Notes On The Documentation 2; Observing Other Applicable Documents; Storing Documents; Validity Of The Instructions - Vaillant VWL 57/5 IS Operating, Installation And Maintenance Instructions

2 Notes on the documentation
2.1

Observing other applicable documents

▶
Always observe all the operating and installation instruc-
tions included with the system components.
2.2

Storing documents

▶
Pass these instructions and all other applicable docu-
ments on to the end user.
2.3

Validity of the instructions

These instructions apply only to:
Product
VWL 57/5 IS
VWL 77/5 IS
VWL 127/5 IS
2.4

Further information

▶
Scan the displayed code using your smartphone in order
to view further information about the installation.
◁
You are guided to installation videos.
3

Product description

3.1

Heat pump system

Design of a typical heat pump system with split technology:
0020257319_02 Hydraulic station Installation and maintenance instructions
Outdoor unit
VWL 35/5 AS
VWL 55/5 AS
VWL 75/5 AS
VWL 105/5 AS
VWL 125/5 AS

Notes on the documentation 2

1 2
1 Heat pump, outdoor unit
2 eBUS line
3 System control (op-
tional)
3.2

Safety devices

3.2.1 Frost protection function
The frost protection function for the system is controlled us-
ing the product itself or using the optional system control. If
the system control fails, the product guarantees limited frost
protection for the heating circuit.
3.2.2 Low-water pressure protection
This function continuously monitors the pressure of the heat-
ing water in order to prevent a possible loss of heating wa-
ter. If the water pressure falls below the minimum pressure,
an analogue pressure sensor switches off the product and
switches the other modules, where these exist, to standby
mode. The pressure sensor switches the product on again if
the water pressure reaches the operating pressure.
If the pressure in the heating circuit is ≤0.1 MPa (1 bar), a
maintenance message appears below the minimum operat-
ing pressure.
– Min. heating circuit pressure: ≥ 0.05 MPa (≥ 0.50 bar)
– Min. heating circuit operating pressure: ≥ 0.07 MPa
(≥ 0.70 bar)
3.2.3 Freeze protection
This function prevents the outdoor unit's evaporator from
freezing when the heat source temperature drops below a
certain value.
The outlet temperature of the heat source is constantly
measured. If the outlet temperature of the heat source falls
below a certain value, the compressor temporarily switches
off and displays a status message. If this fault occurs three
times in a row, it is switched off and a fault message is
displayed.
3.2.4 Pump blocking protection
This function prevents the pumps for heating water from
sticking. The pumps, which were out of operation for
3
4
5
6
4 Control for the indoor
unit
5 Heat pump, indoor unit
6 Refrigerant circuit
19