Service Manual for the Thermador Pro Harmony Range, Model PRL364GDH/01
58300000154022_ARA_EN_D
Page 15 of 68
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)
120V
5V
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