Proheat X45–School Bus - Manual (Page 71)

PROHEAT INSTALLATION & SERVICE 5-14
Flame Sensor
Check: Flame Sensor
a) Flame sensor operation.
Test Procedure — Flame Sensor Circuit:
a) Check cleanliness of the flame sensor.
b) To test flame sensor for operation:
Spare Flame Sensor Available – Check:
i) Ensure unit is powered off. Disconnect flame sensor.
ii) Connect known good Flame Sensor to harness.
iii) Hold up known good Flame Sensor to Inspection Port.
iv) Start heater with the known good flame sensor held to
Inspection Port.
If heater runs for at least 90 seconds with the known good flame
sensor, replace flame sensor as it is faulty.
Spare Flame Sensor Not Available – Check:
i) Ensure unit is powered off. Disconnect flame sensor.
ii) Shine incandescent flashlight directly at sensor.
iii) Start heater with a flashlight shined directly at the sensor.
iv) Code 6 should be displayed immediately on start up.
If Code 6 does not display immediately on start up, replace flame
sensor as it is faulty.
NOTICE
If the lens is dirty, the sensor does
not properly “see” the flame.
NOTICE
DO NOT use an LED flashlight. Only
an incandescent flashlight will check
the sensor operation.