*****INTERNAL*****30 R_D proof- 26.10.2022 / 09:15:46- VaillantGroup\DOC-agt\Brand\VIH_QW_190_6\ENG\OI-II_GB_0020291525
0020291525_04 Installation and maintenance instructions
61
Code
Meaning
Cause
Remedy
F.1120
Immersion heater: Phase failure
–
Electric back-up heater defective
–
Poorly tightened electrical connec-
tions
–
Mains voltage too low
–
Check the electric back-up heater
and its power supply
–
Check the electrical connections
–
Measure the voltage at the electrical
connection for the electric back-up
heater
F.9998
Connection fault: Heat pump
–
eBUS cable not connected or con-
nected incorrectly
–
Outdoor unit without supply voltage
–
Check the connection pipes between
the power supply PCB and control
PCB on the indoor and outdoor unit
K
5.4 kW back-up heater at 230 V and at 400 V
Internal control of the output
levels at 230 V and at 400 V
Power consumption
Set value
0
0.0 kW
1
0.7 kW
1 kW
2
1.2 kW
3
1.8 kW
2 kW
4
2.2 kW
3 kW
5
3.2 kW
6
3.8 kW
4 kW
7
4.7 kW
5 kW
8
5.4 kW
6 kW
L
Inspection and maintenance work
#
Maintenance work
Interval
1
Checking the pre-charge pressure of the expansion vessel
Annually
2
Cleaning the domestic hot water cylinder
If required, at least every
2 years
3
Check that the prioritising diverter valve can move easily (visually/audibly)
Annually
4
Checking the electronics boxes, removing dust from the ventilation slits
Annually
M
Characteristic values for the internal temperature sensors, hydraulic circuit
Sensors: TT620 TT650
Temperature (°C)
Resistance (ohms)
0
33400
5
25902
10
20247
15
15950
20
12657
25
10115
30
8138
35
6589
40
5367
45
4398
50
3624
55
3002
60
2500
65
2092
70
1759
75
1486
