12 Troubleshooting
Installer reference guide
82
RRLQ004~008CA + RHBH/X04+08CB
ROTEX HPSU low temperature Bi‑bloc
4P384979-1C – 2017.04
Error code
Detailed error
code
Description
A1
01
EEPROM reading error.
AA
01
Backup heater overheated.
Power reset required.
Please contact your dealer.
AC
00
Booster heater overheated.
Please contact your dealer.
AH
00
Tank disinfection function not
completed correctly.
AJ
03
Too long DHW heat-up time
required.
C0
00
Flow sensor/switch malfunction.
Please contact your dealer.
C4
00
Heat exchanger temperature
sensor problem.
Please contact your dealer.
CJ
02
Room temperature sensor
problem.
Please contact your dealer.
EC
00
Abnormal increase tank
temperature.
H1
00
External temperature
sensor problem.
Please contact your dealer.
HC
00
Tank temperature sensor
problem.
Please contact your dealer.
U3
00
Under floor heating screed
dryout function not completed
correctly.
U4
00
Indoor/outdoor unit
communication problem.
U5
00
User interface
communication problem.
U8
01
Connection with adapter lost
Please contact your dealer.
UA
00
Indoor unit, outdoor unit
matching problem.
Power reset required.
Error code
Detailed error
code
Description
UA
17
Tank type problem
INFORMATION
In case of error code AH and no interruption of the
disinfection function occurred due to domestic hot water
tapping, following actions are recommended:
▪ When the Domestic hot water > Type > Reheat or
Reheat + sched. is selected, it is recommended to
program the start-up of the disinfection function at least
4 hours later than the last expected large hot water
tapping. This start-up can be set by installer settings
(disinfection function).
▪ When the Domestic hot water > Type > Scheduled only
is selected, it is recommended to program a Storage
eco 3 hours before the scheduled start-up of the
disinfection function to preheat the tank.
NOTICE
When the minimum water flow is lower than described in
the table below, the unit will temporarily stop operation and
the user interface will display error 7H‑01. After some time,
this error will reset automatically and the unit will resume
operation.
Minimum required flow during heat pump operation
04 models
Heating
6 l/min
Cooling
6 l/min
08 models
Heating
6 l/min
Cooling
10 l/min
11 models
Heating
10 l/min
Cooling
15 l/min
16 models
Heating
10 l/min
Cooling
15 l/min
Minimum required flow during defrost operation
04+08 models
12 l/min
11+16 models
15 l/min
Minimum required flow during backup heater operation
All models
12 l/min
If the 7H‑01 error persists, the unit will stop operation and the user
interface will display an error code that needs to be reset manually.
Depending on the problem, this error code is different:
Error code
Detailed error
code
Description
7H
04
The water flow problems mainly
occurred during domestic hot
water operation. Check the
domestic hot water circuit.
7H
05
The water flow problems mainly
occurred during space heating
operation. Check the space
heating circuit.
