*****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
43
5.
Remove the capillary tube from the temperature sensor
on the electric back-up heater.
6.
Remove both screws and remove the safety cut-out
with the retainer from the product.
7.
Install the new safety cut-out in reverse order.
10.9
Resetting parameters to factory settings
▶
Select
Menu
→
Menu
→
Installer level
→
Resets
to reset
all of the parameters at the same time and to restore the
product to the factory settings.
11 Inspection and maintenance
11.1
Procuring spare parts
The original components of the product were also certified
by the manufacturer as part of the declaration of conformity.
If you use other, non-certified or unauthorised parts during
maintenance or repair work, this may result in the product no
longer meeting the applicable standards, thereby voiding the
conformity of the product.
We strongly recommend that you use original spare parts
from the manufacturer as this guarantees fault-free and safe
operation of the product. To receive information about the
available original spare parts, contact the contact address
provided on the back page of these instructions.
▶
If you require spare parts for maintenance or repair
work, use only the spare parts that are permitted for the
product.
11.2
Checking maintenance messages
If the
symbol is shown in the display, the product requires
maintenance work or the product is in comfort protection
mode.
▶
To obtain further information, call up the
Live Monitor
.
▶
Carry out the maintenance work that is listed in the table.
Maintenance messages (
Condition
:
Lhm.XX
is displayed
The product is in Comfort protection mode. The product has
detected a permanent fault and continues to run with restric-
ted comfort.
▶
To determine which component is defective, read the
fault memory (
Note
If a fault message is present, the product re-
mains in comfort protection mode after it is re-
set. After the product is reset, the fault mes-
sage is displayed first before the message
Limp home mode (comfort protection)
ap-
pears again.
▶
Check the component that is displayed and replace it, if
required.
11.3
Observing inspection and maintenance
intervals
▶
Adhere to the minimum inspection and maintenance in-
tervals. Carry out all of the work that is listed in the "In-
spection and maintenance work" table in the appendix.
▶
Carry out maintenance work on the product at an earlier
point if the results of the inspection that was carried out
during previous maintenance make this necessary.
11.4
Preparing for inspection and maintenance
Observe the basic safety rules before carrying out inspection
and maintenance work or installing spare parts.
▶
Switch off the product.
▶
Disconnect the product from the power supply.
▶
Secure the product against being switched back on
again.
▶
When working on the product, protect all electric com-
ponents from spraying water.
▶
Remove the front casing.
11.5
Using check programmes
You can call up the check programmes via
Menu
→
Installer
level
→
Test menu
→
Check programme
.
If the product is in error condition, you cannot start any check
programmes. You can detect an error condition by the fault
symbol shown in the left bottom corner of the display. You
must first reset.
To end the check programmes, you can press
Cancel
at any
time.
11.6
Checking the pre-charge pressure of the
expansion vessel
1.
Close the service valves and drain the heating circuit.
(
1
2.
Measure the pre-charge pressure of the expansion
vessel
(1)
at the valve
(2)
.
3.
If the pressure is below 0.075 MPa (0.75 bar)
(depending on the static pressure level of the heating
installation), use nitrogen to fill the expansion vessel.
4.
Fill the heating circuit.
