Viessmann VITOCAL 151-A Installation And Service Instructions Manual page 147

Filling the refrigerant circuit
6. Affix a label to the heat pump in a clearly visible
position, containing the following information, with
date and signature:
■ Type of topped up refrigerant
■ Amount of topped up refrigerant
7. Carry out the leak test using an explosion-proof
refrigerant detector suitable for R290 (propane).
Draining the outdoor unit on the secondary side
If only the outdoor unit is to be drained, shut off the
hydraulic lines to the indoor unit.
3.
90°
2.
Fig. 88
(cont.)
8. Seal the sealing cap of the low pressure Schrader
valve: See "Outdoor unit maintenance: Overview of
internal components".
2. Open the check valve: Flow also in direction oppo-
site to arrow.
For this, rotate the slot by 90°(slot in direction of
flow).
Allow the heating water to fully drain from the out-
door unit.
3. Close the check valve: Flow only in direction of
arrow
For this, rotate the slot back by 90°(slot perpendic-
ular to direction of flow).
1.
Outdoor unit maintenance
147