Fault diagnosis and rectification
102
Installation instructions geoTHERM 0020051574_04
11
11.5
Fault with permanent switch-off
The heat pump is switched off after the occurrence of a
critical fault. After the cause of the faulty has been recti-
fied, the heat pump can only be started again by resetting
the fault (deleting the Error History)(see Menu I 1).
An exception applies in the case of fault 90 and 91. These
do not have to be reset.
When the cause of the fault has been rectified, the heat
pump restarts.
Emergency mode
Depending on the type of the fault message, you may
be able to set the heat pump to continue running in an
emergency mode via an external electric auxiliary heating
system or an external boiler until the cause of the fault has
been rectified. You can find out from (
¬
Tab.
11.4
) for which
fault messages emergency operation is possible.
For emergency operation, it is necessary that the hydraulic
integration of the auxiliary heating system is guaranteed
and an integrated auxiliary heating system has also been
activated.
>
Check whether in Menu A3 (
¬
Tab.
9.9
) an auxiliary heat-
ing system has not been locked. The setting “none” locks
all installed emergency functions and frost protection
functions of an auxiliary heating system. The factory set-
ting is “none”. If an external auxiliary heating system is
connected, you can set “DHW+CH” here.
>
For emergency operation, set the parameters of the aux-
iliary heating system for “Heating mode” and “Hot water
mode” to “CH only” in Menu C7 (
¬
Tab.
9.6
).
In the case of a fault with consequent permanent switch-off,
the following parameters appear in the display under the
fault message “Low pressure switch-off”:
– Reset (YES/NO)
Deletes the fault message and enables compressor oper-
ation.
– DHW priority (YES/NO)
Enables auxiliary heating hot water mode.
– CH priority (YES/NO)
Enables auxiliary heating for heating mode.
Emergency operation can be activated either for heating
mode (YES), hot water mode (YES) or for both (YES/YES).
Note that emergency operation which has been activated
manually must also be deactivated manually,
otherwise this function remains active.
The emergency operation function is otherwise only
disconnected by:
– Disconnection of the controller circuit board power sup-
ply (power failure in the mains power supply or discon-
nection via domestic fuses/circuit breakers) or
– RESET of the software (I4) or
– Resetting the fault message
The heat pump is then restarted with compressor opera-
tion.
You can see from the basic display whether the emergency
operation function is (still) because only the vertical arrow
(auxiliary heating system) is shown in black, whereas the
horizontal arrow (environmental energy) appears in white.
>
After the fault has been rectified, switch off emergency
operation by selecting the setting “Reset” “YES” in the
display “Low pressure switch-off”
(Turn the adjuster fully to the left).
