Observing Inspection And Maintenance Intervals; Preparing For Inspection And Maintenance; Checking The Admission Pressure Of The Expansion Vessel; Checking And Correcting The Filling Pressure Of The Heating Installation - Vaillant VWL 57/5 IS Operating, Installation And Maintenance Instructions

11.4 Observing inspection and maintenance
intervals
▶
Use the "Inspection and maintenance work" table in the
appendix.
▶
Adhere to the minimum inspection and maintenance in-
tervals. Carry out all of the work that is mentioned.
▶
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.
11.5

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.
11.6 Checking the admission pressure of the
expansion vessel
1
1. Close the service valves and drain the heating circuit.
(→ Page 41)
2. Measure the pre-charge pressure of the expansion ves-
sel (1) at the valve (2).
Result:
Note
The required pre-charge pressure of the
heating installation may vary depending
on the static pressure (0.1 bar per metre in
height).
Pre-charge pressure is below 0.75 bar (±0.1 bar/m)
▶
Fill the expansion vessel with nitrogen. If nitrogen is
not available, use air.
3. Fill the heating circuit. (→ Page 35)
0020257319_02 Hydraulic station Installation and maintenance instructions
11.7 Checking and correcting the filling pressure
of the heating installation
If the filling pressure falls below the minimum pressure, a
maintenance message is shown on the display.
– Min. heating circuit pressure: ≥ 0.05 MPa (≥ 0.50 bar)
▶
Top up the heating water in order to start up the heat
pump again; Filling and purging the heating installation
(→ Page 35).
▶
If you notice frequent pressure losses, determine and
eliminate the cause.
11.8

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.
11.9

Completing inspection and maintenance

Warning.
Risk of burns due to hot and cold com-
ponents.
There is a risk of burns from any uninsu-
lated pipelines and from the electric back-
up heater.
▶
Before starting up the unit, install any cas-
ing sections that have been removed.
1. Start up the heat pump system.
2. Check that the heat pump system is working without
any problems.

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 25)
3. Connect a hose to the filling device (1) and guide the
free end of the hose to a suitable drainage point.
Draining 12
1
41