Viessmann VITOCAL 250-A - Filling and Venting the System; Emergency Mode

49
A
B
R290
Fig. 17
Safety valve
Non-return valve
Heating water filter in the ball valve
Heating water side
Condenser
A
Quick-action air vent valve
B
Float air vent valve
Ball valve with filter
The condenser can be damaged by particles in the
heating water. To filter out any particles upstream of
the condenser, a ball valve with filter is installed in the
heating water return of the outdoor unit. Clean this fil-
ter regularly and replace it if necessary. The ball valve
is open during operation and is closed to clean the fil-
ter.
Heating filter
A heating filter is used to filter particles and sludge out
of the heating water before it enters the heat pump.
The filter properties of the heating filter with magnetite
separation (accessories) are matched to the heat
pump.
Recommendation: Installation of 2 heating filters
1. Between the indoor and outdoor unit, before the
inlet to the outdoor unit:
■
Essential requirement in the case of heating sys-
tem modernisations
■
Strongly recommended for new build
2. Additionally in the secondary circuit return, immedi-
ately before the inlet to the indoor unit
Filling and venting the system
To ensure that the float air vent valve works correctly,
the system must be completely filled and vented in the
right order during commissioning. This ensures that
the position of the 4/3-way valve matches the system
component that is currently to be filled and vented.
Heat pump installation and service instructions
Note
■
Observe the requirements for the fill and top-up
water. Only use heating water without antifreeze.
■
No parameters need to be set for the float air vent
valve.
Emergency mode
If the outdoor unit is not available, emergency mode
can be switched on temporarily.
In emergency mode, the available booster heaters pro-
vide room heating and DHW heating. In emergency
mode, room cooling is always switched off.
Emergency mode can be switched on in the following
cases:
■
There is a fault in the outdoor unit, e.g. a mechanical
defect in the fan.
■
The outdoor unit is not yet connected, e.g. during the
construction phase. In this case, the two connections
at the indoor unit to and from the outdoor unit must
be hydraulically connected.
Installation and service instructions for the
heat pump
Function description
Float air vent valve (cont.)
6218234
Functions