La Marzocco kb90 Series, Manual

Page: 16 / 144

EN
16
4. Machine Operation and Coffee Preparation
1) Starting the espresso machine
a) Filling the boilers with water
Once the installation procedures have been
completed, it is necessary to fill the boiler
tanks with water. Complete the following
procedure to properly fill the boiler tanks:
• Coffee boiler
The water flows inside the coffee boiler
directly, as soon as the water system and
water filter/softener taps (if present) are
opened. Since the inflow of water will
compress the air in the boiler it will be
necessary to remove or “bleed” the air
from the coffee boiler. All air must be
removed in order to completely “saturate”
the coffee boiler/group assemblies. To
remove the air from the boiler, “bleed the
groups”, it will be necessary to remove the
group cover from the top of the machine.
First remove the group tray from the top
of the machine exposing the cup tray.
Remove the screws securing the group
cover and then remove it. Once removed
the top of the groups will be exposed.
Loosen the bleed screws one at a time (see
fig.5) to allow air to escape until water
flows from below the screw head.
Tighten the screw to stop the water from
flowing. Over tightening can cause damage
to the sealing washer and the group cover.
Repeat this procedure for all groups. Once
all air is removed from the coffee boiler,
reinstall the group cover by following the
removal instructions in reverse.
• Steam boiler
Turn the main switch (item 1 in Fig. 1) to
position “1” or ON, the automatic steam
boiler level gauge will be switched on,
activating the auto-fill solenoid valve and
the motor pump. This will fill the steam
Fig. 5
CAUTION
Never remove the filter holder
when water is being delivered.
This operation can be extremely
dangerous since the high
pressure built-up inside the blind
filter would spray out hot and
slightly caustic water, which may
cause severe burns. The Coffee
Boiler contains water at elevated
temperature. Water temperature
over 125°F / 52°C can cause
severe burns instantly or death
from scalding.
IMPORTANT
To improve the flavor of the espresso, the
temperature of the water in the coffee boiler
and therefore of the groups may eventually
be raised or lowered via the digital display
(please consult the Software Programming
Manual for detailed instructions).
WARNING
The machine must not be dipped
in, nor splashed with, water in
order to clean it. For cleaning
operations, please follow the
instructions listed below very
carefully.
WARNING
This machine is designed only for
preparing coffee and hot drinks.