035-17311-002-A-0803
40
Unitary Products Group
TABLE 37: 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
*
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
*
11 Flashes
Compressors Locked Out Because The
Economizer Is Using Free Cooling
*
12 Flashes
Fan Overload Switch Trip - Not Applicable On This Unit *
13 Flashes
Compressor Held Off Due To Low Voltage*
14 Flashes
EEPROM Storage Failure (Control Failure)
OFF
No Power or Control Failure
*.
These flash codes do not represent alarms.
FIGURE 24 - BASIC TROUBLESHOOTING FLOWCHART
Monitor
Monitored
Systems
Problem?
Call for
Cooling?
Call for
Heating?
Call for
Heat
Yes
No
No
No
Call for 1st
Stage
Cooling
First
Stage?
Call for 2nd
Stage
Cooling
Yes
Yes
Loss of
Call for
Heating?
Loss of Call
for Cooling?
Heat Off
Cool Off
Yes
Yes
No
Call for
ID Blower?
Fan off
>10 secs?
Energize ID
Blower Motor
Yes
Yes
No
Programming?
Program
Unit
Control
Board
Trip/Failure
No
No
Lossof Call
for ID Blower?
Turn off ID
Blower Motor
Fan on
>30 secs?
Yes
No
Yes
No
No
Yes
Yes
No
