898150-UIM-B-0113
Johnson Controls Unitary Products
27
F2
Indoor coil sensor (RT2)
open or short circuited
Cooling and dehumidification modes will
continue to operate as well as indoor fan.
Unit will not operate in heating mode.
• Check sensor to ensure that it is in
acceptable range.
• Check sensor for proper resistance.
• Replace sensor if shorted, open or out-
of-calibration.
F3
Outdoor ambient sensor (RT4)
open or short circuit
All system functions are terminated except
indoor fan.
F4
Outdoor coil sensor (RT3)
open or short circuit
F5
Discharge line sensor (RT5) error
All system functions will continue to run for
3 minutes, then terminate. Indoor fan will
continue to run.
F6
Compressor overload limit issue
Normal operational state with compressor
speed automatically adjust for operational
conditions. System will continue to opera-
tion at reduced compressor speed until
issue is corrected.
• Check outdoor ambient air temperature.
Could be too high.
• Check for locked compressor rotor.
• Check for blocked refrigeration circuit
(capillary tubes for example).
• Check for blocked or restricted outdoor
air flow. Clear, if necessary.
• Check for low refrigerant charge.
F8
High current limit issue
System will continue to operate at reduce
compressor speed until issue is corrected.
Check for low or high input voltage. Cor-
rect if necessary. Could be too high.
F9
Discharge line temperature too high
Check discharge line temperature. Correct
if to high.
HC
Power factor correction protection
Refer to the ProficienTECH Ductless Splits
Technical Training Manual.
HE
Compressor demagnetization
protection
Compressor has exceeded peak demag-
netization current (41A), reduced fre-
quency. Compressor running at reduced
frequency.
De-energize system and restart.
H0
Heating mode anti-high
temperature protection
Refer to the ProficienTECH Ductless Splits
Technical Training Manual.
H1
Defrosting (heat pump only)
Normal operation
Normal defrost operation.
H2 Electrostatic
protection
System protection feature. All system
functions are terminated except indoor fan.
Excessive electrostatic charge present.
Correct, if possible.
H3
Compressor overload protection
sensor (CT1,2) malfunction.
All system functions are terminated except
indoor fan.
• Check for proper wiring connections and
loose wires at outdoor control (CT1, 2) in-
put plug.
• Check for continuity across overload pro-
tection sensor terminals mounted at top of
compressor.
H4
Compressor high
temperature protection
All system functions are terminated except
indoor fan.
• Check for proper wiring connections and
loose wires at outdoor control (CT1, 2) in-
put plug.
• Check for continuity across overload pro-
tection sensor terminals mounted at top of
compressor.
H5
Intelligent Power Module
(IPM) module protection
All system functions are terminated except
indoor fan.
This can be caused by any of the follow-
ing:
• Loss of cooling to the heat sink
• Low voltage.
• High ambient temperature
• Loose screws fastening the outdoor con-
trol to the heat sink
TABLE 12:
Error Codes
Indoor Character
Display
System Status
Troubleshooting for
Possible Causes
