12 Troubleshooting
Possible causes
Too much heat pump capacity is
used for heating domestic hot
water (applies only to
installations with a domestic hot
water tank)
12.3.7
Symptom: The pressure at the tapping
point is temporarily unusually high
Possible causes
Failing or blocked pressure relief
valve.
12.3.8
Symptom: Decoration panels are pushed
away due to a swollen tank
Possible causes
Failing or blocked pressure relief
valve.
12.3.9
Symptom: Tank disinfection function is
NOT completed correctly (AH-error)
Possible causes
The disinfection function was
interrupted by domestic hot water
tapping
Large domestic hot water tapping
happened recently before the
programmed start-up of the
disinfection function
Installer reference guide
80
Corrective action
Check and make sure that the
"space heating priority" settings
have been configured
appropriately:
▪ Make sure that the "space
heating priority status" has
been enabled. Go to [A.8] >
Installer settings > Overview
settings [5‑02]
▪ Increase the "space heating
priority
temperature"
to
activate
backup
heater
operation at a higher outdoor
temperature. Go to [A.8] >
Installer settings > Overview
settings [5‑03]
Corrective action
▪ Flush and clean the complete
tank
including
the
piping
between pressure relief valve
and the cold water inlet.
▪ Replace the pressure relief
valve.
Corrective action
Contact your local dealer.
Corrective action
Program the start-up of the
disinfection function when the
coming 4 hours NO domestic hot
water tapping is expected.
When the Domestic hot water >
Type > Reheat or Reheat +
sched. is selected, it is
recommended to program the
start-up 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.
Possible causes
The disinfection operation was
stopped manually: with the user
interface displaying the DHW
home page and its user
permission level set to Installer,
the
button was pressed
during disinfection operation.
12.4
Solving problems based on error
codes
When a problem happens, an error code appears on the user
interface. It is important to understand the problem and to take
countermeasure before resetting the error code. This should be
done by a licensed installer or by your local dealer.
This chapter gives you an overview of all error codes and the
content of the error code as it appears on the user interface.
For a more detailed troubleshooting guideline for each error, please
see the service manual.
12.4.1
Error codes: Overview
Error codes of the outdoor unit
Error code
Detailed error
code
A5
00
E1
00
E3
00
E5
00
E6
00
E7
00
E8
00
EA
00
H0
00
H3
00
Corrective action
Do NOT press the
button
while the disinfection function is
active.
Description
OU: High pressure cooling/Peak
cut/ freeze protection problem.
Please contact your dealer.
OU: PCB defect.
Power reset required.
Please contact your dealer.
OU: Actuation of high pressure
switch (HPS).
Please contact your dealer.
OU: Overheat of inverter
compressor motor.
Please contact your dealer.
OU: Compressor startup defect.
Please contact your dealer.
OU: Malfunction of outdoor
unit fan motor.
Please contact your dealer.
OU: Power input overvoltage.
Please contact your dealer.
OU: Cool/heat switchover
problem.
Please contact your dealer.
OU: Voltage/current sensor
problem.
Please contact your dealer.
OU: Malfunction of high
pressure switch (HPS)
Please contact your dealer.
RRLQ004~008CA + RHBH/X04+08CB
ROTEX HPSU low temperature Bi‑bloc
4P384979-1C – 2017.04
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