OPERATING AND INSTALLATION MANUAL HEAT PUMP COMBI UNIT PKOM4 PAGE 50
USER
GENERALSPECIALIST PERSONNEL
26
High pressure
cooling circuit
service water
High-pressure switch in the
service water cooling circuit
has been activated
Check terminal E2 on heat pump board N3 Restore terminal contacts
Check pressure switch B35 using a measuring de-
vice at terminals E2 on the heat pump board: Ter-
minal E2/1 24VDC, terminal E2/2 24VDC PLEASE
NOTE: Pressure in the service water cooling circuit
must be below 20bar!
No voltage on terminal E2/2 – replace heat
pump board N3
No voltage on terminal E2/1 – continue
carrying out troubleshooting on the basis of
the following items
Check the connection of pressure switch B35 Restore contact
Check the cable Replace the cable
Check pressure switch B35 using a measuring
device, pull plug E2 on heat pump N3 and measure
the resistance. The pressure switch must be un-
interrupted in its normal state (NC) PLEASE NOTE:
Pressure in the service water cooling circuit must
be below 20bar!
Replace the pressure switch
Check the temperature sensor tank bottom as in the case of error 18
Too much refrigerant in the service water cooling
circuit
Extract refrigerant and refill with refrigerant
No error detectable Please contact your service partner
27 Extract air fan
The extract air fan does not
work or is working at an
incorrect speed
Check terminals K2 (voltage supply) on ventilation
board N2
Restore terminal contacts
Check terminals U2 (control signals) on ventilation
board N2
Restore terminal contacts
Check fuse F4 (24 VDC voltage supply) on main
board N1 – table 3
Replace fuse
Check the voltage supply on ventilation board
N2: between terminals K2/1 and K2/2, 230 VAC
must be measured. CAUTION: Heat pump must be
switched on, automatic mode must be selected
and all faults must be reset
a) Check fuse F1 on main board N1
b) Check terminals H2 on main board N1
c) Check terminals H4 on ventilation board
N2
d) Replace ventilation board N
Check fan M2 with regard to free run and damage Replace fan
No error detectable
a) Replace the ventilation board
b) Contact your service partner
28 Outdoor air fan
The outdoor air fan does
not work or is working at an
incorrect speed
Check terminals K1 (voltage supply) on ventilation
board N2
Restore terminal contacts
Check terminals U1 (control signals) on ventilation
board N2
Restore terminal contacts
Check fuse F4 (24 VDC voltage supply) on main
board N1 – table 3
Replace fuse
Check the voltage supply on ventilation board
N2: between terminals K1/1 and K1/2, 230 VAC
must be measured. CAUTION: Heat pump must be
switched on, automatic mode must be selected
and all faults must be reset
Replace ventilation board N2
Check fan M1 with regard to free run and damage Replace fan
No error detectable
a) Replace the ventilation board
b) Contact your service partner
29
Outdoor air /
exhaust air flap
The position of the fins from
the outdoor air/exhaust air
flap is incorrect
Check terminals U3 on ventilation board N2 Restore terminal contacts
Check flap drive M4 for ease of operation Replace flap drive M4
Check the multi-leaf damper for ease of operation Replace the multi-leaf damper
Ensure that flap drive M4 is mounted correctly.
Set the system to "O" at the display, wait for 5
minutes. The multi-leaf damper must be closed.
Mount flap drive M4 on the closed multi-leaf
damper
Check fuse F4 (24 VDC voltage supply) on main
board N1 – table 3
Replace fuse
No error detectable
a) Replace the ventilation board
b) Contact your service partner
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