Greenheck PVF/PVG Indirect Gas-Fired Heat Modules (474645) - Manual (Page 23)

Indirect Gas-Fired Heat Modules 23
®
4:1 Modulating Furnace Will Not Light
In all cases, verify correct terminals as shown on the unit-specific wiring diagram.
Troubleshooting
Ignition controller (IC#)
red LED blinks
7 times or is on
Ignition controller(s) (IC#) failed
Replace faulty ignition controller(s)
High limit switch (HLC#) open?
Discharge temperature was above high limit setting
Let cool then reset high limit.
Yes
Yes
No
Ignition controller (IC#)
red LED
blinks 6 times
Pressure switch (PS2) failure
Repair or replace pressure switch (PS2)
Combustion blower (CM) not functioning
Replace fusing (FU7), combustion blower or relay (CM)
Yes
No
Ignition controller (IC#)
red LED blinks
1 time, 2 times or 4 times
Improper manifold pressure
Set high and low manifold pressure
(refer to 4:1 Electronic Modulation Start-Up section)
Faulty spark rod or spark gap does not equal 1/8 inch
Replace spark rod or adjust gap to 1/8 inch
Yes
No
...continued from previous page
Secondary transformer (TR6) defective
Replace secondary transformer (TR6)
Furnace controller (SC1) defective
Replace furnace controller (SC1)
No
24 VAC between 24 VAC terminals
on mod valve
No
Yes
No
Yes
10 VDC between terminals
(+) and (-) on mod valve
Everything is working properly,
consult factory.