Checking The Filling Pressure Of The Heating Installation; 12.17 Checking The Quality Of The Heating Water; Completing Inspection And Maintenance Work; 12.19 Checking The Product For Leak-Tightness - Vaillant ecoTEC plus VU 6/5-5 Series Installation And Maintenance Instructions Manual

5. Purge the heating installation. (→ Page 35)
12.16 Checking the filling pressure of the heating
installation
1. Check the filling pressure of the heating installation, top
it up with heating water, if necessary, and purge it.
2. Fill the heating installation. (→ Page 35)
3. Purge the heating installation. (→ Page 35)

12.17 Checking the quality of the heating water

▶
Check the quality of the heating water: Clarity (clouding),
correct inhibitor and pH value. (→ Page 33)
12.18 Completing inspection and maintenance
work
▶
Start a test operation after the maintenance.
▶
Check the heating mode and, if required, the domestic
hot water generation (if available).
▶
Carry out a gas family check. (→ Page 33)
▶
Check the gas flow pressure. (→ Page 36)
▶
Check and, if required, adjust the CO₂ content and the
CO/CO₂ ratio (air ratio setting). (→ Page 37)
▶
If required, reset the maintenance interval. (→ Page 39)
▶
Install the front casing.
▶
Fill out the relevant Service Record section in the Bench-
mark Checklist.

12.19 Checking the product for leak-tightness

▶
Check that the product is leak-tight. (→ Page 38)

13 Troubleshooting

13.1

Checking service messages

appears if you have set a maintenance interval, for ex-
ample, and this has passed or a service message is issued.
The product is not in fault mode.
▶
Navigate to Menu → Live monitor and confirm by press-
ing .
Condition: S.40 is displayed
The product is in Comfort protection mode. The product con-
tinues to run with restricted comfort after it has detected a
fault.
▶
To establish whether or not a component is defective,
read the fault memory. (→ Page 45)
Note
If no fault message is present, the product will
automatically switch back to normal operating
mode after a certain time.
0020244997_07 Installation and maintenance instructions
13.2

Eliminating faults

▶
If fault messages (F.XX) occur, eliminate the faults by
checking the table in the appendix or using the function
menu or the check programmes.
Overview of fault codes (→ Page 60)
Function menu – Overview (→ Page 63)
Check programmes – Overview (→ Page 63)
If several faults occur at the same time, the display shows
the corresponding fault messages for two seconds each in
alternation.
▶
Press (max. three times) to restart the product.
▶
If you are unable to eliminate the fault and the fault re-
curs despite reset attempts, contact customer service.
13.3

Calling up and clearing the fault memory

The last 10 fault messages are stored in the fault memory.
▶
Navigate to the Fault list menu.
◁
The display shows the number of faults that have
occurred, the fault numbers and the corresponding
plain text display.
▶
Press or to call up individual fault messages.
▶
Press twice to delete the fault list.
13.4

Resetting parameters to factory settings

Navigate to Menu → Installer level → Diagnostics
1.
menu → D.096 Reset to factory settings? and con-
firm by pressing .
2. Set the diagnostics code to 1, and confirm by pressing
.
13.5

Preparing the repair work

1. Decommission the product.
2. Disconnect the product from the power grid.
3. Remove the front casing. (→ Page 23)
4. Close the gas stopcock.
5. Close the service valves in the heating flow and in the
heating return.
6. Close the service valve in the cold water pipe.
7. Drain the product if you want to replace water-carrying
components of the product.
8. Ensure that water does not drip on live components
(e.g. the electronics box).
9. Use only new seals.
13.5.1 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 void the conformity of
the product and it will therefore no longer comply with the
applicable standards.
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.
45