8 G Gas Combustion Combination Controls and Systems—G891 Pulse Ignition Control
Table 3: Spark is Present But Main Burner Will Not Light
Possible Causes
Corrective Actions
24 VAC not present at main valve terminal
on ignition control
Replace ignition control.
Main valve wiring lacking continuity or
good insulation
Replace wiring.
24 VAC present at main valve terminals,
but main valve does not open
Replace gas valve.
Incorrect gas pressure
Adjust gas pressure to appliance
specifications or contact local gas company.
Spark gap not located in gas stream
Re-locate spark igniter.
Table 4: Main Burner Lights But Does Not Stay Lit
Possible Causes
Corrective Actions
Flame sensor cable in contact with spark
cable
Separate cables.
Flame sensor cable lacking continuity or
good insulation
Replace cable.
Flame sensor ceramic cracked
Replace flame sensor.
Flame sensor electrode dirty
Clean with steel wool or replace.
Flame sensor positioned incorrectly
Position flame sensor so that top half is
exposed to the blue portion of flame.
Poor grounds
Make certain a ground screw is inserted
through the ground lug on the ignition control.
Defective ignition control
If flame sensing current is above the
recommended level (0.5 microamperes) and
main burner will not stay lit, then replace
ignition control.
!
CAUTION:
Label all wires prior to disconnection when
servicing controls. Wiring errors can cause
improper and dangerous operation.
Do not attempt field repairs to the ignition control. Use only an exact or
recommended replacement control. For a replacement control or
accessories, contact the original equipment manufacturer or authorized
wholesaler.
Repairs and
Replacement
Controls Group
FAN 121
507 E. Michigan Street
Installation Sheets Manual
P.O. Box 423
Printed in U.S.A.
Milwaukee, WI 53201
