17
"Service/
fault"
symbol
Possible causes of fault
Note
Remedy
The appliance is locked out due to
being switched off frequently for
safety reasons (high pressure).
The safety pressure limiter has re-
sponded 5 times in 5 hours.
Contact the service department. The appli-
ance can only be unlocked with a service pro-
gramming unit. Activate emergency heating
mode.
The appliance has ascertained
that the hot water cylinder has
not been heated for 13
hours, de-
spite there being a demand.
The compressor is permanently locked
out.
Check whether there is excessively high, con-
tinuous hot water draw-off or if a hot water
circulation line is installed. Check whether
there is a fault in the refrigerant circuit. Con-
tact the service department. Activate emer-
gency heating mode. In the case of this fault,
the result of carrying out a reset by interrupt-
ing the power supply is that emergency heat-
ing mode can only be activated again after
13
hours.
Evaporator temperature <
-20
°
C;
air flow rate too low
The compressor is permanently locked
out.
Check whether the fan is faulty. Check whether
the evaporator is contaminated. Check wheth-
er the air intake or air discharge is blocked.
The compressor can only be unlocked by
means of a reset carried out by interrupting
the power supply. Check whether there is an
air flow rate after carrying out the reset by in-
terrupting the power supply.
As a qualified contractor you can bypass the compressor lockout time and reset several faults. Switch the
power supply OFF and back ON again via the fuse/MCB in the domestic distribution board.
If the "service/fault" symbol is flashing, you can continue to use the appliance temporarily by activating emer-
gency heating mode. Press and hold the "Rapid heat-up" button for two seconds. See chapter "Operation
/
'Rapid heat-up' button
/ Emergency heating mode".
There are some cases in which emergency heating mode cannot be activated. For example, if the hot water
cylinder is empty or temperature sensors are faulty, the appliance locks out the electric emergency/booster
heater.
Resetting the safety pressure limiter
The safety pressure limiter responds if the pressure in the refrigerant circuit exceeds the permissible maximum
value. If the safety pressure limiter responds 5 times in 5
hours, compressor operation is blocked.
f
f
Eliminate the cause of the increased pressure in the refrigerant circuit.
f
f
Wait approx.
5-15
minutes for the appliance to equalise the pressure.
The appliance can only be unlocked with a service programming unit.
Resetting the high limit safety cut-out
If the hot water cylinder is overheated, the high limit safety cut-out switches off the electric emergency/
booster heater to protect the appliance.
D
00000
3
9
3
5
2
1
1 Reset button for high limit safety cut-out
f
f
Once the cause of the fault has been removed, press the reset button of the high limit safety cut-out on
the rod thermostat. To do so, remove the appliance cover.
