Symptom: The Pressure At The Tapping Point Is Temporarily Unusual High; Symptom: Decoration Panels Are Pushed Away Due To A Swollen Tank; Symptom: Tank Disinfection Function Is Not Completed Correctly (Ah-Error); Solving Problems Based On Error Codes - Daikin Altherma EHVH/X16S18+26CA Installer's Reference Manual

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)
12.2.7 Symptom: The pressure at the tapping
point is temporarily unusual high
Possible causes
Failing or blocked pressure relief
valve.
12.2.8 Symptom: Decoration panels are pushed
away due to a swollen tank
Possible causes
Failing or blocked pressure relief
valve.
12.2.9 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
12.3

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.
Installer reference guide
64
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 >
Setpoint mode > 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 >
Setpoint mode > 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.
For a more detailed troubleshooting guideline for each error, please
see the service manual.
12.3.1

Error codes: Overview

Error codes of the indoor unit
Error code Detailed error
code
A1 00
AA 01
UA 00
7H 01
89 01
8H 00
8F 00
C0 00
U3 00
81 00
C4 00
80 00
U5 00
U4 00
AC 00
EC 00
ERHQ011~016BA + ERLQ011~016CA + EHVH/X16S18+26CA
Description
Zero cross detection problem.
Power reset required.
Please contact your dealer.
Backup heater overheated.
Power reset required.
Please contact your dealer.
Indoor unit, outdoor unit
matching problem.
Power reset required.
Water flow problem.
Heat exchanger frozen.
Abnormal increase BUH
outlet water temperature.
Abnormal increase BUH
outlet water temperature (DHW).
Flow sensor/switch malfunction.
Please contact your dealer.
Under floor heating screed
dryout function not completed
correctly.
Leaving water temperature
sensor problem.
Please contact your dealer.
Heat exchanger temperature
sensor problem.
Please contact your dealer.
Returning water temperature
sensor problem.
Please contact your dealer.
User interface
communication problem.
Indoor/outdoor unit
communication problem.
Booster heater overheated.
Please contact your dealer.
Abnormal increase tank
temperature.
Daikin Altherma - Low Temperature Split
4P313777-1C – 2012.11