LG THERMA V Series Installation Manual page 27

Heating system
For unobstructed and safe operation, it is important to have a heat accumulator with a minimal
volume of 40 l (integrated in the IDU). The accumulator is needed for hydraulic balancing, ensuring
unobstructed flow and defrosting. A larger accumulator ensures a more balanced temperature of
heating and more comfort.
When installing an additional larger heat accumulator, it is necessary to close the ball valve in the
indoor unit. The location of the closing valve is indicated on the picture below.
Installation of Indoor Unit
C
C : Ball valve
Installation Manual 27