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LWZ 304 Trend | LWZ 404 Trend | LWZ 304 Integral |
39
INSTALLATION
Troubleshooting
no. Fault
Appliance response
Cause
Remedy
28
Flow temperature
sensor in heating
circuit
The heating system switches
over to heating mode subject to
return temperature. The electric
emergency/booster heater out-
put cannot be calculated.
The measured sensor values
have been constantly outside the
permissible range for a specified
period.
Press the electronics reset button for one second. If this faults oc-
curs repeatedly, notify customer support.
29
DHW temperature
sensor
DHW heating is blocked.
The measured sensor values
have been constantly outside the
permissible range for a specified
period.
Press the electronics reset button for one second. If this faults oc-
curs repeatedly, notify customer support.
30
Software version
Press the electronics reset button. If this faults occurs repeatedly,
notify customer support. The software version does not match the
hardware version.
31 RAM
Press the electronics reset button. If this faults occurs repeatedly,
notify customer support. Replace the control unit.
32 EEProm
Press the electronics reset button. If this faults occurs repeatedly,
notify customer support. Replace the control unit.
33
Extract air humidity
sensor
The actual values captured by a
humidity sensor are continuously
outside the permissible range for a
defined period.
Press the electronics reset button. If this faults occurs repeatedly,
notify customer support.
34 Flow sensor
Press the electronics reset button. If this faults occurs repeatedly,
notify customer support.
36
Min. flow rate
For 2 hours the flow rate has
been < 5 l/min.The electric
emergency/booster heater will
be blocked. Only frost protection
remains effective.
Select a higher pump speed. Open the heating circuits. Balance
the heating circuits. Isolate the appliance across all poles from the
mains power for approx. one minute. If the pump repeatedly fails to
start, inform customer support.
37
Min. water pressure
The overpressure is less than
0.05 MPa (0.5 bar). At the same
time, the minimum flow rate has
not been achieved. The electric
emergency/booster heater will
be blocked.
This fault may occur following
venting or due to leaks.
Top up with water.
40
Float switch, bottom
panel
The heat pump and the ventila-
tion are switched off.
The cause is the defrost pan over-
flowing or leaks in the heating or
DHW circuit of the appliance. This
fault may reset automatically.
Check for leaks. Check the float switch is working correctly.
50
Sensor on heat
pump return
Control of the appliance con-
tinues despite this fault. The
amount of heat in the compres-
sor cannot be calculated.
The measured sensor values have
been outside the permissible
range for a specified period.
Press the electronics reset button for one second. If this faults oc-
curs repeatedly, notify customer support. Replace the sensor.
51
Sensor on heat
pump flow
Control of the appliance con-
tinues despite this fault. The
amount of compressor heat and
the output of the electric emer-
gency/booster heater cannot be
calculated.
The measured sensor values have
been outside the permissible
range for a specified period.
Press the electronics reset button for one second. If this faults oc-
curs repeatedly, notify customer support. Replace the sensor.
52
Sensor on condenser
outlet
Control of the appliance contin-
ues despite this fault.
The measured sensor values have
been outside the permissible
range for a specified period.
Press the electronics reset button for one second. If this faults oc-
curs repeatedly, notify customer support. Replace the sensor.