12 Troubleshooting
Installer reference guide
80
RRLQ004~008CA + RHBH/X04+08CB
ROTEX HPSU low temperature Bi‑bloc
4P384979-1 – 2015.01
Error code
Detailed error
code
Description
J6
00
OU: Malfunction of heat
exchanger thermistor.
Please contact your dealer.
L3
00
OU: Electrical box temperature
rise problem.
Please contact your dealer.
L4
00
OU: Malfunction of inverter
radiating fin temperature rise.
Please contact your dealer.
L5
00
OU: Inverter instantaneous
overcurrent (DC).
Please contact your dealer.
P4
00
OU: Malfunction of radiating
fin temperature sensor.
Please contact your dealer.
U0
00
OU: Shortage of refrigerant.
Please contact your dealer.
U2
00
OU: Defect of power supply
voltage.
Please contact your dealer.
U7
00
OU: Transmission malfunction
between main CPU- INV CPU.
Please contact your dealer.
UA
00
OU: Indoor/outdoor combination
problem.
Power reset required.
Error codes of the indoor unit
Error code
Detailed error
code
Description
A1
00
Zero cross detection problem.
Power reset required.
Please contact your dealer.
AA
01
Backup heater overheated.
Power reset required.
Please contact your dealer.
UA
00
Indoor unit, outdoor unit
matching problem.
Power reset required.
7H
01
Water flow problem.
89
01
Heat exchanger frozen.
8H
00
Abnormal increase outlet
water temperature.
Error code
Detailed error
code
Description
8F
00
Abnormal increase outlet
water temperature (DHW).
C0
00
Flow sensor/switch malfunction.
Please contact your dealer.
U3
00
Under floor heating screed
dryout function not completed
correctly.
81
00
Leaving water temperature
sensor problem.
Please contact your dealer.
C4
00
Heat exchanger temperature
sensor problem.
Please contact your dealer.
80
00
Returning water temperature
sensor problem.
Please contact your dealer.
U5
00
User interface
communication problem.
U4
00
Indoor/outdoor unit
communication problem.
AC
00
Booster heater overheated.
Please contact your dealer.
EC
00
Abnormal increase tank
temperature.
HC
00
Tank temperature sensor
problem.
Please contact your dealer.
CJ
02
Room temperature sensor
problem.
Please contact your dealer.
H1
00
External temperature
sensor problem.
Please contact your dealer.
89
02
Heat exchanger frozen.
A1
01
EEPROM reading error.
AH
00
Tank disinfection function not
completed correctly.