Compressor Hysteresis; Enabling The Electric Back-Up Heater; Setting The Anti-Legionella Function; Purging - Vaillant VWL 57/5 IS Operating, Installation And Maintenance Instructions

7.9

Compressor hysteresis

The heat pump is switched on and off via the compressor
hysteresis for heating mode and also for energy balancing.
When the compressor hysteresis is above the target flow
temperature, the heat pump is switched off. When the hys-
teresis is below the target flow temperature, the heat pump
starts up again.
7.10

Enabling the electric back-up heater

On the system control, you can select whether the electric
back-up heater is to be used for heating mode, domestic
hot water mode or both modes. Set the maximum output for
the electric back-up heater at the indoor unit's control panel
here.
▶
Activate the internal electric back-up heater with one of
the following output levels.
▶
Ensure that the maximum output for the electric back-up
heater does not exceed the output of the fuse protection
for the household electricity system (for rated currents,
see Technical Data).
Note
Otherwise, the home's internal circuit breaker
may trigger if, when there is insufficient heat
source output, the electric back-up heater that
is not derated is switched on.
▶
You can find the output levels for the electric back-up
heater in the tables in the appendix.
5.4 kW back-up heater (→ Page 57)
8.54 kW back-up heater at 230 V (→ Page 57)
8.54 kW back-up heater at 400 V (→ Page 58)
7.11

Setting the anti-legionella function

▶
Set the anti-legionella function using the system control.
To ensure sufficient legionella protection, the electric back-
up heater must be activated.
7.12

Purging

You can use the installation assistant to run through the pur-
ging programmes.
▶
To do this, read the purging section. (→ Page 36)
7.13

Calling up the installer level

1. Press and at the same time.
Navigate to Menu → Installer level and confirm by
2.
pressing (OK).
3. Set the value 17 (code) and confirm by pressing
0020257319_02 Hydraulic station Installation and maintenance instructions
7.14

Restarting the installation assistants

You can restart the installation assistant at any time by call-
ing it up in the menu.
Menu → Installer level → Start inst. assistant.
7.15

Calling up statistics

Menu → Installer level → Test menu → Statistics
You can use this function to call up the statistics for the heat
pump.
7.16

Using check programmes

You can call up the check programmes via Menu → Installer
level → Test menu → Check programmes.
You can activate various special functions in the product by
using various check programmes.
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.
7.17

Carrying out the actuator test

Menu → Installer level → Test menu → Sensor/actuator
test
You can check that the components of the heating installa-
tion are functioning correctly using the sensor/actuator test.
You can actuate more than one actuator at a time.
If you do not select anything to change, you can have the
current control values for the actuators and the sensor val-
ues displayed.
You can find a list of the sensor characteristic values in the
appendix.
Characteristic values for the temperature sensor, refrigera-
tion circuit (→ Page 58)
Characteristic values for the internal temperature sensors,
hydraulic circuit (→ Page 59)
Characteristic values for the VRC DCF outdoor temperature
sensor (→ Page 61)
7.18

Starting up the optional system control

The following work for starting up the system was carried
out:
–
The system control and the outdoor temperature sensor
have been installed and wired.
–
Start-up of all system components (except for the system
.
control) is complete.
Follow the installation assistant and the operating and install-
ation instructions for the system control.
Start-up 7
37