10 Troubleshooting
Installation manual
47
RWEQ96~432TAYCU
VRV W T-Series water-cooled system air conditioner
4P540122-1B – 2018.11
Malfunction code
Contents Solution
Main
code
Sub code
Master/sub 1/sub 2
U2
01/08/11 Voltage power shortage. ▪ Checkifpowersupplyiswithintherange.
▪ Correctphaseorder.
02/09/12 Reversed or open power supply phase. ▪ Checkifpowersupplyiswithintherange.
▪ Correctphaseorder.
U3
01 System test run not yet executed (system operation
not possible).
Execute system test run.
05 Test run aborted. Re-execute the test run.
06
07 Test run aborted due to communication issues. Check the communication wires and re-execute the
test run.
08
U4
01 Faulty wiring to Q1/Q2 or indoor- outside. Connect transmission wiring of indoor units to “TO
IN/D UNIT (F1, F2)” and transmission wiring of other
outside units to “TO OUT/D UNIT (F1, F2)”.
03 Malfunction of connected indoor unit. Check the malfunction code of indoor unit and
resolve it.
U7
01 Faulty wiring to Q1/Q2 or indoor- outside. Connect transmission wiring of indoor units to “TO
IN/D UNIT (F1, F2)” and transmission wiring of other
outside units to “TO OUT/D UNIT (F1, F2)”.
02
03
U9
01 ▪ Systemmismatch.Wrongtypeofindoorunits
combined (R407C, Mini-split, etc).
▪ Indoorunitmalfunction.
Check if other indoor units have malfunction and
confirm indoor unit mix is allowed.
UA
18 Connection malfunction over indoor units or type
mismatch (R407C, Mini-split, etc).
Check if other indoor units have malfunction and
confirm indoor unit mix is allowed.
20 Wrong combination of outside units (different series
(e.g. RWEQ and RWEYQ), or different type (e.g. P
type and T type)).
Correct the units combination.
27 Assembly defect of indoor and outside units (e.g.
different models, number of units or part numbers, or
different series are mixed).
▪ Checkandmodifythenumberofindoorunitsthat
are connected.
▪ Checkthetypeofrefrigerantforindoorandoutside
units, and replace them with adaptable indoor/
outside units in the case of inconsistency.
UH
01 Auto address malfunction (inconsistency) Check if transmission wired unit amount matches
with powered unit amount (by monitor mode) or wait
till initialization is finished.
UF
01 ▪ Autoaddressmalfunction(inconsistency)
▪ Stop valves closed.
▪ Check if transmission wired unit amount matches
with powered unit amount (by monitor mode) or
wait till initialization is finished.
▪ Open stop valves.
Refer to service manual for full list of error codes.