La Marzoco GS/3 Owner's Manual - page 8
Adjusting the Expansion Valve. The expansion valve
is a component that limits the maximum pressure in the
coffee boiler. Heating the coffee boiler causes the water
within to expand. Since the coffee boiler is completly
saturated, the expanding water causes an increase in
pressure within the boiler. Without a safety device the
increase in pressure could cause a rupture in the boiler.
The pressure in the coffee boiler should never exceed
12 bar. To increase pressure rotate the expansion valve
clockwise. To decrease pressure rotate the expansion
valve counter clockwise (See the following diagram).
Adjusting Water Pump Pressure. The water pump is
factory set at 9 bar pressure. If it becomes necessary
to change the pressure please use the following
procedure:
1. Remove the left side cover assembly.
2. Locate the water pump adjustment screw and
loosen the lock nut.
3. Adjust the water pump pressure to the desired
measurement.
4. Rotate Clockwise to increase pressure and
counter clockwise to reduce pressure.
8.
9.
Water Pump
Pressure Adjustment
Screw
Left Side Panel
Assembly
Adjustment
Screw
Lock Nut
Figure 7 - Water Pump pressure Adjustment
Increase
Pressure
Decrease
Pressure
Figure 6 - Expansion Valve Adjustment
NOTE: The water pump pressure should be
adjusted when the machine is operating and coffee
is present in the portafi lter.
WARNING
!
!
The expansion valve can discharge water as hot as
200°F / 93°C. Adequate protection for handling this
component is needed before atempting to adjust.
English
7
La Marzocco, S.r.l. Firenze, Italia
Installation
Version 1.00