0020297933_07 Installation and maintenance instructions
63
25
30
20
15
10
0
5
10
15
20
25
30
35
35
40
45
50
A
B
A
Outdoor temperature
B
Heating water temper-
ature
3.12
Thawing mode
At outdoor temperatures below 5 °C, condensation on the
fins of the evaporator may freeze and frost may form. This
frost is automatically detected and is automatically thawed at
certain intervals.
The thawing occurs by reversing the refrigeration circuit
while the heat pump is operating. The heat energy that is
required for this is taken from the heating installation.
Correct thawing mode is only possible if the minimum
volume of heating water is available in the heating
installation:
Product
Activated back-up
heater
Deactivated back-
up heater
VWL 35/6 and
VWL 55/6
15 litres
40 litres
VWL 65/6 and
VWL 75/6
20 litres
55 litres
3.13
Safety devices
The product is equipped with technical safety devices. See
"Safety devices" graphic in the appendix.
If the refrigerant circuit pressure exceeds the maximum pres-
sure of 3.15 MPa (31.5 bar), the pressure switch temporarily
switches the product off. Following a waiting period, another
attempt is made to start it. After three failed start attempts in
succession, a fault message is displayed on the indoor unit's
control panel.
If the product is switched off, the crankcase housing heat-
ing is switched on when the compressor outlet temperat-
ure reaches 7 °C. This prevents possible damage caused
by switching the product back on.
If the temperature measured at the compressor outlet is
higher than the permissible temperature, the compressor
is switched off. The permissible temperature depends on the
evaporation and condensation temperature.
The pressure in the heating circuit is monitored using a pres-
sure sensor. If the pressure falls below 0.5 bar, a fault shut-
down occurs. If the pressure rises to above 0.7 bar, the fault
is reset again.
The heating circuit's circulation water volume is monitored
using a flow rate sensor. If no flow rate can be detected
when there is a heat demand when the circulation pump is
running, the compressor does not start up.
If the heating water temperature falls below 4 °C, the pro-
duct's frost protection function is automatically activated as
the heating pump is started.
4
Protective zone
4.1
Protective zone
The product contains R290 refrigerant. Note that this refri-
gerant has a higher density than air. In the event of a leak,
escaping refrigerant may collect near the ground.
The refrigerant must not collect in any way that may lead
to a dangerous, explosive, suffocating or toxic atmosphere.
The refrigerant must not get inside the building via building
openings. The refrigerant must not collect in grooves.
A protective zone is defined around the product. There must
be no windows, doors, light shafts, cellar entrances, escape
hatches, flat-roof windows or ventilation openings in the pro-
tective zone.
There must be no ignition sources, such as plug sockets,
light switches, lamps, electrical switches or other permanent
ignitions sources, in the protective zone.
The protective zone must not extend to adjacent buildings or
public traffic areas.
In the protective zone, you are not permitted to make any
subsequent structural alterations which infringe the stated
rules for the protective zone.
4.1.1
Protective zone for ground installation on
the premises
A
A
1000 mm
Dimension A is a clearance around the product.
