Crown Boiler CWD138 - Manual (Page 66)

64 64
Does
spark stop
when pilot
lights?
24 volts
across
terminals PV
& MV/PV at
module?
Pulsing
Spark
across
ignitor/sensor
gap?
Y
* Module is in soft
lockout. Reset by
momentarily
interupting power to
boiler and waiting for
prepurge.
* Break in spark
cable insulation
* Break in pilot
porcelain
* Incorrect pilot
spark gap
* Loose connection
in spark cable
* Loose ground
connection
* Defective Ignition
Module
N
Pilot
lights?
Y
N
N
* Defective
module
24 volts
across PV &
MV/PV at gas
valve?
* Defective EI
wiring harness.
N
* Loose connection in
ignition cable or
ground wire
* Pilot electrode
porcelain cracked
* Pilot flame not
covering gap
between electrode
and grounding
strap
* Low inlet gas
pressure
* Defective module
Main
burner
lights?
N
Y
24VAC
across
terminals MV
& MV/PV on
module?
Y
N
* Defective
module
24 volts
between MV &
MV/PV on gas
valve?
* Defective
gas valve
*Defective EI
harness
END
START
(24 volts is present across 24V and 24V (GND) on
Ignition Module, 30 second prepurge period has
passed)
N
Y
N
Y
Y
Y
* Low inlet gas pressure
* Plugged, kinked or leaking
pilot tubing
* Plugged pilot orifice
* Gas line not purged of air
* Defective pilot assembly
* Defective gas valve
IMPORTANT: ALL PILOT TROUBLESHOOTING
ON THIS CHART MUST BE PERFORMED AFTER
THE 30 SECOND PREPURGE HAS ENDED AND
BEFORE THE END OF THE 90 SECOND TRIAL
FOR IGNITION PERIOD.
TROUBLESHOOTING CHART FOR IGNITION SYSTEMS USING UT 1003-626A IGNITION MODULE