Greenheck IG / IGX (464104 IOM) (Pre-2009) - Manual (Page 66)

66
Troubleshooting
Single Stage or 2:1 Staged Furnace Will Not Light
Internal control failure?
(ignition controller LED on)
Ignition controller (IC1) failed.
(Replace ignition controller)
High limit (HLC#) open?
Discharge temperature was above high limit setting.
Wait for high limit to cool and reset.
24 VAC across A and X?
Discharge air selector (TS2) improperly set or faulty
Adjust setting (see staged start-up) or replace sensor
Furnace stage one contact (SC1-1) defective (stage only)
Replace furnace stage one contact
24 VAC across 20 and X?
Supply starter relay (ST1) defective
Replace supply starter relay
Optional inlet air sensor contact (TS1) open
Adjust inlet air sensor setting (refer to blower start-up)
Yes
No
No
Yes
No
Yes
Yes
24 VAC across W1 and X?
Heat switch (S3) open or not wired
Close or replace heat switch
No
Yes
24 VAC across R and X?
Main disconnect (DS1) open or defective
Close, repair or replace
Fusing (FU6 and/or FU8) blown
Replace blown fusing
Main transformer (TR1) fault
Replace main transformer
No
Yes
Airflow fault?
(ignition controller LED
blinking once)
Combustion blower (CM1) not functioning
Replace fusing (FU9), combusting blower or relay (CM1)
Air proving switch (PS2) defective.
Replace air proving switch
Yes
No
Ignition lockout?
(ignition controller LED
blinking three times)
Improper manifold pressure
Set high and low manifold pressure (refer to start-up)
Faulty spark rod or spark gap does not equal 1 ⁄
8
in.
Replace spark rod or adjust gap to 1 ⁄
8
in.
Yes
No
Troubleshooting
Everything is working
properly, consult factory.
Yes