OPERATING AND INSTALLATION MANUAL HEAT PUMP COMBI UNIT PKOM4 PAGE 48
USER
GENERALSPECIALIST PERSONNEL
Error
No.
Fault signal What does that mean? Troubleshooting Correction
4
Error four-way
valve
Cooling or heating perfor-
mance too low
Check the airflows
Replace polluted filters, clear blocked
airways
Check evaporator in the exhaust air Induce manual defrosting
The four-way valve
is not working properly
Check terminals 1 and 2 at relay K11 on the heat
pump board (N3)
Restore terminal contacts
Check the connections on the coil of the magnetic
valve (M12)
Restore terminal contacts
Check cable W64 Replace cable W64
Measure the voltage at terminals 1 and 2 of relay
K11 - 0V in heating mode/230V in cooling mode
Replace heat pump board
Check the magnetic coil of the four-way valves
(M12) using a measuring device – the resistance
value should be ~ 1.5kohms
Replace coil of magnetic valve
Check whether the evaporator is frozen over Induce manual defrosting
Check the measuring hoses for dierential pres-
sure measurement at pressure transducer P3 on
heat pump board N3
Clean the measuring hoses
No error detectable Please contact your service partner
5
T1 - supply
sensor
The supply air temperature
sensor is defective or the
cable is broken
Check terminal T1 on ventilation board N2 Restore terminal contacts
Check the temperature sensor using a measuring
device – resistance value according to table 1
Replace the sensor
No error detectable Please contact your service partner
6
T2 - room
sensor
The temperature sensor on
the display is defective
Check the display
No error detectable Please contact your service partner
7
T3 - outdoor air
sensor
The outdoor air temperature
sensor is defective or the
cable is broken
Check terminal T3 on ventilation board N2 Restore terminal contacts
Check the temperature sensor using a measuring
device – resistance value according to table 1
Replace the sensor
No error detectable Please contact your service partner
8
T4 - exhaust air
sensor
The exhaust air temperature
sensor is defective or the
cable is broken
Check terminal T4 on ventilation board N2 Restore terminal contacts
Check the temperature sensor using a measuring
device – resistance value according to table 1
Replace the sensor
No error detectable Please contact your service partner
9
T5 - sensor up-
stream of WT3
The temperature sensor
upstream of heat exchanger
WT3 in the exhaust air is de-
fective or the cable is broken
Check terminal T5 on heat pump board N3 Restore terminal contacts
Check the temperature sensor using a measuring
device – resistance value according to table 1
Replace the sensor
No error detectable Please contact your service partner
10
T6 - sensor T6
in WT3
The temperature sensor of
heat exchanger WT3 in the
exhaust air is defective or the
cable is broken
Check terminal T6 on heat pump board N3 Restore terminal contacts
Check the temperature sensor using a measuring
device – resistance value according to table 1
Replace the sensor
No error detectable Please contact your service partner
11
T7 - extract air
sensor
The extract air temperature
sensor is defective or the
cable is broken
Check terminal T7 on ventilation board N2 Restore terminal contacts
Check the temperature sensor using a measuring
device – resistance value according to table 1
Replace the sensor
No error detectable Please contact your service partner
12
T8 - sensor
compliant with
VHR
The temperature sensor of
the pre-heating battery in the
outdoor air is defective or the
cable is broken
Check terminal T8 on ventilation board N2 Restore terminal contacts
Check the temperature sensor using a measuring
device – resistance value according to table 1
Replace the sensor
No error detectable Please contact your service partner
13
T9 - sensor
solar/KHR
The temperature sensor on
the solar collector or down-
stream of the duct-heating
battery in the supply air
is defective or the cable is
broken
Check terminals T9/1 and 2 of PT1000 sensor or
terminals T9/2 and 3 of NTC sensor on the main
board N1
Restore terminal contacts
Check the temperature sensor using a measuring
device – resistance value according to table 1 for
NTC sensors or table 2 for PT1000 sensors
Replace the sensor
No error detectable Please contact your service partner
15.10 ERROR DESCRIPTION
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