INDOOR UNIT ERROR CODES
TABLE 12: Error Codes
Indoor Character
RT1 room temperature sensor
b5
malfunction
RT2 coil temperature sensor
b7
malfunction
Indoor control jumper is
C5
missing (labeled JUMP)
dd
Pre-operation function
dn
Pre-operation function error
Intelligent Power Module
EE
protection limit
Intelligent Power
EU
Module protection limit
E1
System high pressure
E2
Indoor coil freeze protection
E3
Low pressure protection
Johnson Controls Unitary Products
Display
Cooling and dehumidification modes will
continue to operate as well as indoor fan.
Unit will not operate in heating mode.
All system functions are terminated.
When unit is set to cooling mode and set
point is 86ºF (30ºC), press the remote -
and + button in the following sequence ( -
+ - + - +) for three seconds to place the
unit in pre-operation mode. This cooling
operation with the indoor fan off and dd is
displayed on indoor unit.
If during pre-operation mode, if it is deter-
mine that the unit is wired incorrectly or the
expansion valve has malfunction this code
will display.
System will continue to run; however at
reduced compressor speed until issue is
corrected.
All system functions are terminated.
All system functions are terminated except
indoor fan.
All system functions are terminated except
indoor fan. The indoor coil sensor (RT2)
monitors the coil temperature continu-
ously. If coil temperature drops below
30.2ºF (-1ºC), the compressor and the out-
door fan (30 seconds later) are switched
off. Condition is cleared when indoor coil
temperature rises above 42.8ºF (6ºC) and
the compressor has been off for a mini-
mum of three minutes.
All system functions are terminated except
indoor fan.
System Status
898150-UIM-B-0113
Troubleshooting for
Possible Causes
• Check sensor to ensure that it is in
acceptable range.
• Check sensor for proper resistance.
• Replace sensor if shorted, open or out-
of-calibration.
Check indoor control jumper connections
and replace jumper, if missing.
Normal system operation
• Check expansion valve • Check wiring.
Replace outdoor control.
Intelligent Power Module protection limit
error can result from any of the following:
• Loss of cooling to the heat sink
• Low voltage
• High ambient temperature
• Loose screws fastening the outdoor con-
trol to the heat sink
Check all and correct, if necessary, refer to
the ProficienTECH Ductless Splits Techni-
cal Training Manual.
• Outdoor unit high pressure switch is
disconnected or has malfunctioned.
• Verify connection to outdoor control. If
connection is verified and system is still
displaying E1, re-place high pressure
sensor.
• Check for restricted indoor airflow and
change filter, if necessary.
• Check for restricted refrigerant flow.
• Check for low outdoor ambient tempera-
ture or low indoor system load.
• Check for proper clearances around
outdoor unit.
• Check outdoor coil for and clean, if
necessary.
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