Daikin Altherma 3 H MT W, Installer'S Reference Manual

Page: 257 / 296

14 | Troubleshooting
Installer reference guide
257
EPRA08~W1 + ETBH/9W
Daikin Altherma 3 H MT W
4P634885-1 – 2021.03
Error code Description
UA-21 Extension/hydro mismatch problem
UF-00 Reversed piping or bad communication wiring
detection
UJ-14 AF communication error
UJ-20
AF warning
UJ-26
AF caution
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 Reheat only or Schedule + reheat mode 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 Schedule only mode is selected, it is recommended to program an
Eco
action 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 rate
20 l/min
INFORMATION
Error AJ-03 is reset automatically from the moment there is a normal tank heat-up.
INFORMATION
If an U8‑04 error occurs, the error can be reset after a successful update of the
software. If the software is not successfully updated then you must make sure that
your USB device has the FAT32 format.
INFORMATION
If the booster heater overheats and is disabled by the thermostatic safety, the unit
will not give an error directly. Check if the booster heater is still in operation if you
experience one or more of the following errors:
▪
Powerful operation takes a very long time to heat up and the error code AJ-03 is
displayed.
▪
During anti-legionella operation (weekly), the error code AH-00 is displayed
because the unit cannot reach the requested temperature required for tank
disinfection.
INFORMATION
A malfunctioning booster heater will have an impact on energy metering and power
consumption control.