Checking Maintenance Messages; Observing Inspection And Maintenance Intervals; Preparing For Inspection And Maintenance; Using Check Programmes - Vaillant VWL Series Operating Instructions Manual

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 (→ Page 52)
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 (→ Page 37).
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.
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.
0020291544_01 Hydraulic Station Installation and maintenance instructions
11.6 Checking the pre-charge pressure of the
expansion vessel
1. Close the service valves and drain the heating circuit.
(→ Page 39)
1
2. Measure the pre-charge pressure of the expansion ves-
sel at the valve (1).
3. If the pressure is below 0.075 (0.75 bar) (depending
on the static pressure of the heating installation), use
nitrogen to fill the expansion vessel.
4. Fill the heating circuit. (→ Page 34)
11.7

Checking the high-pressure switch-off

▶
Start check programme P.29 High pressure.
◁
The compressor starts and the flow rate monitoring
for the pump is deactivated.
▶
Block the heating circuit.
◁
The product is switched off by the high-pressure
switch-off.

12 Draining

12.1

Draining the product's heating circuit

1. Close the service valves in the heating flow and in the
heating return.
2. Remove the front casing. (→ Page 26)
3. Connect a hose to the filling device (1) and guide the
ends of the hose to a suitable drainage point.
4. Use manual actuation to move the prioritising diverter
valve to the "Heating circuit/domestic hot water cylinder"
position. (→ Page 33)
Draining 12
1
39