Element Diagnostics; Safety Practices For Element Diagnostics; Element Diagnostic Tips - Thermador PRL304EG Service Manual

Service Manual for Thermador Pro Grand LP Gas Ranges, Models: PRL304EG, PRL364EDG, PRL364ELG, PRL366EG, PRL484ECG, PRL486EDG, PRL486EDPG, PRL484ELG
3.7.3

Element Diagnostics

Use the following element circuit specification for troubleshooting:
Cavity Mode Element
18-inch Bake Bake burner HSI
30-inch
36-inch
18-inch Broil Broil burner HSI
30-inch
36-inch
30-inch Convection Bake Bake burner HSI
36-inch
Griddle Griddle element
NOTE: For some
N/A
36-inch and
48-inch models
Grill burner HSI
Grill Hot Surface
N/A
Igniter (HSI)
NOTE: For
specific 36-inch
and 48-inch
models.
Figure 20: Element Circuit Specification
3.7.3.1

Safety Practices for 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 6), throughout this manual, and
the Installation Manual. Ensure compliance with all applicable codes.
3.7.3.2

Element Diagnostic Tips

General
 The electrical wiring diagram is located behind the kick panel of
the range (see Wiring Diagram, page 5).
 Bake and broil modes cannot be operated simultaneously in any
single oven cavity.
Resistance Reading
 You can perform a resistance reading on an element with the
electrical power to the range turned off.
58300000156573_ARA_EN_B
Watts Volts Amps Ohms
420 120 3.5 34
420 120 3.5 34
420 120 3.5 34
1600 120 13.3 9.0
120 to 0.4 to 300 to
120
48 1.0 120
Amperage Readings
 Bake mode: The power to the bake element cycles on and off at
pre-set intervals when the bake element is preheating (preheating
indicator light is on) and also during regular bake cycle (after
preheating). After preheating, the broil element is on for 4 seconds
out of every 60 seconds for food browning.
 Broil mode: Broil element remains on until reaching the maximum
temperature, and cycles off and on to maintain that temperature.
 Electric griddle element and hot surface igniters (HSIs):

Check either of element wires with an amp meter and amp clamp.
NOTE: Check the HSIs at one of the wire connectors, as the gas
burner (attached to HSI) will ignite.
NOTE: Although the HSI may be glowing, if not enough current is
running through it, the safety valve may fail.

Alternatively, you can check the griddle element or HSIs at the
wires going to the hot or neutral terminals of the terminal block.

Alternatively, you can check the electric griddle element or HSIs
from the corresponding I/O relay terminals on the main control
board. Depending on the model, you may have to remove the
griddle/grill in order to access the control board.
Temperature Reading
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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