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Protection code & location |
Error description |
Recommended action |
E0 |
Power phase loss or wrong |
Check the power supply wire sequence. |
EF |
External device protection |
Check field installed shutdown device (CN7/CN31, CN28/CN30) |
E5 (CN40) |
Evaporator A coil temperature sensor fault |
Replace the T2-A temperature sensor. |
E6 (CN41) |
Evaporator B coil temperature sensor fault |
Replace the T2-B temperature sensor. |
E9 (CN40) |
Indoor temperature sensor fault |
Replace the T1 temperature sensor. |
EA (CN5) |
Outdoor temperature sensor fault |
Replace the T4 temperature sensor. |
Eb |
Thermostat output signal fault |
Correct thermostat operation. (Invalid call) |
EC |
Error selection of model dialing code |
Check whether the unit dip switches SW1-3/SW1-4 is consistent with the nameplate. |
PE (CN13) |
System A high pressure switch protection |
Check whether the outdoor fan is running normally. |
Check whether the outdoor panel is installed. |
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Check whether the condenser A is dirty. |
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PF (CN13) |
System B high pressure switch protection |
Check whether the outdoor fan is running normally. |
Check whether the outdoor panel is installed. |
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Check whether the condenser B is dirty. |
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P3 (CN12) |
Indoor fan overload protection or three-phase protector protection |
Check whether the three-phase protector dial code is consistent with the wiring nameplate. |
Check airflow. |
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Check whether the indoor motor XP7 is open. |
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P4 (CN8) |
System A Low-pressure switch protection or high discharge temperature protection |
Check system A for leak or refrigeration circuit is blocked. |
P5 (CN8) |
System B Low pressure switch protection or high discharge temperature protection |
Check system B for leakage or refrigeration circuit is blocked. |
Pb (CN42) |
Outdoor DC motor module protection |
Check whether the outdoor motor dial code SW1-2 is consistent with the wiring nameplate. |
Check whether the fan blade is stuck. |
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Check the fan drive board, if there is a red light flashing, replace the drive board. |
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Measure the motor resistance of any two phases, the normal resistance of each two phases is ohmic level, otherwise replace the DC motor. |
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PC (CN40) |
Poor refrigeration capacity, compressor A out of operation, Evap. Sensor has been below 36° F for 5+ min. Resets at 46° F |
Check airflow. |
Check indoor the fan wheel / motor |
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Check whether the filter is dirty. |
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Check the system A charge or refrigeration circuit is blocked. |
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Pd CN41) |
Poor refrigeration capacity, compressor B out of operation, Evap. Sensor has been below 36° F for 5+ min. Resets at 46° F |
Check airflow |
Check the fan wheel / motor. |
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Check whether the filter is dirty. |
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Check the system B charge or refrigeration circuit is blocked. |
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Ph (CN5) |
Outdoor temperature protection |
Check whether the outdoor temperature is below 5° F otherwise replace the T4 temperature sensor. |
PA (CN34) |
VFD protection |
Correct VFD connection or replace the VFD. (VFD not communicating with board) |
H9 |
Pb code 10 times within 120 minutes |
Same with Pb code. |
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Error Code Notes:
– – (Unit is in standby)
10 (Unit is running)
It looks like Eb and P3 codes require a power reset to clear.
Eb can be caused by a Y1 without a G, W1 without a G (on electric heat units), Y2 before Y1, W2 without or before W1, Heat and Cool call at the same time.
LPC and HPC are Auto Reset. (The error on the display will clear in 3 minutes) then the circuit will come on according to the board time delays.
Opening E-Stop (CN43) gives a – – (Standby) then the board powers off.
Cutting jumper JP1, then an open field installed contact wired to CN7 and CN31 gives you an EF.
Cutting jumper JP2, then an open field installed contact wired to CN30 and CN28 gives you an EF.
Temp sensor errors cut the power to thermostat “R”
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WARNING:
Information in this article is intended for use by individuals possessing adequate backgrounds of electrical and mechanical experience and who comply with all federal, state, and local laws, rules, orders, or regulations related to the installation, service, or repair of a heating or central air conditioning product. Any attempt to install, service, or repair a heating or central air conditioning product may result in personal injury and/or property damage. The manufacturer or seller cannot be responsible for the interpretation of the information contained herein, nor can it assume any liability in connection with its use.