Troubleshooting & Solutions Guide 4th Generation ® DIY E Star™ Series Due to updates and constantly improving performance, the information and instructions within this manual are subject to change without notice. Please visit www.mrcool.com/documentation to ensure you have the latest version of this manual.
Troubleshooting Contents 1. Safety Caution .......................................................................................................3 2. General Troubleshooting ......................................................................................4 3. Complain Record Form..........................................................................................6 4. Information Inquiry ...............................................................................................8 5.
Troubleshooting Contents 7.8 PC 08 (Overload current protection diagnosis and solution) .................... 28 7.9 PC 00 (IPM malfunction or IGBT over-strong current protection diagnosis and solution) ............................................................................................. 29 7.10 PC 01 (Over voltage or too low voltage protection diag. and solution)...... 30 7.11 PC 02 (High temperature protection of IPM module or high pressure protection diagnosis and solution) ..................
1. Safety Caution WARNING Be sure to turn off all power supplies or disconnect all wires to avoid electric shock. While checking indoor/outdoor PCB, please equip oneself with anti-static gloves or wrist strap to avoid damage to the board. WARNING Electricity remains in capacitors even when the power supply is off. Ensure the capacitors are fully discharged before troubleshooting. Test the voltage between P and N on back of the main PCB with multimeter.
2. General Troubleshooting 2.1 Error Display (Indoor Unit) When the indoor unit encounters a recognized error, the operation lamp will flash in a corresponding series, the timer lamp may turn on or begin flashing, and an error code will be displayed.
For other errors: The display board may show a garbled code or a code undefined by the service manual. Ensure that this code is not a temperature reading. Troubleshooting: Test the unit using the remote control. If the unit does not respond to the remote, the indoor PCB requires replacement. If the unit responds, the display board requires replacement. LED flash frequency: ... ... 2.2 Error Display (For Some Outdoor Units) There are 2 LED lights (RED color and GREEN color) welded in outdoor main board.
3. Complain Record Form Complain Record Form Request No.: Date: Installation Date: Service Date: Customer Information Name Telephone No. Home Address Email Product Information Indoor Unit Model Outdoor Unit Model Serial No. of indoor unit Serial No.
Parameter Checking information by Remote controller Displaying code Displaying code meaning T1 Room temperature T2 Indoor coil temperature T3 Outdoor coil temperature T4 Ambient temperature Tb Outlet temperature of indoor coil TP Discharge temperature TH Sunction temperature FT Targeted Frequency Fr Actual Frequency IF Indoor fan speed OF Outdoor fan speed LA EXV opening steps CT Compressor continuous running time ST Causes of compressor stop.
4. Information Inquiry • To enter information inquiry status, complete the following procedure within ten seconds: • Press LED (or DO NOT DISTURB) 3 times. • Press SWING (or AIR DIRECTION) 3 times. • Finish 1 and 2 within 10 seconds, you will hear beeps for two seconds, which means the unit goes into parameter checking mode. • Use the LED (or DO NOT DISTURB) and SWING (or AIR DIRECTION) buttons to cycle through information displayed.
Displayed code Displayed value Explanation T1 Room temperature T2 Indoor coil temperature T3 Outdoor coil temperature T4 Ambient temperature Tb Meaning Additional Notes 1. All displayed temperatures use actual values. -1F,-1E,-1d,-1c,- -25,-24,-23,-22, 1b,-1A -21,-20 2. All temperatures are displayed in °C regardless of remote used.
Displayed code Explanation Displayed value Meaning Additional Notes A0 A1 0 1 2 3 0-FF 4 5 6 L Reserved 2-28 5-20 - 5-25 A U T A 5 T Troubleshooting 10 -
5. Error Diagnosis and Troubleshooting Without Error Code WARNING Be sure to turn off unit before any maintenance to prevent damage or injury. 5.1 Remote maintenance SUGGESTION: When troubles occur, please check the following points with customers before field maintenance. No.
5.
Loose connec�ons Faulty transformer The voltage is too high or too low The remote control is powered off Broken remote control Dirty air filter Dirty condenser fins The se�ng temperature is higher/lower than the room's(cooling/hea�ng) The ambient temperature is too high/low when the mode is cooling/hea�ng Fan mode SILENCE func�on is ac�vated (op�onal func�on) Fros�ng and defros�ng frequently Inspect connec�ons - �ghten Change the transformer Test voltage Replace the ba�ery of the remote control Replace th
Heavy load condi�on Loosen hold down bolts and / or screws Bad airproof The air inlet or outlet of either unit is blocked Interference from cell phone towers and remote boosters Shipping plates remain a�ached Tighten bolts or screws Close all the windows and doors Remove the obstacles Reconnect the power or press ON/OFF bu�on on remote control to restart opera�on Remove them Others Check heat load 1.
Low suc�on pressure High suc�on pressure Unit runs con�nuously but insufficient cooling Too cool Horizontal louver can not revolve Compressor is noisy Test method / remedy Troubleshooting 15 Low voltage Test voltage Shorted or grounded fan motor Faulty magne�c contactor for fan Check resistance with mul�meter Faulty magne�c contactor for compressor Test con�nuity of coil & contacts Test con�nuity of coil & contacts Faulty stepping motor Shorted or open capacitor Check capacitor with tester Sho
Evaporator (indoor) fan will not start Unit runs, but shortly stops Condenser (Outdoor) fan will not start Compressor short-cycles due to overload High discharge pressure Low discharge pressure High suc�on pressure Low suc�on pressure Unit runs con�nuously but insufficient cooling Too cool Compressor is noisy Horizontal louver can not revolve Test method / remedy Troubleshooting 16 Air or incompressible gas in refrigerant cycle Short cycling of condensing air High temperature condensing medium In
6. Quick Maintenance by Error Code If you do not have the time to test which specific parts are faulty, you can directly change the required parts according the error code. You can find the parts to replace by error code in the following table.
7. Troubleshooting by Error Code 7.1 EH 00 / EC 51 (EEPROM parameter error diagnosis and solution) Description: Indoor or outdoor PCB main chip does not receive feedback from EEPROM chip. Recommended parts to prepare: • Indoor PCB • Outdoor PCB Troubleshooting and repair: Shut off the power supply and turn it on 2 minutes later. Is it still displaying the error code? NO The unit is operating normally. YES Replace the indoor main PCB(EH 00) /outdoor main PCB (EC 51).
7.2 EL 01 (Indoor and outdoor unit communication error diagnosis and solution) Description: Indoor unit can not communicate with outdoor unit Recommended parts to prepare: • Indoor PCB • Outdoor PCB • Short-circuited component Troubleshooting and repair: Power off, then restart the unit after 2 minutes.
Remarks: • Use a multimeter to test the DC voltage between 2 port (or S or L2 port) and 3 port (or N or S port) of outdoor unit. The red pin of multimeter connects with 2 port (or S or L2 port) while the black pin is for 3 port (or N or S port) . • When AC is normal running, the voltage is moving alternately as positive values and negative values • If the outdoor unit has malfunction, the voltage has always been the positive value.
7.3 EH 02 (Zero crossing detection error diagnosis and solution) Description: When PCB does not receive zero crossing signal feedback for 4 minutes or the zero crossing signal time interval is abnormal. Recommended parts to prepare: • Connection wires • PCB Troubleshooting and repair: Check the connections and power supply. Is it normal? NO Correct the connections. Turn on the unit when the power supply is good. YES Indoor main PCB is defective. Replace indoor main PCB.
7.4 EH 03 / EC 07 (Fan speed is operating outside of normal range diagnosis and solution) Description: When indoor / outdoor fan speed keeps too low or too high for a certain time, the LED displays the failure code and the AC turns off. Recommended parts to prepare: • Connection wires • Fan assembly • Fan motor • PCB Troubleshooting and repair: Power off, then restart the unit after 2 minutes.
Index: 1. Indoor or Outdoor DC Fan Motor(control chip is in fan motor) Power on and when the unit is in standby, measure the voltage of pin1-pin3, pin4-pin3 in fan motor connector. If the value of the voltage is not in the range showing in below table, the PCB must has problems and need to be replaced. • DC motor voltage input and output (voltage: 220-240V~): No. Color Signal Voltage 1 Red Vs/Vm 280V~380V 2 --- --- --- 3 Black GND 0V 4 White Vcc 14-17.5V 5 Yellow Vsp 0~5.
3. Indoor AC Fan Motor Power on and set the unit running in fan mode at high fan speed. After running for 15 seconds, measure the voltage of pin1 and pin2. If the value of the voltage is less than 100V(208~240V power supply) or 50V (115V power supply), the PCB must has problems and need to be replaced.
7.5 EH 60/EH 61/EC 53/EC 52/EC 54/EC 56 (Open circuit or short circuit of temperature sensor diagnosis and solution) Description: If the sampling voltage is lower than 0.06V or higher than 4.94V, the LED displays the failure code. Recommended parts to prepare: • Connection wires • Sensors • PCB Troubleshooting and repair: Check the connection between temperature sensor and PCB . Is it properly wired? NO Ensure proper connections . YES Measure the resistance value of the sensor.
Note: For certain models, outdoor PCB could not be removed separately. In this case, the outdoor electric control box should be replaced as a whole. This picture and the value are only for reference, actual appearance and value may vary 7.6 EH 0b (Indoor PCB / Display board communication error diagnosis and solution) Description: Indoor PCB does not receive feedback from the display board.
7.7 EL 0C (Refrigerant Leakage Detection diagnosis and solution) Description: Define the evaporator coil temperature T2 of the compressor just starts running as Tcool. In the beginning 5 minutes after the compressor starts up, if T2
7.8 PC 08 (Overload current protection diagnosis and solution) Description: An abnormal current rise is detected by checking the specified current detection circuit. Recommended parts to prepare: • Outdoor PCB • Connection wires • Compressor Troubleshooting and repair: Check the power supply. Is it in working order? NO Stop the unit. YES Check systemfor blockages. Do any exist? Clear the blockage. Yes No Check the compressor resistance values .
7.9 PC 00(IPM malfunction or IGBT over-strong current protection diagnosis and solution) Description: When the voltage signal the IPM sends to the compressor drive chip is abnormal, the LED displays the failure code and the AC turns off. Recommended parts to prepare: • Connection wires • IPM module board • Outdoor fan assembly • Compressor • Outdoor PCB Troubleshooting and repair: Check the wiring between PCB and compressor .
7.10 PC 01(Over voltage or too low voltage protection diagnosis and solution) Description: Abnormal increases or decreases in voltage are detected by checking the specified voltage detection circuit. Recommended parts to prepare: • Power supply wires • IPM module board • PCB • Reactor Troubleshooting and repair: Check the power supply. Is it in working order? NO Turn off the unit. YES Check the connections and wires . Are they in working order? Ensure proper connections or replace the wires.
7.11 PC 02(High temperature protection of IPM module or High pressure protection diagnosis and solution) Description: If the temperature of IPM module is higher than a certain value, the LED displays the failure code. For some models with high pressure switch, outdoor pressure switch cut off the system because high pressure is higher than 4.4 MPa, the LED displays the failure code.
High High pressure pressure protection protection Are Are the the high high pressure pressure switch switch and and main main control control boar boar wired wired correctly? correctly? No Connect Connect high high pressure pressure switch switch and and main mian control control board board Yes Is Is the the high high pressure pressure protector protector broken? broken? Method: Method: Disconnect Disconnect the the plug plug..
7.12 PC 04(Inverter compressor drive error diagnosis and solution) Description: An abnormal inverter compressor drive is detected by a special detection circuit, including communication signal detection, voltage detection, compressor rotation speed signal detection and so on. Recommended parts to prepare: • Connection wires • IPM module board • Outdoor fan assembly • Compressor • Outdoor PCB Troubleshooting and repair: Check the wiring between the PCB and compressor .
7.13 PC 03(Low pressure protection diagnosis and solution) Description: Outdoor pressure switch cut off the system because low pressure is lower than 0.13 MPa, the LED displays the failure code.
Low Low pressure pressure protection protection Are Are the the low low pressure pressure protector protector and and main main control control board board wired wired properly? properly? No Reconnect Reconnect the the low low pressure pressure protector protector and and main main control control board board Yes Is Is the the low low pressure pressure protector protector broken? broken? Method: Method: Disconnect Disconnect the the plug plug..
8. Check Procedures 8.1 Temperature Sensor Check WARNING Be sure to turn off all power supplies or disconnect all wires to avoid electric shock. Operate after compressor and coil have returned to normal temperature in case of injury. 1. Disconnect the temperature sensor from PCB (Refer to Chapter 5 & 6. Indoor & Outdoor Unit Disassembly). 2. Measure the resistance value of the sensor using a multi-meter. 3. Check corresponding temperature sensor resistance value table (Refer to Chapter 8. Appendix).
Resistance Value ASM135D23UFZ ATQ420D1UMU ASN98D22UFZ ATF235D22UMT ATQ360D1UMU 1.75Ω 0.37Ω 1.57Ω 0.75Ω 0.37Ω Blue-Red Blue-Black Red-Black Resistance Value ATM115D43UFZ2 ATF250D22UMT ATF310D43UMT KSK103D33UEZ3(YJ) ASM98D32UFZ 1.87Ω 0.75Ω 0.65Ω 2.13Ω 2.2Ω ASN140D21UFZ ASK89D29UEZD KSN140D21UFZ KTM240D57UMT KSK103D33UEZ3 1.28Ω 1.99Ω 1.28Ω 0.62Ω 2.
Note: The picture and the value are only for reference, actual condition and specific value may vary. 8.3 IPM Continuity Check WARNING Electricity remains in capacitors even when the power supply is off. Ensure the capacitors are fully discharged before troubleshooting. 1. Turn off outdoor unit and disconnect power supply. 2. Discharge electrolytic capacitors and ensure all energy-storage unit has been discharged. 3. Disassemble outdoor PCB or disassemble IPM board. 4.
Note: The picture and the value are only for reference, actual condition and specific value may vary.
8.4 4-way Valve Check 1. Power on, use a digital tester to measure the voltage, when the unit operates in cooling, it is 0V. When the unit operates in heating, it is about 230VAC. If the value of the voltage is not in the range, the PCB must have problems and need to be replaced. 2 Turn off the power, use a digital tester to measure the resistance. The value should be 1.8~2.5 KΩ.
8.5 EXV Check WARNING Electricity remains in capacitors even when the power supply is off. Ensure the capacitors are fully discharged before troubleshooting. 1. Disconnect the connector from outdoor PCB. 2. Measure the resistance value of each winding using a multi-meter. 3. Check the resistance value of each winding in the following table.
Appendix Contents i) Temperature Sensor Resistance Value Table for T1, T2, T3, and T4 (°C – K) ......2 ii) Temperature Sensor Resistance Value Table for TP (for some units) (°C --K) ....3 iii) Pressure On Service Port .......................................................................................
i) Temperature Sensor Resistance Value Table for T1,T2,T3 and T4 (°C – K) °C °F K Ohm °C °F K Ohm °C °F K Ohm °C °F K Ohm -20 -4 115.266 20 68 12.6431 60 140 2.35774 100 212 0.62973 -19 -2 108.146 21 70 12.0561 61 142 2.27249 101 214 0.61148 -18 0 101.517 22 72 11.5 62 144 2.19073 102 216 0.59386 -17 1 96.3423 23 73 10.9731 63 145 2.11241 103 217 0.57683 -16 3 89.5865 24 75 10.4736 64 147 2.03732 104 219 0.56038 -15 5 84.
ii) Temperature Sensor Resistance Value Table for TP (for some units) (°C --K) °C °F K Ohm °C °F K Ohm °C °F K Ohm °C °F K Ohm °C °F K Ohm °C °F K Ohm °C °F K Ohm °C °F K Ohm -20 -4 542.7 20 68 68.66 60 140 13.59 100 212 3.702 -19 -2 511.9 21 70 65.62 61 142 13.11 101 214 3.595 -18 0 483 22 72 62.73 62 144 12.65 102 216 3.492 -17 1 455.9 23 73 59.98 63 145 12.21 103 217 3.392 -16 3 430.5 24 75 57.37 64 147 11.79 104 219 3.
iii) Pressure On Service Port Cooling chart (R410A): °F(°C) BAR PSI MPa ODU(DB) 0(-17) 5(-15) 15 (-9.44) 45 (7.22) 75 (23.89) 85 (29.44) 95 (35) 105 (40.56) 115 (46.11) 120 (48.89) 70/59 (21.11/15) 6.4 6.5 7.3 8.0 8.2 7.8 8.1 8.6 10.1 10.6 75/63 (23.89/17.22) 6.7 6.8 7.9 8.6 8.6 8.3 8.7 9.1 10.7 11.2 80/67 (26.67/19.44) 7.1 7.2 8.5 9.5 9.3 8.9 9.1 9.6 11.2 11.9 90/73 (32.22/22.78) 7.7 7.8 9.6 10.5 10.3 9.5 10.0 10.6 12.4 13.0 70/59 (21.
Heating chart (R410A): °F(°C) BAR PSI MPa ODU(DB/WB) 57/53 (13.89/11.67) 47/43 (8.33/6.11) 37/33 (2.78/0.56) 27/23 (-2.78/-5) 17/13 (-8.33/10.56) 0/-2 (-17/-19) -17/-18 (-27/-28) 55(12.78) 30.3 28.5 25.3 22.8 20.8 18.5 16.5 65(18.33) 32.5 30.0 26.6 25.4 23.3 20.5 19.0 75(23.89) 33.8 31.5 27.8 26.3 24.9 21.5 20.0 55(12.78) 439 413 367 330 302 268 239 65(18.33) 471 435 386 368 339 297 276 IDU(DB) 75(23.89) 489 457 403 381 362 312 290 55(12.78) 3.
Cooling chart (R22): °F(°C) BAR PSI MPa ODU(DB) 0(-17) 5(-15) 15 (-9.44) 45 (7.22) 75 (23.89) 85 (29.44) 95 (35) 105 (40.56) 115 (46.11) 120 (48.89) 70/59 (21.11/15) 4.0 4.1 4.6 5.0 5.1 4.9 5.1 5.4 6.3 6.6 75/63 (23.89/17.22) 4.2 4.3 4.9 5.4 5.4 5.2 5.4 5.7 6.7 7.0 80/67 (26.67/19.44) 4.4 4.5 5.3 5.9 5.8 5.6 5.7 6.0 7.0 7.4 90/73 (32.22/22.78) 4.8 4.9 6.0 6.6 6.4 5.9 6.3 6.6 7.8 8.1 70/59 (21.
Heating chart (R22): °F(°C) ODU(DB/WB) 57/53 (13.89/11.67) 47/43 (8.33/6.11) 37/33 (2.78/0.56) 27/23 (-2.78/-5) 17/13 (-8.33/10.56) 0/-2 (-17/-19) -17/-18 (-27/-28) 55(12.78) 18.9 17.8 15.8 14.3 13.0 11.6 10.3 65(18.33) 20.3 18.8 16.6 15.9 14.6 12.8 11.9 IDU(DB) BAR PSI MPa 75(23.89) 21.1 19.7 17.3 16.4 15.6 13.4 12.5 55(12.78) 274 258 229 207 189 168 149 65(18.33) 294 273 241 231 212 186 172.6 75(23.89) 306 286 251 238 226 194 181 55(12.78) 1.
Cooling chart (R32): °F(°C) BAR PSI MPa ODU(DB) 0(-17) 5(-15) 15 (-9.44) 45 (7.22) 75 (23.89) 85 (29.44) 95 (35) 105 (40.56) 115 (46.11) 120 (48.89) 70/59 (21.11/15) 6.5 6.6 7.4 8.2 8.4 8.0 8.3 8.8 10.3 10.8 75/63 (23.89/17.22) 6.8 6.9 8.1 8.8 8.8 8.5 8.9 9.3 10.9 11.4 IDU(DB/WB) 80/67 (26.67/19.44) 7.2 7.3 8.7 9.7 9.5 9.1 9.3 9.8 11.4 12.1 90/73 (32.22/22.78) 7.9 8.0 9.8 10.7 10.5 9.7 10.2 10.8 12.6 13.3 70/59 (21.
Heating chart (R32): °F(°C) ODU(DB/WB) 57/53 (13.89/11.67) 47/43 (8.33/6.11) 37/33 (2.78/0.56) 27/23 (-2.78/-5) 17/13 (-8.33/10.56) 0/-2 (-17/-19) -17/-18 (-27/-28) 55(12.78) 30.9 29.1 25.8 23.3 21.2 18.9 16.8 65(18.33) 33.2 30.6 27.1 25.9 23.8 20.9 19.4 IDU(DB) BAR PSI MPa 75(23.89) 34.5 32.1 28.4 26.8 25.4 21.9 20.4 55(12.78) 448 421 374 337 308 273 244 65(18.33) 480 444 394 375 346 303 282 75(23.89) 499 466 411 389 369 318 296 55(12.78) 3.
System Pressure Table-R22 Pressure Temperature Pressure Temperature Kpa bar PSI °C °F Kpa bar PSI °C °F 100 1 14.5 -41.091 -41.964 1600 16 232 41.748 107.146 150 1.5 21.75 -32.077 -25.739 1650 16.5 239.25 43.029 109.452 200 2 29 -25.177 -13.319 1700 17 246.5 44.281 111.706 250 2.5 36.25 -19.508 -3.114 1750 17.5 253.75 45.506 113.911 300 3 43.5 -14.654 5.623 1800 18 261 46.706 116.071 350 3.5 50.75 -10.384 13.309 1850 18.5 268.25 47.
System Pressure Table-R410A Pressure Temperature Pressure Temperature Kpa bar PSI °C °F Kpa bar PSI °C °F 100 1 14.5 -51.623 -60.921 2350 23.5 340.75 38.817 101.871 150 1.5 21.75 -43.327 -45.989 2400 24 348 39.68 103.424 200 2 29 -36.992 -34.586 2450 24.5 355.25 40.531 104.956 250 2.5 36.25 -31.795 -25.231 2500 25 362.5 41.368 106.462 300 3 43.5 -27.351 -17.232 2550 25.5 369.75 42.192 107.946 350 3.5 50.75 -23.448 -10.
System Pressure Table-R32 Pressure Temperature Pressure Temperature Kpa bar PSI °C °F Kpa bar PSI °C °F 100 1 14.5 -51.909 -61.436 1850 18.5 268.25 28.425 83.165 150 1.5 21.75 -43.635 -46.543 1900 19 275.5 29.447 85.005 200 2 29 -37.323 -35.181 1950 19.5 282.75 30.448 86.806 250 2.5 36.25 -32.15 -25.87 2000 20 290 31.431 88.576 300 3 43.5 -27.731 -17.916 2050 20.5 297.25 32.395 90.311 350 3.5 50.75 -23.85 -10.93 2100 21 304.5 33.
4th Generation DIY® E Star™ Series
