Symptom: The Pressure At The Tapping Point Is Temporarily Unusually High; Symptom: Tank Disinfection Function Is Not Completed Correctly (Ah-Error); Symptom: Boiler Abnormality Detection (Hj-11 Error); Symptom: Boiler/Hydrobox Combination Abnormality (Ua-52 Error) - Daikin Altherma H Hybrid EJHA04AAV3 Installer's Reference Manual

16.4.7 Symptom: The pressure at the tapping point is temporarily unusually high

16.4.8 Symptom: Tank disinfection function is NOT completed correctly (AH-error)

16.4.9 Symptom: Boiler abnormality detection (HJ-11 error)

16.4.10 Symptom: Boiler/hydrobox combination abnormality (UA-52 error)

EJHA04AAV3 + EHY2KOMB28+32AA
Daikin Altherma H Hybrid
4P531180-1D – 2025.03
Possible causes
Failing or blocked pressure relief valve.
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
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.
Possible causes
Communication cable problem
Boiler error
Possible causes
Boiler/hydrobox mismatch
Incompatibility of software
16 Troubleshooting
|
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
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 of the disinfection
function at least 4 hours later than the
last expected large hot water tapping.
This start-up can be set via the 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.
Do NOT press the button while the
disinfection function is active.
Corrective action
Mount the communication cable
between the gas boiler and the outdoor
unit properly.
Check the boiler display for error
information.
Corrective action
Make sure that the . setting is set to 0.
Update the boiler and hydrobox
software to the latest version.
Installer reference guide
209