior to Servicing ....................... 5
2Operation ...................................................................................8
2.1 Control Knobs.................................................................................. 8
2.1.1 ExtraLow Feature.................................................................... 8
2.1.2 Griddle Control Knob............................................................... 8
2.1.3 Temperature Selector Knob.................................................... 9
2.1.4 5-Position Oven Function Selector Knob................................ 9
2.2 Automatic Re-Ignition...................................................................... 9
2.3 Operation during a Power Outage .................................................. 9
2.3.1 Cooling Fan –Automatic Operation.......................................... 9
2.4 Burner Assembly and Maintop Components ................................ 10
3Testing, Setting, Troubleshooting - Burners and Ignition....10
3.1 Before Testing...............................................................................10
3.1.1 Oven Temperature Testing.....................................................10
3.2 Burner Characteristics................................................................... 11
3.2.1 Flame Characteristics............................................................ 11
3.3 Testing Burner Ignition..................................................................12
3.3.1 Testing Cooktop Burner Ignition............................................12
3.3.1.1 Testing the HI Setting........................................................12
3.3.1.2 Testing the SIM Setting.....................................................12
3.3.1.3 Testing the XLO Setting.................................................... 12
3.3.2 Testing Bake Burner Ignition.................................................12
3.3.3 Testing Broil Burner Ignition..................................................12
3.4 Manually Setting Burner Valves....................................................12
3.4.1 Tools Needed........................................................................ 12
3.4.2 Adjusting the Bypass Screws................................................ 12
3.5 Burner, Flame, and Ignition Troubleshooting................................13
3.5.1 Cooktop Burners –Burner and Flame Diagnostics...............13
3.5.1.1 Uneven Flame Distribution & Flame Noise Diagnostics ...13
3.5.2 Ignition Diagnostics ............................................................... 14
4Oven Light Diagnostics ..........................................................16
5Fault Codes..............................................................................17
6Service and Repair..................................................................19
6.1 Preparing the Range for Servicing................................................19
6.2 Accessing Components under the Maintop .................................. 19
6.2.1 Removing Knobs, Grates, Griddle, and Burner Assemblies. 19
6.2.2 Removing the Maintops.........................................................21
6.2.3 Removing the Heat Shield.....................................................22
6.2.4 Griddle Removal and Replacement ......................................22
6.2.5 Burner Support Rail Removal and Replacement..................25
6.3 Removal and Replacement of Top-Accessible Components........27
6.3.1 Jet Holder Assembly Removal and Replacement.................27
6.3.2 Manifold Removal and Replacement.................................... 28

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6.3.3 Standard Valve Removal and Replacement.........................30
6.3.4 Microswitch Removal and Replacement............................... 31
6.3.5 Solenoid Valve Removal and Replacement..........................32
6.3.6 XLO Valve Removal and Replacement................................. 33
6.3.7 Potentiometer Removal and Replacement ...........................35
6.3.8 Temperature Selector Removal and Replacement............... 36
6.3.9 5-Position Oven Function Selector –Removal and
Replacement.........................................................................................37
6.3.10 Dual Valve Removal and Replacement ................................38
6.3.11 Regulator Removal and Replacement.................................. 39
6.3.12 Ignition Device Removal and Replacement..........................40
6.3.13 LED Indicator Removal and Replacement............................40
6.3.14 Control Board Removal and Replacement ...........................41
6.3.15 Simmer Control Board Removal and Replacement..............42
6.4 Removal and Replacement of Back-Accessible Components......43
6.4.1 Backguard and Island Trim Removal and Replacement....... 43
6.4.2 Back Panel Removal and Replacement................................44
6.4.3 Terminal Block Removal and Replacement.......................... 45
6.4.4 Electrical Wiring Connections at the Terminal Block ............45
6.4.5 Cooling Fan Removal and Replacement ..............................45
6.4.6 Broil Burner Assembly Removal and Replacement.............. 47
6.4.7 Convection Components –Removal and Replacement....... 49
6.5 Removal and Replacement of Front-Accessible Components ..... 52
6.5.1 Control Panel Removal and Replacement............................52
6.5.2 Bake Burner Components –Removal and Replacement..... 54
6.5.3 Oven Temperature Sensor Removal and Replacement.......58
6.5.4 Oven Lamp Removal and Replacement............................... 59
6.5.5 Door Removal and Installation..............................................60
6.5.5.1 Removing the Door ...........................................................60
6.5.5.2 Installing the Door .............................................................60
6.5.6 Door Handle Components - Removal and Replacement......60
6.5.6.1 Removing Door Handle Components ...............................61
6.5.6.2 Installing Door Handle Components .................................61
6.5.7 Door Gasket Removal and Replacement..............................61
6.5.8 Kick Panel Removal and Replacement.................................62
6.5.9 Bottom Plate of Front Frame –Removal and Replacement.63
6.5.10 Door Hinge Receiver Removal and Replacement ................64
6.5.11 Door Hinge Removal and Replacement................................65
6.5.12 Thermostat Removal and Replacement................................66
7Before Returning Appliance to Service .................................67
8Clean-Up ..................................................................................67
9Additional Resources..............................................................68
9.1 QuickFinder...................................................................................68
9.2 Technical Support ......................................................................... 68

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1 GENERAL
This manual contains information that is necessary for servicing the
following Thermador Pro Harmony Range:
PRL364GDH/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 Technical Support at [phone]
1.1 Technical Documents to Read Prior to Servicing
Before you start servicing, check QuickFinder for all other technical
documents associated with this specific appliance.
1.2 Wiring Diagram
The Wiring / schematic diagram is located behind the kick panel
(see Figure 1).
1.3 Data Rating Plate
The data rating plate which shows the model, serial, and FD number
is located underneath the control panel, as shown in Figure 1. This
information 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 and Wiring Diagram Locations

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1.4 Recommended Tools and Supplies
The following tools and supplies are recommended to use when
servicing this appliance:
Caution
Power Drivers
■If using a power driver, set the clutch to the lowest setting
Driver sizes: T-10, T-20, T-25, T-30
1/4 inch nut driver or 1/4 inch socket wrench / ratchet
Wrench sizes: 1/2 inch, 1/4 inch, 5/16 inch, 11/32 inch open-end
Socket wrench / ratchet 11/32 inch
Swivel head driver with an 11/32 inch, deep-well socket
Large nut driver (1 inch min.) with a deep-well socket
Long, hand-held T-20 driver
Adjustable wrench
Pipe wrench
Precision screwdriver with a high-strength blade, 1/8-inch
(3.0 mm) wide, .020-inch (0.50 mm) thickness tip
Flat blade screwdrivers: large, small
Slip joint pliers
Needle-Nose pliers
Hook or non-straight hex key (Allen wrench)
Protective gloves
Gas leak test equipment
Pipe sealant
Small mirror
Protective eye wear (such as glasses or goggles)
Flashlight
Amp meter
Thermometer with thermocouple leads
Multimeter
Air lifter / air dolly
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
This symbol alerts you to dangers that may result in bodily injury or
death.
Caution
This symbol alerts 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 by removing the fuse.
■Turn off the gas supply to the appliance.
■Make sure grates and burner assemblies are cool before
removing them.

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Replacement Parts
Use only authorized replacement parts per catalog 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 Hazard
■The griddle plate must always be correctly in place when the
griddle is turned on.
What to Do If You Smell Gas
■Do not try to light any appliance
■Do not touch any electrical switch
■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.
■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 or bubble test.
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 cooktop burners, infrared broil burner, bake
burner, heat deflector, and interior oven surfaces.

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In Case of Power Outage
1. 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.
2. Ventilate by opening a door or window, and wait at least 5minutes
for all the gas to dissipate.
3. If you smell gas, refer to the applicable safety precautions stated
in this manual.
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.
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.
Fiberglass Insulation
Wear gloves when handling fiberglass insulation.
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
Caution
Code Compliance
Local codes vary. Installation, electrical connections, gas connections,
and grounding must comply with all applicable codes.
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.

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2 OPERATION
2.1 Control Knobs
The control knobs for each of the burners are located on the control
panel, with an icon to identify the location on the range (see Figure 2).
The left-most front and left-most rear burners have the ExtraLow
(XLO) feature.
Figure 2: Burner Control Knobs
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 non-XLO burners, rotate the knob to any setting between
HI and SIM. For the XLO (left front and left rear) burners, rotate
the knob to any setting between HI and XLO.
NOTE: The blue LED indicator lights up when burners are lit.
2.1.1 ExtraLow Feature
When the knob is set to XLO - the very lowest setting, the flame
cycles on for approximately 8 seconds and then turns off for 52
seconds of each minute.
The knob can also be set between SIM and XLO for a variable range
of low heat, with the flame cycling on and off at a different frequency
than the XLO setting (see Figure 3).
Figure 3: XLO Settings
2.1.2 Griddle Control Knob
The griddle knob controls the temperature to the griddle, from 150° F
to 500° F (see Figure 4).
There are no fixed settings on the knob. Press and turn the knob
clockwise to select a setting.
Figure 4: Griddle Control Knob

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2.1.3 Temperature Selector Knob
For each oven, use the respective Temperature Selector knob
(see Figure 5).
Figure 5: Temperature Selector Knob
2.1.4 5-Position Oven Function Selector Knob
Use this knob for oven bake, extended bake (Sabbath mode),
convection bake, and broil (see Figure 6).
Figure 6: 5-Position Oven Function Selector Knob
2.2 Automatic Re-Ignition
Each 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.
2.3 Operation during a Power Outage
When there is a removal of electrical power, the XLO burners cannot
be used. Do not attempt to light them manually.
Caution
Power Outage Precautions
■Ventilate well by opening a door or window, and wait at least five
minutes until all the gas dissipates.
■If you smell gas, comply with the warnings and precautions in the
Important Safety Information section (page 5) of this manual.
2.3.1 Cooling Fan –Automatic Operation
Cooling Fan - Automatic Operation
■Pro Range equipped with original control part # 00649291
The cooling fan energizes when the oven cavity reaches 425 Deg F.
During cool down the fan de-energizes when the cavity cools to 375 Deg F.
■Pro Range equipped with replacement control part # 00709785
The cooling fan energizes when the oven cavity reaches 300 Deg F.
During cool down the fan de-energizes when the cavity cools to 250 Deg F.
Part # 00709785 is standard on most Pro Ranges FD # 9112 and later

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2.4 Burner Assembly and Maintop Components
Figure 7: Burner Assembly and Maintop Components
3 TESTING, SETTING, TROUBLESHOOTING -
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 the burners and ignition, do the following:
1. Reinstall any loose components that may have been removed
earlier, such as burner caps, griddle, and grates. Be certain that
burner caps seat properly into the burner bases, burner pedestal
and Venturi tube 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.
3.1.1 Oven Temperature Testing
**Do not remove the thermocouple prematurely when the oven is hot.
Test oven temperature using a thermometer with a thermocouple
lead. 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 to retrieve the thermocouple.
Convection Bake
For 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.

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3.2 Burner Characteristics
If one or more burner blows out, the respective igniter electrode
automatically re-ignites the flame.
At each burner port the flame should burn completely around the
burner cap.
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
For LP gas, a slight “pop” sound may be heard at the burner ports
a few seconds after the burner has been turned off
NOTE: If burner characteristics are not adequate, see Burner, Flame,
and Ignition Troubleshooting, page 13.
3.2.1 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 9).
When the flame is properly adjusted, it should burn at each burner
port, completely around the burner cap (see Figure 8).
NOTE: If flame characteristics are not adequate, see Burner, Flame,
and Ignition Troubleshooting, page 13.
Figure 8: Burner Ports
Figure 9: Additional Flame Characteristics

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3.3 Testing Burner Ignition
3.3.1 Testing Cooktop Burner Ignition
Ignition Hazard
Do not touch the cooktop burners when the igniters are sparking.
For each burner, push the control knob in and then turn counter-
clockwise to HI. The igniter should produce a clicking sound as the
burner is sparking, and the burner should light within four seconds.
3.3.1.1 Testing the HI Setting
Set the burner knob to HI, and observe flame characteristics
(see Figure 9). If any burner flame burns primarily yellow, verify if the
burner cap is positioned properly on the burner base, and then re-test.
If flame characteristics do not improve, call Thermador technical
support at [phone].
3.3.1.2 Testing the SIM Setting
Set the burner knob to SIM. Make sure that the flame completely
surrounds the burner. There should be a flame at each burner port
and there should not be an air gap between the flame and the burner.
If the flame does not extend completely around any of the burners,
call Thermador technical support at [phone].
3.3.1.3 Testing the XLO Setting
The left-front and left-back burners have the XLO feature. Set the
burner knob to XLO and observe if the flame cycles correctly - on for
approximately 8 seconds, and then off for 52 seconds of each minute.
3.3.2 Testing Bake Burner Ignition
Set the oven to BAKE at 350° F. After 30–75 seconds the burner
should ignite and stay lit until 350° F is reached. Then it should shut
off. From this point forward, the burner should cycle on and off to
maintain the temperature.
NOTE: The air shutter for the bake burner is factory pre-set at a fully-
opened position for all conditions, and doesn’t require adjustment.
3.3.3 Testing Broil Burner Ignition
Set the mode to BROIL. After 30–75 seconds the burner should
ignite. The infrared ceramic broiler does not require any adjustment.
3.4 Manually Setting Burner Valves
Although pre-adjusted, if you need to set the XLO valves and
standard valves for the lowest possible flame setting, then manually
adjust the bypass screws on all valves.
3.4.1 Tools Needed
■T-20 driver
■A precision high-strength blade screwdriver, with 1/8 inch (3.0mm)
wide, .020 inch (0.50mm) thickness tip should be used to
reposition the bypass screws for minimum flow settings on manual
valves.
3.4.2 Adjusting the Bypass Screws
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 bezel mounting screw located to the right
of the valve stem, using a T-20 driver (see Figure 10, page 13).
4. To engage the valve screw, insert the precision screwdriver with
1/8-inch blade into the same hole in the bezel that was created by
the removal of the mounting screw (see Figure 11, page 13).
5. Turn the valve screw clockwise just until "bottom out" position is
reached. DO NOT over-tighten the valve screw (see Figure 11).
NOTE: The two valves for XLO operation (farthest left on control
panel) must be in the OFF position for proper access to the valve
screws through clearance holes in the XLO potentiometers.

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Gas Leaks
Carefully check for gas leaks at each gas component that was
removed, replaced, or otherwise serviced using a gas leak detector or
bubble test.
Figure 10: Removing the Bezel Mounting Screw
Figure 11: Accessing and Setting the Bypass Screw
3.5 Burner, Flame, and Ignition Troubleshooting
3.5.1 Cooktop Burners –Burner and Flame Diagnostics
If a burner clicks (sparks) constantly, or if burner doesn’t light correctly
and/or has inadequate burner/flame characteristics (per Burner
Characteristics page 11 and Flame Characteristics page 11), then do
the following:
Check if the manual shut-off valve is open and the unit is receiving
gas (natural gas or liquid propane).
Check if the burner cap is properly aligned on the burner base.
Check if the burner port is open and not clogged or blocked.
Check if the igniter electrode is free from debris and is sparking.
If 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.
Check if a fuse has blown or a circuit breaker has tripped.
For constant sparking, check wiring connections at ignition device
and electrode, and also check grounding
Refer to the Ignition Diagnostics, page 14.
Call Thermador technical support at [phone] for assistance
if any burners fail to light, or any burners continue to burn yellow.
3.5.1.1 Uneven Flame Distribution & Flame Noise Diagnostics
If there is an uneven flame distribution around the burner ports and/or
a loud noise emanating from the flame, it could be caused by bad
combustion due to a misalignment of the gas jet assembly and Venturi
tube. For optimal combustion, the jet needs to be centered inside of
the Venturi tube. A misalignment of these two components can be
caused by either the pedestal burner base and/or jet assembly not
positioned correctly onto the maintop –resulting in a poor mixture of
gas and air. Perform the following diagnostic steps:

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Hot Burner Components
Always use a pot holder to handle a hot burner cap, Venturi tube, or
any other burner assembly component to prevent injury.
Figure 12: Problematic Burner –on High with Gaps and Uneven Flame
(Left Image) and on Low (Right Image)
1. Check if the burner cap is properly installed.
2. If problem persists, switch the burner cap with one from a burner
that is operating correctly. If problem is still not resolved, proceed
to the next steps:
3. Remove the star burner top and then the pedestal burner base per
the Removing Knobs, Grates, Griddle, and Burner Assemblies
procedure, page 19.
4. Make sure the jet assembly is correctly seated so that the raised
part protrudes through the respective contour on the maintop
(see Figure 13) and that the electrode ignition wire moves freely
through the hole in the maintop (see Figure 24, page 20).
5. Reinstall the pedestal burner base (without the Venturi tube). Be
careful not to over torque the screw on the pedestal burner base.
6. Insert the Venturi tube inside the pedestal burner base and make
sure it can slide up and down freely without grinding or catching
(see Figure 14).
7. Reinstall the rest of the burner assembly, and test the flame on
low and high settings.
Figure 13: Incorrect Jet Assembly-to-Maintop Alignment (Left Image)
and Proper Jet Assembly-to-Maintop Position (Right Image)
Figure 14: Pedestal Burner Base –Jet Centered Inside Venturi Tube
3.5.2 Ignition Diagnostics
The following flowchart applies in the event a burner fails to ignite.
Before performing steps in the Cooktop Burner - Ignition Diagnostics
Flowchart (Figure 15, page 15), remove electrical power from
appliance during disassembly and during removal and installation
procedures. Restore electrical power when testing the unit if it is
reassembled.

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Figure 15: Ignition Diagnostics Flowchart
STANDARD BURNERS
No ignition Burner LED
Indicator is on?
120 VAC into
Microswitch checks
out ok?
Replace
Microswitch Yes
Sparking?Yes
120 VAC into
Ignition Device
checks out ok ?
No
Problem persists after
checking all connections
on Simmer Control Board?
Replace
Spark Module
(Ignition
Device)
Gas supply into
Regulator?
110V DC
into Solenoid
Valve?
Contact the
gas supplier Replace Regulator
Yes
Replace
Simmer
Control Board
Replace
Solenoid
Valve
Check burner ports for
blockage, check if burner
cap is aligned on base
Problem persists after
checking electrical power
supply (circuit breaker/
fuse, power cord, wiring
at terminal box)?
No
Replace LED
Indicator
Problem persists after
checking wire connection to
electrode, and checking if
electrode is free of debris?
Yes
No
Yes
Is gas present
at burner?
Yes
No (Standard burners)
No (XLO burners)
N
L1 Standard
Valve
Spark
Module
(Ignition
Device)
120V
Electrode
N
Diode LED
Indicator
Burner
120V
XLO BURNERS
L1 Potentiometer Simmer
Controller
Board
Spark
Module
(Ignition
Device)
120V5V
Solenoid
Valve
110V DC Electrode
120V
Diode LED
Indicator
Burner
N
Yes Check wiring from
Microswitch to Spark
Module (Ignition Device)
No (Standard burners)
5V from
Potentiometer to
Simmer Control
Board?
No
Problem persists
after checking all
connections on
Potentiometer?
Yes
No Yes
Yes
No
Replace
Potentiometer
Yes
5V from
Potentiometer to
Simmer Control
Board?
No (XLO burners) No
Yes
Yes

Service Manual for the Thermador Pro Harmony Range, Model PRL364GDH/01
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4 OVEN LIGHT DIAGNOSTICS
Figure 16: Oven Light Diagnostics
Turn light switch OFF and
then open oven door. Is oven light illuminated? No
Go to Oven Light
Diagnostics 2 Go 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 Harmony Range, Model PRL364GDH/01
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5 FAULT CODES
When a fault is detected, this appliance will display a fault code
(see Figure 20, on page 18). The fault codes are represented by the
manner in which two blue LED indicators are blinking.
Depending on the range model, the blue LEDs that blink are located
either horizontally or vertically on the control panel. The horizontal
positioned blue LEDs (see Figure 17 and Figure 18) will first blink on
the left and then the right, and the vertical positioned blue LEDs (see
Figure 19) will first blink on the top and then the bottom.
For example, if the first LED blinks 4consecutive times followed
immediately by the second LED blinking 3times, that represents a
fault code of 43 on the chart (see Figure 20, on page 18).
Figure 17: Two Horizontal LED Indicators
Figure 18: Three Horizontal LED Indicators (Only Blue LEDs Blink)
Figure 19: Two Vertical LED Indicators

Service Manual for the Thermador Pro Harmony Range, Model PRL364GDH/01
58300000154022_ARA_EN_D Page 18 of 68
Figure 20: Fault Codes

Service Manual for the Thermador Pro Harmony Range, Model PRL364GDH/01
58300000154022_ARA_EN_D Page 19 of 68
6 SERVICE AND REPAIR
6.1 Preparing the Range for Servicing
For most servicing of this appliance (for example, involving
disassembly, removal or installation), you will need to do the following
prior to starting:
■Turn off the gas supply to the range by closing the gas valve at
the wall.
■Turn off the electrical power to the range by removing the power
cord from the electrical outlet, and putting the circuit breaker in the
OFF position or by removing the fuse.
■Make sure the range is not hot.
If testing the appliance requires the use of electrical power and/or an
open gas supply, exercise extreme caution.
6.2 Accessing Components under the Maintop
This section contains the steps required to gain access to the
components located under the maintop.
6.2.1 Removing Knobs, Grates, Griddle, and Burner
Assemblies
To access and service components located underneath the maintop
(see Figure 7), remove the knobs, grates, griddle, burner assemblies,
maintop, and heat shield:
1. [Optional –only if a component attached to a knob needs
replacing] Remove knob from valve stem by slowly pulling knob
straight out, away from control panel.
2. Remove grates.
3. Remove all Star burner caps.
4. Remove and retain the two T-30 screws from each brass Star
burner base (see Figure 21).
Figure 21: Star Burner Base (Generation 5 Design Shown)
Caution
Fragile Component
The electrode is a ceramic component that can be brittle and crack
easily.

Service Manual for the Thermador Pro Harmony Range, Model PRL364GDH/01
58300000154022_ARA_EN_D Page 20 of 68
5. While lifting the brass burner base, carefully depress the locking
tab on the female terminal of the igniter wire, and gently pull to
detach from the electrode (see Figure 22 and Figure 23).
Figure 22: Igniter Wire Attached to Electrode
Figure 23: Igniter Wire Locking Tab
6. If the electrode needs replacing, remove and retain the small T-10
screw to detach it from the brass burner base. If not, leave it
attached to the brass burner base.
7. Remove and retain the T-30 screw holding the cast iron pedestal
burner to the maintop.
8. Remove the pedestal burner with the Venturi tube still attached to
it, while gently pulling the ignition wire through (see Figure 24).
-OR-
Alternatively, you can first lift the Venturi tube out from the
pedestal burner, before removing the pedestal burner from the
maintop.
Figure 24: Pedestal Burner with Venturi Tube
Press tab
to detach
from
electrode