Daikin VRV IV+ User manual

Service manual
VRV IV+ Heat Recovery
REYQ8U7Y1B
REYQ10U7Y1B
REYQ12U7Y1B
REYQ14U7Y1B
REYQ16U7Y1B
REYQ18U7Y1B
REYQ20U7Y1B
REMQ5U7Y1B

Disclaimer
Service manual
2
REYQ8~20+REMQ5U7Y1B
VRV IV+ Heat Recovery
ESIE18-15B – 2020.05
Disclaimer
The present publication is drawn up by way of information only and does not constitute an offer binding upon
Daikin Europe N.V.. Daikin Europe N.V. has compiled the content of this publication to the best of its knowledge.
No express or implied warranty is given for the completeness, accuracy, reliability or fitness for particular purpose
of its content and the products and services presented therein. Specifications are subject to change without prior
notice. Daikin Europe N.V. explicitly rejects any liability for any direct or indirect damage, in the broadest sense,
arising from or related to the use and/or interpretation of this publication. All content is copyrighted by Daikin
Europe N.V..

Version log
Service manual
3
REYQ8~20+REMQ5U7Y1B
VRV IV+ Heat Recovery
ESIE18-15B – 2020.05
Version log
Version code Description Date
ESIE18-15 Document release January 2020
ESIE18-15A Document release April 2020
ESIE18-15B See below May 2020
The following updates have been applied to the Service Manual:
•Crankcase heater – Check procedures: Electrical check updated.
•Inverter PCB – Repair procedures: Remove + install procedures updated.

Table of contents
Service manual
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REYQ8~20+REMQ5U7Y1B
VRV IV+ Heat Recovery
ESIE18-15B – 2020.05
Table of contents
1 General operation 10
2 Troubleshooting 14
2.1 To access push buttons and 7-segment display............................................................................................................. 14
2.2 To retrieve error codes and check error history ............................................................................................................ 14
2.2.1 Via the indoor unit remote controller BRC1H ............................................................................................... 14
2.2.2 Via the outdoor unit ....................................................................................................................................... 16
2.2.3 Via the wired remote control BRC1E ............................................................................................................. 17
2.2.4 Via the wireless controller BRC4/7................................................................................................................. 19
2.2.5 Via the wired remote control BRC1D............................................................................................................. 20
2.2.6 Via service monitoring tool ............................................................................................................................ 21
2.3 Error based troubleshooting........................................................................................................................................... 22
2.3.1 A3-01 – Multi BS Unit PCB Abnormality......................................................................................................... 22
2.3.2 E1-01 – Outdoor unit main PCB A1P error .................................................................................................... 22
2.3.3 E1-02 – Outdoor unit main PCB A1P error .................................................................................................... 23
2.3.4 E2-01-02-03 – Current leak detection ........................................................................................................... 23
2.3.5 E2-06-07-08 – Open circuit on earth leakage detection core....................................................................... 24
2.3.6 E3-01-03-05 – Actuation of high pressure switch ......................................................................................... 25
2.3.7 E3-02-04-06 – High pressure error ................................................................................................................ 27
2.3.8 E3-07 – High pressure switch reset error ...................................................................................................... 28
2.3.9 E3-13-14-15 – Liquid stop valve check error ................................................................................................. 29
2.3.10 E3-18 – Actuation of high pressure switch during test run........................................................................... 30
2.3.11 E3-20-21-22 – Jumper open on main PCB ..................................................................................................... 31
2.3.12 E4-01-02-03 – Low pressure error ................................................................................................................. 31
2.3.13 E5-01-02-03 – Compressor overload/Motor Lock Error (M1C) .................................................................... 33
2.3.14 E5-07-08-09 – Compressor overload/Motor Lock Error (M2C) .................................................................... 34
2.3.15 E6-17-19-21 – Inverter overcurrent error ..................................................................................................... 35
2.3.16 E6-18-20-22 – Inverter overcurrent error ..................................................................................................... 37
2.3.17 E7-01-13-25 – Outdoor unit fan motor M1F error........................................................................................ 38
2.3.18 E7-02-14-26 – Outdoor unit fan motor M2F error........................................................................................ 39
2.3.19 E7-05-17-29 – Outdoor unit fan motor M1F overcurrent error ................................................................... 39
2.3.20 E7-06-18-30 – Outdoor unit fan motor M2F overcurrent error ................................................................... 40
2.3.21 E7-09-21-33 – Fan inverter PCB A4P (integrated power module) overheated ............................................ 41
2.3.22 E7-10-22-34 – Fan inverter PCB A7P (integrated power module) overheated ............................................ 42
2.3.23 E9-01-05-08 – Electronic expansion valve Y1E malfunction ......................................................................... 43
2.3.24 E9-03-06-09 – Electronic expansion valve Y2E malfunction ......................................................................... 44
2.3.25 E9-04-07-10 – Electronic expansion valve Y3E abnormality ......................................................................... 45
2.3.26 E9-20-21-22 – Electronic Expansion Valve (Y1E) failure................................................................................ 46
2.3.27 E9-23-24-25 – Electronic expansion valve (Y2E) failure ................................................................................ 47
2.3.28 E9-26-27-28 – Electronic expansion valve (Y4E) malfunction....................................................................... 49
2.3.29 E9-29-34-39 – Electronic expansion valve (Y5E) malfunction....................................................................... 50
2.3.30 E9-31-36-41 – Electronic expansion valve (Y6E ) malfunction ...................................................................... 51
2.3.31 E9-44-45-46 – Electronic expansion valve (Y3E) failure ................................................................................ 52
2.3.32 E9-48-49-50 – Electronic expansion valve overcurrent error ....................................................................... 53
2.3.33 E9-51-52-53 – Electronic expansion valve thermal cutting error ................................................................. 55
2.3.34 E9-54-55-56 – Electronic expansion valve defective circuit.......................................................................... 56
2.3.35 F3-01-03-05 – Compressor discharge temperature too high ....................................................................... 57
2.3.36 F3-20-21-22 – Compressor body temperature too high ............................................................................... 58
2.3.37 F4-01 – Wet operation caution...................................................................................................................... 59
2.3.38 F4-02-04-06 – Wet alarm for compressor M1C ............................................................................................ 60
2.3.39 F4-03-05-07 – Wet alarm for compressor M2C ............................................................................................ 62
2.3.40 F4-08-10-12 – Wet operation error for compressor M1C ............................................................................ 63
2.3.41 F4-09-11-13 – Wet operation error for compressor M2C ............................................................................ 65
2.3.42 F4-14 – Indoor unit wet operation alarm ...................................................................................................... 66
2.3.43 F6-01 – Refrigerant overcharge detection by high pressure sensor S1NPH................................................. 67
2.3.44 F6-02 – Refrigerant overcharge detection during test-run........................................................................... 69
2.3.45 F6-03 – Refrigerant overcharge detection by high subcool value ................................................................ 70
2.3.46 F9-01 – Branch selector box electronic expansion valve abnormality (high pressure/low pressure gas
pipe)................................................................................................................................................................ 72
2.3.47 F9-02 – Branch selector box electronic expansion valve abnormality (suction gas pipe)............................ 72
2.3.48 F9-03 – Branch selector box electronic expansion valve abnormality (subcooling)..................................... 73
2.3.49 H3-02-04-06 – Transmission error between main PCB A1P and inverter PCB A3P...................................... 74
2.3.50 H3-03-05-07 – Transmission error on inverter PCB A6P ............................................................................... 75
2.3.51 H7-01-05-09 – Defective fan inverter PCB A4P ............................................................................................. 75
2.3.52 H7-02-06-10 – Defective fan inverter PCB A7P ............................................................................................. 76

Table of contents
Service manual
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VRV IV+ Heat Recovery
ESIE18-15B – 2020.05
2.3.53 H7-21-23-25 – Defective fan inverter PCB A7P ............................................................................................. 77
2.3.54 H7-22-24-26 – Defective fan inverter PCB A4P ............................................................................................. 78
2.3.55 H9-01-02-03 – Ambient temperature thermistor R1T abnormality ............................................................. 78
2.3.56 HA-00 – Defrost fail alarm.............................................................................................................................. 79
2.3.57 J3-16-22-28 – Discharge thermistor R21T open circuit................................................................................. 80
2.3.58 J3-17-23-29 – Discharge thermistor R21T short circuit................................................................................. 80
2.3.59 J3-18-24-30 – Discharge thermistor R22T open circuit................................................................................. 81
2.3.60 J3-19-25-31 – Discharge thermistor R22T short circuit................................................................................. 82
2.3.61 J3-47-49-51 – Compressor body thermistor R15T open circuit.................................................................... 83
2.3.62 J3-48-50-52 – Compressor body thermistor R15T short circuit.................................................................... 83
2.3.63 J3-56-57-58 – High discharge temperature................................................................................................... 84
2.3.64 J3-59-60-61 – Discharge thermistor crosswired............................................................................................ 85
2.3.65 J5-01-03-05 – Compressor suction thermistor R12T malfunction................................................................ 86
2.3.66 J5-18-19-20 – Suction temperature thermistor R10T abnormality .............................................................. 87
2.3.67 J6-01-02-03 – De–icer thermistor R11T abnormality.................................................................................... 87
2.3.68 J6-08-09-10 – Upper heat exchanger gas pipe thermistor R8T malfunction................................................ 88
2.3.69 J6-11-12-13 – Lower heat exchanger gas pipe thermistor R9T malfunction................................................ 89
2.3.70 J7-01-02-03 – Main liquid pipe thermistor R3T malfunction ........................................................................ 90
2.3.71 J7-06-07-08 – Liquid thermistor R7T abnormality......................................................................................... 90
2.3.72 J8-01-02-03 – Upper heat exchanger liquid temperature thermistor R4T abnormality .............................. 91
2.3.73 J8-08-09-10 – Lower heat exchanger liquid temperature thermistor R5T abnormality .............................. 92
2.3.74 J8-11-12-13 – Autocharge thermistor R14T abnormality.............................................................................. 93
2.3.75 J9-01-02-03 – Gas thermistor R6T abnormality............................................................................................. 93
2.3.76 J9-08-09-10 – Gas thermistor R6T abnormality............................................................................................. 94
2.3.77 J9-11-12-13 – Receiver gas thermistor R13T abnormality ............................................................................ 95
2.3.78 JA-06-08-10 – High pressure sensor S1NPH abnormality ............................................................................. 96
2.3.79 JA-07-09-11 – High pressure sensor S1NPH malfunction.............................................................................. 96
2.3.80 JC-06-08-10 – Low pressure sensor S1NPL abnormality ............................................................................... 97
2.3.81 JC-07-09-11 – Low pressure sensor S1NPL malfunction ............................................................................... 98
2.3.82 L1-01-07-11 – Inverter PCB A3P abnormality................................................................................................ 99
2.3.83 L1-02-08-12 – Inverter PCB A3P current detection primary circuit .............................................................. 99
2.3.84 L1-03-09-13 – Inverter PCB A3P current detection secondary circuit .......................................................... 100
2.3.85 L1-04-10-14 – Power transistor error on inverter PCB A3P .......................................................................... 101
2.3.86 L1-05-15-16 – Inverter PCB A3P hardware fault ........................................................................................... 102
2.3.87 L1-17-22-42 – Inverter PCB A6P abnormality................................................................................................ 103
2.3.88 L1-18-23-43 – Inverter PCB A6P current detection primary circuit .............................................................. 104
2.3.89 L1-19-24-44 – Inverter PCB A6P current detection secondary circuit .......................................................... 105
2.3.90 L1-20-25-45 – Power transistor error on inverter PCB A6P .......................................................................... 106
2.3.91 L1-21-26-46 – Inverter PCB A6P hardware fault ........................................................................................... 106
2.3.92 L1-28-32-34 – Fan inverter PCB A4P Eeprom error....................................................................................... 107
2.3.93 L1-29-33-35 – Fan inverter PCB A7P Eeprom error....................................................................................... 108
2.3.94 L1-36-38-40 – Inverter PCB A3P Eeprom error ............................................................................................. 109
2.3.95 L1-37-39-41 – Inverter PCB A6P Eeprom error ............................................................................................. 109
2.3.96 L1-47-49-51 – Inverter PCB A3P 16 V DC abnormal ...................................................................................... 110
2.3.97 L1-48-50-52 – Inverter PCB A6P 16 V DC abnormal ...................................................................................... 111
2.3.98 L2-01-02-03 – Power supply abnormality during test run ............................................................................ 112
2.3.99 L2-04-05-06 – Power supply abnormality during normal operation ............................................................ 113
2.3.100 L4-01-02-03 – Inverter PCB A3P high fin temperature.................................................................................. 114
2.3.101 L4-06-18-20 – Fan inverter PCB A4P high fin temperature........................................................................... 115
2.3.102 L4-07-19-21 – Fan inverter PCB A7P high fin temperature........................................................................... 116
2.3.103 L4-09-10-11 – Inverter PCB A6P high fin temperature.................................................................................. 117
2.3.104 L5-03-05-07 – Output overcurrent detection on inverter PCB A3P.............................................................. 119
2.3.105 L5-14-15-16 – Output overcurrent detection on inverter PCB A6P.............................................................. 120
2.3.106 L8-03-06-07 – Overcurrent on inverter PCB A3P except start-up................................................................. 121
2.3.107 L8-11-12-13 – Overcurrent on inverter PCB A6P except start-up................................................................. 122
2.3.108 L9-01-05-06 – Stall prevention by inverter PCB A3P ..................................................................................... 123
2.3.109 L9-10-11-12 – Stall prevention by inverter PCB A6P ..................................................................................... 123
2.3.110 L9-13-14-15 – Inverter PCB A3P output phase abnormality ......................................................................... 124
2.3.111 L9-16-17-18 – Inverter PCB A6P output phase abnormality ......................................................................... 125
2.3.112 LC-01 – Transmission abnormality ................................................................................................................. 126
2.3.113 LC-14-15-16 – Transmission abnormality main PCB/inverter PCB A3P ........................................................ 127
2.3.114 LC-19-20-21 – Transmission abnormality main PCB/fan inverter PCB A4P .................................................. 127
2.3.115 LC-24-25-26 – Transmission abnormality main PCB/fan inverter PCB A7P .................................................. 128
2.3.116 LC-30-31-32 – Transmission abnormality main PCB/inverter PCB A6P ........................................................ 130
2.3.117 LC-33-34-35 – Transmission abnormality main PCB/sub PCB ....................................................................... 131
2.3.118 P1-01-02-03 – Open phase or unbalanced power supply detection by inverter PCB A3P........................... 131
2.3.119 P1-07-08-09 – Open phase or unbalanced power supply detection by inverter PCB A6P........................... 132
2.3.120 P2-00 – Refrigerant auto-charge interrupted................................................................................................ 133
2.3.121 P4-01-04-05 – Fin thermistor abnormality on inverter PCB A3P .................................................................. 133

Table of contents
Service manual
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REYQ8~20+REMQ5U7Y1B
VRV IV+ Heat Recovery
ESIE18-15B – 2020.05
2.3.122 P4-02-15-17 – Fin thermistor abnormality on fan inverter PCB A4P ............................................................ 134
2.3.123 P4-03-16-18 – Fin thermistor abnormality on fan inverter PCB A7P ............................................................ 135
2.3.124 P4-06-07-08 – Fin thermistor abnormality on inverter PCB A6P .................................................................. 136
2.3.125 P8-00 – Freeze-up during refrigerant auto-charge ....................................................................................... 137
2.3.126 P9-00 – Refrigerant auto-charge finished normally ...................................................................................... 138
2.3.127 PA-00 – No refrigerant in refrigerant cylinder during auto-charge .............................................................. 138
2.3.128 PE-00 – Refrigerant auto-charge in last stage ............................................................................................... 138
2.3.129 PF-00 – Long test run failed ........................................................................................................................... 139
2.3.130 PJ-04-05-06 – Capacity setting mismatch for inverter PCB A3P ................................................................... 139
2.3.131 PJ-09-15-16 – Capacity setting mismatch for fan inverter PCB A4P ............................................................. 140
2.3.132 PJ-10-17-18 – Capacity setting mismatch for fan inverter PCB A7P ............................................................. 141
2.3.133 PJ-12-13-14 – Capacity setting mismatch for inverter PCB A6P ................................................................... 142
2.3.134 U0 – Refrigerant shortage detection (Warning) ............................................................................................ 142
2.3.135 U0-05 – Refrigerant shortage detection........................................................................................................ 143
2.3.136 U0-06 – Refrigerant shortage detection........................................................................................................ 144
2.3.137 U0-08-09-10 – Refrigerant shortage detection by high pressure sensor ..................................................... 145
2.3.138 U1-01-05-07 – Reverse phase detection ....................................................................................................... 146
2.3.139 U1-04-06-08 – Reverse phase detection ....................................................................................................... 147
2.3.140 U1-16-17-18 – Open phase detection on Power supply ............................................................................... 147
2.3.141 U1-19-20-21 – Hz error detection on Power Supply ..................................................................................... 148
2.3.142 U2-01-08-11 – Inverter circuit power supply abnormality - inverter PCB A3P abnormal voltage ............... 149
2.3.143 U2-02-09-12 – Inverter circuit power supply abnormality - inverter PCB A3P phase loss........................... 150
2.3.144 U2-03-10-13 – Inverter circuit power supply abnormality - inverter PCB A3P DC circuit not charging....... 151
2.3.145 U2-22-25-28 – Inverter circuit power supply abnormality - inverter PCB A6P abnormal voltage ............... 152
2.3.146 U2-23-26-29 – Inverter circuit power supply abnormality - inverter PCB A6P phase loss........................... 153
2.3.147 U2-24-27-30 – Inverter circuit power supply abnormality - inverter PCB A6P DC circuit not charging....... 154
2.3.148 U3-02 – Test run interrupted manually ......................................................................................................... 155
2.3.149 U3-03 – Test run not performed yet.............................................................................................................. 156
2.3.150 U3-04 – Test run ended abnormally .............................................................................................................. 157
2.3.151 U3-05 – Test run aborted on initial transmission .......................................................................................... 157
2.3.152 U3-06 – Test run aborted on normal transmission ....................................................................................... 158
2.3.153 U3-07 – Transmission abnormality on test run ............................................................................................. 159
2.3.154 U3-08 – Transmission abnormality on test run ............................................................................................. 159
2.3.155 U4-01 – Transmission error between indoor units and outdoor unit........................................................... 160
2.3.156 U4-03 – Transmission error between indoor units and system.................................................................... 161
2.3.157 U4-15 – Unable to start test run .................................................................................................................... 162
2.3.158 U7-01 – Transmission abnormality between systems - DTA104A61,62 error.............................................. 162
2.3.159 U7-02 – Transmission abnormality between systems - DTA104A61,62 error.............................................. 163
2.3.160 U7-03 – Transmission abnormality between main outdoor unit and sub 1 outdoor unit ........................... 164
2.3.161 U7-04 – Transmission abnormality between main outdoor unit and sub 2 outdoor unit ........................... 165
2.3.162 U7-05 – Multi system abnormality ................................................................................................................ 165
2.3.163 U7-06 – Multi system address abnormality................................................................................................... 166
2.3.164 U7-07 – More than 3 outdoor units on Q1-Q2 transmission ........................................................................ 166
2.3.165 U7-11 – Excess indoor units detected on test run ........................................................................................ 167
2.3.166 U7-24 – Duplication of address setting on multiple DTA104A61,62 installation ......................................... 168
2.3.167 U9-01 – Other indoor unit has error.............................................................................................................. 168
2.3.168 UA-00 – Combination abnormality ................................................................................................................ 169
2.3.169 UA-03 – Combination abnormality - Mix of R22, R407C and R410A type units detected............................ 169
2.3.170 UA-16 – Combination abnormality - More than 64 indoor units detected on same system ....................... 170
2.3.171 UA-17 – Combination abnormality - Local setting abnormality.................................................................... 170
2.3.172 UA-18 – Combination abnormality - Outdoor unit not compatible with indoor units (refrigerant type).... 171
2.3.173 UA-19 – Combination abnormality - Local set alarm..................................................................................... 171
2.3.174 UA-20 – Combination abnormality - Non-compatible outdoor unit in multi-combination.......................... 172
2.3.175 UA-21 – Combination abnormality - BPMK units detected........................................................................... 172
2.3.176 UA-22 – Combination abnormality - Single Installation ................................................................................ 172
2.3.177 UA-23 – Branch selector box Abnormality - Connected Indoor Unit Index too High ................................... 173
2.3.178 UA-25 – Branch selector box Abnormality - Transmission Wiring Abnormality between BS Unit and
Outdoor Unit................................................................................................................................................... 173
2.3.179 UA-26 – Branch selector box Abnormality - Transmission Wiring Abnormality on branch selector box..... 174
2.3.180 UA-27 – Branch selector box Abnormality - no branch selector box detected ............................................ 175
2.3.181 UA-28 – Branch selector box Abnormality - non-compatible branch selector box detected ...................... 176
2.3.182 UA-29 – Branch selector box Abnormality - Connected Indoor Unit Index too Low.................................... 176
2.3.183 UA-30 – Combination Abnormality - Heat Pump and Heat Recovery Outdoor Units Detected in Same
Combination ................................................................................................................................................... 177
2.3.184 UA-31 – Combination abnormality - REMQ-U Unit Detected Without a Multi Combination ...................... 177
2.3.185 UA-35 – Combination abnormality - REMQ-U Unit Detected in Wrong Combination ................................. 178
2.3.186 UA-38 – Combination abnormality - Altherma hydro unit detected ............................................................ 178
2.3.187 UA-39 – Combination abnormality - Incorrect combination......................................................................... 179
2.3.188 UA-43 – Combination abnormality - Incorrect combination......................................................................... 179
2.3.189 UA-49 – Combination abnormality - Wrong unit combination ..................................................................... 179

Table of contents
Service manual
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REYQ8~20+REMQ5U7Y1B
VRV IV+ Heat Recovery
ESIE18-15B – 2020.05
2.3.190 UA-50 – Combination abnormality - High Temperature Hydrobox Detected Connected to a BS Unit ....... 180
2.3.191 UA-51 – Combination abnormality - Only Hydrobox Units Detected ........................................................... 180
2.3.192 UA-53 – Combination abnormality - Branch Selector box Dip Switch Abnormality ..................................... 180
2.3.193 UF-01 – Wiring and piping mismatch - Auto address inconsistency on F1-F2 transmission........................ 181
2.3.194 UF-05 – Wiring and piping mismatch - Stop valves closed or incorrect ....................................................... 182
2.3.195 UF-11 – Wiring and piping mismatch - Excess connection ratio ................................................................... 183
2.3.196 UH-01 – Auto-address failure......................................................................................................................... 183
2.3.197 UH-02 – Auto-address failure......................................................................................................................... 184
2.3.198 E-1 – Refrigerant leak check is not possible................................................................................................... 185
2.3.199 E-2 – Refrigerant leak check cannot be performed - indoor air temperature is out of range ..................... 186
2.3.200 E-3 – Refrigerant leak check cannot be performed - outdoor air temperature is out of range................... 186
2.3.201 E-4 – Refrigerant leak check is interrupted - too low pressure is detected.................................................. 187
2.3.202 E-5 – Refrigerant leak check cannot be performed - a unit which is not compatible with leak detection
function is installed ........................................................................................................................................ 187
2.3.203 NG – Refrigerant leak check function detects refrigerant leak ..................................................................... 188
2.3.204 OK – Refrigerant leak check function detects no refrigerant leak ................................................................ 188
2.3.205 Indoor unit related error codes...................................................................................................................... 188
2.3.206 Overview of error codes................................................................................................................................. 191
2.4 Symptom based troubleshooting ................................................................................................................................... 198
2.4.1 Normal operating conditions ......................................................................................................................... 198
2.4.2 Symptom: The system does not operate....................................................................................................... 198
2.4.3 Symptom: Cool/Heat cannot be changed over ............................................................................................. 199
2.4.4 Symptom: Fan operation is possible, but cooling and heating do not work ................................................ 199
2.4.5 Symptom: The fan speed does not correspond to the setting...................................................................... 199
2.4.6 Symptom: The fan direction does not correspond to the setting................................................................. 199
2.4.7 Symptom: White mist comes out of a unit (Indoor unit) .............................................................................. 199
2.4.8 Symptom: White mist comes out of a unit (Indoor unit, heat exchanger unit)............................................ 199
2.4.9 Symptom: The user interface reads "U4" or "U5" and stops, but then restarts after a few minutes.......... 200
2.4.10 Symptom: Noise of air conditioners (Indoor unit)......................................................................................... 200
2.4.11 Symptom: Noise of air conditioners (Indoor unit, outdoor unit) .................................................................. 200
2.4.12 Symptom: Noise of air conditioners (Outdoor unit)...................................................................................... 200
2.4.13 Symptom: Dust comes out of the unit........................................................................................................... 200
2.4.14 Symptom: The units can give off odours ....................................................................................................... 200
2.4.15 Symptom: The outdoor unit fan does not spin.............................................................................................. 200
2.4.16 Symptom: The display shows "88"................................................................................................................. 201
2.4.17 Symptom: The compressor in the outdoor unit does not stop after a short heating operation ................. 201
2.4.18 Symptom: The inside of an outdoor unit is warm even when the unit has stopped.................................... 201
2.4.19 Symptom: Hot air can be felt when the indoor unit is stopped.................................................................... 201
2.4.20 Symptom: Unit operation problems .............................................................................................................. 202
2.4.21 Other symptoms............................................................................................................................................. 204
3 Components 206
3.1 4-way valve...................................................................................................................................................................... 206
3.1.1 Checking procedures...................................................................................................................................... 206
3.1.2 Repair procedures .......................................................................................................................................... 211
3.2 Branch selector box PCB................................................................................................................................................. 214
3.2.1 Checking procedures...................................................................................................................................... 214
3.2.2 Repair procedures .......................................................................................................................................... 217
3.3 Compressor ..................................................................................................................................................................... 221
3.3.1 Checking procedures...................................................................................................................................... 221
3.3.2 Repair procedures .......................................................................................................................................... 227
3.4 Crankcase heater ............................................................................................................................................................ 234
3.4.1 Checking procedures...................................................................................................................................... 234
3.4.2 Repair procedures .......................................................................................................................................... 236
3.5 Current sensor ................................................................................................................................................................ 237
3.5.1 Checking procedures...................................................................................................................................... 237
3.5.2 Repair procedures .......................................................................................................................................... 238
3.6 E-bridge ........................................................................................................................................................................... 240
3.6.1 Checking procedures...................................................................................................................................... 240
3.6.2 Repair procedures .......................................................................................................................................... 242
3.7 Expansion valve............................................................................................................................................................... 244
3.7.1 Outdoor unit expansion valve ........................................................................................................................ 244
3.7.2 Branch selector box expansion valve............................................................................................................. 252
3.8 Fan inverter PCB.............................................................................................................................................................. 259
3.8.1 Single fan outdoor unit................................................................................................................................... 259
3.8.2 Double fan outdoor unit................................................................................................................................. 265
3.9 High pressure switch....................................................................................................................................................... 270
3.9.1 Checking procedures...................................................................................................................................... 270
3.9.2 Repair procedures .......................................................................................................................................... 272
3.10 Inverter PCB .................................................................................................................................................................... 274

Table of contents
Service manual
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REYQ8~20+REMQ5U7Y1B
VRV IV+ Heat Recovery
ESIE18-15B – 2020.05
3.10.1 Checking procedures...................................................................................................................................... 274
3.10.2 Repair procedures .......................................................................................................................................... 282
3.11 Main PCB ......................................................................................................................................................................... 290
3.11.1 Checking procedures...................................................................................................................................... 290
3.11.2 Repair procedures .......................................................................................................................................... 293
3.12 Noise filter PCB ............................................................................................................................................................... 298
3.12.1 Checking procedures...................................................................................................................................... 298
3.12.2 Repair procedures .......................................................................................................................................... 301
3.13 Oil return valve................................................................................................................................................................ 302
3.13.1 Checking procedures...................................................................................................................................... 302
3.13.2 Repair procedures .......................................................................................................................................... 304
3.14 Outdoor unit fan motor .................................................................................................................................................. 307
3.14.1 Single fan outdoor unit................................................................................................................................... 307
3.14.2 Double fan outdoor unit................................................................................................................................. 311
3.15 Plate work ....................................................................................................................................................................... 315
3.15.1 To access the switch box on single fan units ................................................................................................. 315
3.15.2 To access the switch box on double fan units ............................................................................................... 317
3.15.3 To remove the plate work on single fan units ............................................................................................... 318
3.15.4 To remove the plate work on double fan units ............................................................................................. 322
3.15.5 To remove the plate work on the branch selector box ................................................................................. 326
3.16 Reactor ............................................................................................................................................................................ 328
3.16.1 Checking procedures...................................................................................................................................... 328
3.16.2 Repair procedures .......................................................................................................................................... 328
3.17 Refrigerant high pressure sensor ................................................................................................................................... 330
3.17.1 Checking procedures...................................................................................................................................... 330
3.17.2 Repair procedures .......................................................................................................................................... 332
3.18 Refrigerant low pressure sensor..................................................................................................................................... 333
3.18.1 Checking procedures...................................................................................................................................... 333
3.18.2 Repair procedures .......................................................................................................................................... 336
3.19 Solenoid valve ................................................................................................................................................................. 337
3.19.1 Checking procedures...................................................................................................................................... 337
3.19.2 Repair procedures .......................................................................................................................................... 339
3.20 Sub PCB ........................................................................................................................................................................... 342
3.20.1 Checking procedures...................................................................................................................................... 342
3.20.2 Repair procedures .......................................................................................................................................... 345
3.21 Thermistors ..................................................................................................................................................................... 348
3.21.1 Refrigerant side thermistors .......................................................................................................................... 348
3.21.2 Other thermistors........................................................................................................................................... 355
4 Third party components 356
4.1 Electrical circuit............................................................................................................................................................... 356
4.1.1 Checking procedures...................................................................................................................................... 356
4.1.2 Repair procedures .......................................................................................................................................... 361
4.2 Refrigerant circuit ........................................................................................................................................................... 363
4.2.1 Checking procedures...................................................................................................................................... 363
4.2.2 Repair procedures .......................................................................................................................................... 368
4.3 External factors ............................................................................................................................................................... 372
4.3.1 Checking procedures...................................................................................................................................... 372
5 Maintenance 374
5.1 Maintenance shedule ..................................................................................................................................................... 374
5.2 Maintenance procedures for outdoor units .................................................................................................................. 375
5.2.1 To check the general status of the unit ......................................................................................................... 375
5.2.2 To clean the cover plates ............................................................................................................................... 376
5.2.3 To clean the outdoor unit heat exchanger .................................................................................................... 376
5.3 Maintenance procedures for indoor units ..................................................................................................................... 377
5.3.1 To check the general status of the unit ......................................................................................................... 377
5.3.2 To clean the cover plates ............................................................................................................................... 378
5.3.3 To clean the indoor unit heat exchanger....................................................................................................... 378
5.4 Maintenance procedures for Branch Selector Boxes .................................................................................................... 379
5.4.1 To clean the cover plates ............................................................................................................................... 379
5.4.2 To check the general status of the Branch Selector Box ............................................................................... 379
Direct expansion: Maintenance – VRV ........................................................................................................................... 381
6 Technical data 384
6.1 Detailed information setting mode ................................................................................................................................ 384
6.1.1 Detailed information setting mode: Outdoor unit ........................................................................................ 384
6.1.2 Detailed information setting mode: Remote controller................................................................................ 384
6.2 Wiring diagram................................................................................................................................................................ 385
6.2.1 Wiring diagram: Outdoor unit........................................................................................................................ 385

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6.2.2 Wiring diagram: Branch selector box............................................................................................................. 393
6.3 Piping diagram ................................................................................................................................................................ 401
6.3.1 Piping diagram: Outdoor unit......................................................................................................................... 401
6.3.2 Refrigerant flow diagram: Outdoor unit ........................................................................................................ 407
6.3.3 Piping diagram: Branch selector unit............................................................................................................. 432
6.4 Component overview...................................................................................................................................................... 441
6.4.1 Component overview: REMQ5U + REYQ8~12U units ................................................................................... 441
6.4.2 Component overview: REYQ14~20U units .................................................................................................... 443
6.5 Switchbox overview ........................................................................................................................................................ 445
6.5.1 Single fan units ............................................................................................................................................... 445
6.5.2 Double fan units ............................................................................................................................................. 446
6.5.3 Branch selector box........................................................................................................................................ 447
6.6 Safety devices.................................................................................................................................................................. 449
6.7 Field information report ................................................................................................................................................. 451
6.8 Service tools .................................................................................................................................................................... 454
6.9 Field settings ................................................................................................................................................................... 455
6.9.1 To access mode 1 or 2.................................................................................................................................... 455
6.9.2 To use mode 1 ................................................................................................................................................ 455
6.9.3 To use mode 2 ................................................................................................................................................ 456
6.9.4 Mode 1: Field settings .................................................................................................................................... 458
6.9.5 Mode 2: Field settings .................................................................................................................................... 461
6.9.6 Overview of field settings for indoor units .................................................................................................... 466
6.9.7 Field settings as per type of indoor unit ........................................................................................................ 471

1 | General operation
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1 General operation
The VRV IV+ HR (Heat Recovery) system consists of 3 types of units:
▪Outdoor units
▪Branch selector (BS) units
▪Indoor units
Outdoor units
The VRV IV+ HR (Heat Recovery) comes in two different types of outdoor unit
casing:
Small casing (5/8/10/12 HP) Large casing (14/16/18/20 HP)
There are 2 types of outdoor units:
REYQ-U units can be used as stand-alone units and in multi combinations.
REMQ5U units can ONLY be used in multi combinations and not as stand-alone
units.
There are only 2 combination possibilities for REMQ5U units:
Multi combination Outdoor unit 1 Outdoor unit 2
REYQ10U REMQ5U REMQ5U
REYQ13U REYQ8U REMQ5U
U-series and T-series cannot be used together in multi combination.
INFORMATION
U-series units cannot share the same refrigerant circuit with T-series units. However,
electrically, U-series units and T-series units can be present on the same F1/F2 OUT
wiring for central controller connection.
Up to 3 modules of VRV IV+ HR outdoor units can be connected using refnet
BHFQ23P.
Field piping must be thermally insulated copper piping, connected to a
combination of single circuit branch selector unit(s) or/and multi circuit branch
selector unit(s).
Branch Selector units (BS)
A single branch selector unit has only 1 refrigerant circuit.
Multi branch selector units have 4,6,8,10,12 or 16 refrigerant circuits.
To split the refrigerant circuit between outdoor units and different branch selector
units, KHRQ22M refnet branches are used.
After the branch selector unit, one or more indoor units can be connected. To split
the refrigerant circuit for the different indoor units from the same branch selector
unit, Daikin optional accessory refnets (KHRQ22M) are used.

1 | General operation
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The HT (high temperature) Hydrobox is connected without branch selector unit:
only use the HP (high pressure) gas line and the liquid line.
Single Branch Selector (BS) Multi Branch Selector (BS)
BS1Q10A
BS1Q16A
BS1Q25A
BS4Q14A
BS6Q14A
BS8Q14A
BS10Q14A
BS12Q14A
BS16Q14A
There are 2 types of branch selector (BS) units, each of them available in different
capacities:
▪Single circuit branch selector units:
-BS1Q10A: indoor index below 100 (100 NOT included).
-BS1Q16A: indoor index from 100 and below 160 (160 NOT included).
-BS1Q25A: indoor index from 160 to 250 (250 included).
▪Multi circuit branch selector units:
-BS4Q14A: maximum 4 circuits.
-BS6Q14A: maximum 6 circuits.
-BS8Q14A: maximum 8 circuits.
-BS10Q14A: maximum 10 circuits.
-BS12Q14A: maximum 12 circuits.
-BS16Q14A: maximum 16 circuits.
Each single circuit can have:
-Maximum 5 indoor units connected.
-Maximum index 140 (total index for all connected indoor units).

1 | General operation
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Indoor Units
The below illustration does not reflect allowed combinations or compatibility. The intention is to give an overview
on piping installation for different types of units.
a
b
a
ccc
k
k
d
n
h
g
i
kkk
k
kk
h
g
j
m
m
m
m
m
m
m
me
l
f f f
aVRV IV+ HR outdoor unit
bRefnet BHFQ23P for outdoor multi connection
cRefnet KHRQ23M
dMulti branch selector unit
eRefnet KHRQ22M
fVRV DX indoor unit
gLow temperature Hydrobox (HXY-A)
hSingle branch selector unit
iEKEXV
jAir handling unit
k3 pipes (high pressure gas, low pressure gas, liquid)
lHigh temperature Hydrobox (HXHD-A)
m2 pipes (gas, liquid)
n2 pipes (high pressure gas, liquid)

1 | General operation
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VRV systems have combination limits for different types of indoor units and also limits for piping length and
connection ratio for each indoor unit combination pattern. Refer to the Engineering Databook.
The list below is only for reference of compatible units. Always refer to Engineering Databook for compatibility.
Round flow
cassette FXFQ
Ceiling suspended
FXHQ
Fully flat cassette
FXZQ
4 Way ceiling
suspended – FXUQ
2 Way cassette
FXCQ
Concealed floor
standing - FXNQ
Corner cassette
FXKQ
Floor standing
FXLQ
Concealed ceiling
FXDQ
AHU kit EKEXV +
EKEQM - EKEQF
Concealed ceiling
with medium ESP -
FXSQ
Low temperature
Hydrobox - HXY
Concealed ceiling
with high ESP -
FXMQ
High temperature
Hydrobox - HXHD
Wall mounted
FXAQ
Air curtain CYVS,
CYVM, CYVL

2 | Troubleshooting
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2 Troubleshooting
2.1 To access push buttons and 7-segment display
1Remove the service plate, see "3.15Plate work"[4315].
Result: The push buttons and 7-segment display are located on A1P behind the
service plate.
b
a
aPush buttons
b7-segment display
2.2 To retrieve error codes and check error history
2.2.1 Via the indoor unit remote controller BRC1H
INFORMATION
Images are in English and for reference ONLY. For more details on the Madoka
Assistant please refer to the BRC1H training course material which is available on the
Daikin Business Portal.
To retrieve the error code
To indicate a system error, the controller displays on the messages zone of the
home screen.
b
a
c
aMessages zone
bMiddle button
cError screen
1Press the middle button to enter the main menu from the home screen.
Result: An error screen is displayed.
2Press the middle button to return to the home screen.

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Active error codes are also accessible through the Madoka Assistant for BRC1H.
The active error is shown on the home screen.
e gd f
dActive error
eHome screen
fError(s) details
gNotifications screen
3Tap the active error.
Result: The detail(s) of the error(s) are shown on the Notifications screen.
To check the error history
To check the error history with the Madoka Assistant for BRC1H:
# Action Image for reference Result
1 Tap the settings icon. The Unit settings
screen is displayed.

2 | Troubleshooting
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# Action Image for reference Result
2 Tap Errors and
warnings.
The Errors and
warnings screen is
displayed.
3 Tap Error history.
The Error history screen
is displayed.
2.2.2 Via the outdoor unit
Error codes and/or retry descriptions are accessible on “Mode 1: Monitor Mode”.
The table below shows which setting shows the error codes that led to an outdoor
unit forced stop and/or retry.
▪When an error is generated, the unit performs a forced off until the error is
retrieved.
▪On retry, the system attempts to stay in operation. Depending on the type of
root cause, after a certain amount of retry attempts, the unit generates an error.
Retry cause is also visible as an item on the service monitoring tool.
Mode Setting Description
Mode 1: Monitor
mode
17 Error code last forced off
18 Error code 2nd last forced off
19 Error code 3rd last forced off
23 Error code last retry
24 Error code 2nd last retry
25 Error code 3rd last retry
Please follow the procedure described below to access the regarding error code for
outdoor unit forced stop and/or retry description:

2 | Troubleshooting
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Action Result Display
Make sure the 7-segment
display indication is as
during normal operation.
To enter “Mode 1”, push
the (BS1) button one time
Mode 1 is accessed.
Push the (BS2) button as
many times as the setting
you want to go to.
The setting is accessed
(e.g. 17, Error code last
forced off)
Press the RETURN (BS3)
Button.
Malfunction/Retry item
will appear on display.
Press the SET (BS2)
Button.
Detailed Malfunction/
Retry sub-code will
appear on display.
Press SET (BS2) once
again to return to main
Malfunction/Retry
display.
Main Malfunction/Retry
item will appear on
display.
Press the RETURN (BS3)
Button to return to Home
Screen for “Monitoring
Mode”.
Home Screen for
“Monitoring Mode” will
appear on display.
Press the MODE (BS1)
Button to return to
“Normal Mode”.
Back in normal mode.
2.2.3 Via the wired remote control BRC1E
INFORMATION
Images are in English and for reference ONLY. For more details on the BRC1E please
refer to the user manual.
To retrieve the error code
In case of an error or warning, the operation lamp on the ON/OFF button blinks
and an error message or warning is displayed at the bottom of the screen.
a
b
c
aOperation lamp on the ON/OFF button
bError message

2 | Troubleshooting
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cWarning
# Action Result
1 Press. The error code appears on the
screen. The content of the error/
warning is displayed.
To Check the error history
# Action Result
1 Go to the basic screen.
Cool
Set to
28°C
2 Press at least 4seconds while the
backlight of the screen is lit.
The Service Settings screen is
displayed.
3 Select Error History
4 Press. The Error History screen is
displayed.
5 Select RC Error History or Indoor
Unit Error History.
6 Press. ▪The RC Error History screen
shows error history for all units
in case of group control
▪The Indoor Unit Error History
screen shows error history of the
selected indoor unit

2 | Troubleshooting
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2.2.4 Via the wireless controller BRC4/7
To retrieve the error code
e
c
d
b
a
g
f
aINSPECTION/TEST button
bUnit No.
cUP button
dDOWN button
eMODE button
fLeft digit
gRight digit
1Press and hold INSPECTION/TEST button for 5seconds.
Result: The "unit indication" is displayed on screen and Unit No. is displayed
as "0", blinking.
2Set the Unit No. via UP/DOWN buttons until a buzzer sound* is generated
from the indoor unit.
Result: *Possible buzzer sounds:
-3 short beeps; conduct all items of the following procedure.
-1 short beep; conduct steps 3 and 4. Continue the operation in step 4 until the
buzzer sounds continuously.
-Continuous buzzer; indicates the error code is confirmed.
3Press the MODE button.
Result: The left digit of the error code on display will blink.
4Press UP/DOWN buttons to change the left digit of the error code.
Result: The left digit changes as indicated below.
UP button
DOWN button
5Continue to change until the matching buzzer sound** is generated.
Result: **Possible buzzer sounds:
-Continuous buzzer; both digits match with the error code.
-2 short beeps; left digit matches with the error code.
-1 short beep; right digit matches with the error code.
6Press the MODE button.
Result: The right digit of the error code on display will blink.

2 | Troubleshooting
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7Press UP/DOWN buttons to change the right digit of the error code.
Result: The right digit changes as indicated below.
UP button
DOWN button
8Continue to change until the matching buzzer sound*** is generated.
Result: ***Possible buzzer sounds:
-Continuous buzzer; both digits match with the error code.
-2 short beeps; left digit matches with the error code.
-1 short beep; right digit matches with the error code.
To check the error history
INFORMATION
It is not possible to acces the error history with the wireless controller BRC4/7.
2.2.5 Via the wired remote control BRC1D
To retrieve the error code
a
d
e
c
b
f
aRemote controller’s operation LED
bError code
cInspection display
dTEST button
eUnit No.
fTemperature set button
If operation stops due to a malfunction, the remote controller’s operation LED will
blink and an error code will be displayed.
The error code will stay available at inspection mode even after forced off
operation or after the error is reset.
The inspection display and error code blink while an error is active.
To access the error code while in normal operation; follow the procedure below:
1Press TEST button once.
Result: Error code for corresponding Unit No will be displayed.
2Press TEST button.
Result: Indoor unit model code will be displayed.