Hkoenig bw1890 Manuel D'instructions page 11

Put 800ml water into the cooling cavity or pour the water to the
5.
max mark (Show as figure 8) (It can work without water, but it
can't display the best performance).
Note: Make sure the drain switch is at "Off" position, and no extra
objects in the cooling cavity.
The max
water level
line
Figure 8
B. OPERATION
Universal 5L beer keg
Before piercing the plug on the top of the keg, you must always
1.
follow the instructions marked on the keg to eliminate the excess
gas and ensure that the keg has rested long enough to avoid
foam coming out through the tap faucet.
Uprightly direct the piercing pin against the sealant on the upper
2.
center of the keg (maybe you need to tear off the marking ring
or change a proper sealant), press the piercing pin/keg lifter to
poke the sealant and then push the piercing pin all immerse in
the keg quickly. To assemble the tap mechanism until you hear
a "Ka" sound that will indicate the tap mechanism fixes on the
beer keg.
Figure 9