66369-YIM-D-1004
58
Unitary Products Group
Furnace lights with roll-out or one burner has delayed
ignition.
1.
Make sure that the pilot burner is aligned properly
with the carryover as described in “PILOT CHECK-
OUT” Page 50.
2.
Make sure that the carryovers on adjoining burners
are screwed fast and are level with respect to one
another.
Main burners light but exhibit erratic flame characteris-
tics.
1.
Adjust air shutters as described in “BURNER AIR
SHUTTER ADJUSTMENT” Page 50.
2.
Check the main burner orifices for obstruction and
alignment. Removal procedure is described in
BURNER INSTRUCTIONS Page 50. Clean or
replace burner orifices and burners as needed.
UNIT FLASH CODES
Various flash codes are utilized by the unit control
board (UCB) to aid in troubleshooting. Flash codes are
distinguished by the short on and off cycle used
(approximately 200ms on and 200ms off). To show
normal operation, the control board flashes a 1 second
on, 1 second off "heartbeat" during normal operation.
This is to verify that the UCB is functioning correctly.
Do not confuse this with an error flash code. To prevent
confusion, a 1-flash, flash code is not used.
Current alarms are flashed on the UCB LED. Pressing
and releasing the ALARMS button on the UCB can
check the alarm history. The UCB will cycle through the
last five (5) alarms, most recent to oldest, separating
each alarm flash code by approximately 2 seconds.
In some cases, it may be necessary to "zero" the
ASCD for the compressors in order to perform trouble-
shooting. To reset all ASCDs for one cycle, press and
release the UCB TEST button once.
TABLE 26: UNIT CONTROL BOARD FLASH CODES
Flash Code
Description
On Steady
Control Failure - Replace Control
Heart Beat
Normal Operation
1 Flash
Not Applicable
2 Flashes
Control waiting ASCD
1
1.
These flash codes do not represent alarms.
3 Flashes
HPS1 - Compressor Lock out
4 Flashes
HPS2 - Compressor Lock out
5 Flashes
LPS1 - Compressor Lock out
6 Flashes
LPS2 - Compressor Lock out
7 Flashes
FS1 - Compressor Lock out
8 Flashes
FS2 - Compressor Lock out
9 Flashes
Ignition Control Locked Out/
Ignition Control Failure / Limit Switch Trip / No
Jumper Plug in Heat Section
10 Flashes
Compressors Locked Out On Low
Outdoor Air Temperature
1
11 Flashes
Compressors Locked Out Because The
Economizer Is Using Free Cooling
1
12 Flashes
Fan Overload Switch Trip
13 Flashes
Compressor Held Off Due To Low Voltage1
14 Flashes
EEPROM Storage Failure (Control Failure)
OFF
No Power or Control Failure