Astoria 1GR Use And Maintenance Manual page 17

2.9.7 LEVER group
The group lever uses the heating unit pressure and water. This
system does not require heat exchangers.
When the lever (1) is lowered, the spring (2) inside the group
is compressed: the piston (3) raises, allowing the water to en-
ter the pre-infusion jacket.
When the lever is released, the piston compresses the water
at 8-10 bar, allowing the espresso coffee to be dispensed.
The check ball valve (4) prevents the water from flowing back
into the heating unit (5).
5 4
PHASE 1
Lowering the Pre-infusion for
lever 3-5 seconds
TECHNICIANS' manual
1
PHASE 2 PHASE 3
The lever releases
and coffee is dis-
pensed.
2.9.8 Group with an EXTRACTABLE
exchanger
The dispensing group heating is provided by direct contact
with the heating unit. The water used to dispense coffee is
taken from a so-called "extractable" exchanger which is im-
mersed in the heating unit's water:
• When the solenoid valve and pump activate, this allows
cold water to enter into the exchanger (1).
• The heating unit water is carried from the exchanger (1)
to the group (2) for dispensing.
• The pump allows the water flow pressure to increase to
0.8-0.9 MPa (8-9 bar).
The version of the extractable exchanger for the Italian mar-
ket does not include the suction hose (3) and seal (4).
If necessary, the exchanger can be replaced without having
to remove the flange: loosen the screws, remove the dispens-
ing group from the heating unit and remove the exchanger.
These operations should be carried out when the machine
2
has been switched off and has cooled down: always replace
the seals.
3
1
Water
inlet
4
Dispensing
coffee
2
19
2
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