La Marzocco Strada Mode d’emploi
La Marzocco Espresso Machines Guideline
The La Marzocco espresso coffee machines work by forcing hot water under high pressure
through finely ground coffee held in a portafilter. The brewing process uses several key
components to accomplish this process.
Nearly every other espresso machine manufacturer uses a single boiler and heat exchanger
located inside the steam boiler. Water for brewing espresso is solely dependent on the
temperature of the single steam boiler and this creates inconsistent brewing and steaming
conditions, thus producing inconsistent drinks.
The La Marzocco espresso machine uses a unique two-boiler systems to isolate and perform
operations in the best possible conditions.
The rear boiler is dedicated to the steam and hot or tea water functions.
The front boiler has the sole purpose of providing brewing water at the correct temperature
and pressure for the coffee the barista is going to brew.
These temperature and pressure parameters are adjustable independently of any other
function of the espresso machine. They are also consistent though most any level of operation.
HOW DOES IT WORK?
Cold, filtered water enters the brewing boiler through a pump which raises the water pressure
to 9 bars to allow the water to flow through the finely ground coffee.
Then the water in the boiler is heated by a heating element, which is controlled by a
Temperature probe connected to a CPU which control and sends power to the element when
the water temperature is low and shuts off power to the element when the water is at
operating temperature.
This means the temperature of the coffee brewing water can be set precisely depending on the
operator's taste, the roast or blend of the coffee used.
When the barista puts the portafilter into the brewing group, it forms a watertight seal
between the portafilter and the group gasket.
When the user presses the brew switch, a solenoid valve opens and the pump generates
pressure to force the hot water from the boiler through the group and the diffusion screen and
screw, then into and through the ground coffee, producing the desired volume of espresso,
which is brewed into heated cups or shot glasses.
On automatic (AV) models, the water is measured by a flowmeter.
The flowmeter sends a signal to the microprocessor as the water flows; when the programmed
amount of water is reached, the microprocessor turns off the solenoid valve and pump,
releasing the pressure against the portafilter.
Since the La Marzocco is built to a different principal than other espresso machines, let’s look
at the individual systems that make up the entire machine.
1. BOILERS
There are two stainless steel boilers that work independently to provide steam and hot water
or hot water for brewing espresso.
The rear boiler provides steam pressure and the front boiler provides hot water for brewing
espresso.
The rear boiler operates partially filled and above boiling.
The front boiler operates completely full and just below boiling.
2. GROUPS
The groups are the actual brewing chambers that house the coffee to be brewed.
The La Marzocco uses a hollow stainless steel group welded directly on the stainless steel
boiler.
It is critical to prevent the machine or group from cooling down.
Hot water is constantly circulating in the group any time the machine is hot.
This allows the group to maintain the correct brewing temperatures at all times.
Once the dispense button is depressed, hot water that has been circulating though the group is
released by means of a solenoid valve.
Water flows from the left side of the group (as you are facing it) to the flowmeter (AV models)
or to directly to the solenoid valve (EE models).
The water then travels back into the group on the right side and through a tube before it is
dispersed onto the fresh coffee grounds.
3. GROUP VALVES
Each group has a solenoid valve mounted underneath to allow water to flow through the group.
Group valves are three way valves that allow water to flow in a specific direction and that
direct any back pressure to be discharged into the drain box.
Each valve consists of a housing or body, which contains the valve seat, and a piston, that
travels within a valve stem.
The piston is spring loaded to create a seal when the valve is at rest.
The valve is opened with a coil that creates a magnetic charge and draws the piston away from
the valve seat and is closed with spring pressure.
4. FLOWMETER
The flowmeter measures the volume of water passing through the groups.
The flowmeter consists of an impeller or wheel that contains two small magnets, and a body or
housing that contains a precision orifice or jet that controls the amount of water that can flow
into the flowmeter.
When water enters the flowmeter, the impeller spins and the magnets pass under the
electromagnetic field.
Each time a switch in the field closes a pulse is sent to the microprocessor to be counted.
5. AUTOFILL SYSTEM
The autofill system maintains the water level in the rear or steam boiler.
The autofill system consists of a sensor or probe, and a two-way solenoid valve.
The sensor is a metal probe that is insulated from surrounding metal with a teflon seal and is
inserted into the boiler.
The microprocessor reads this post though a lead or wire.
The microprocessor is programmed to detect a ground or earth signal from this sensor.
If it does not, it opens the two way solenoid valve and allows water to fill the boiler.
When the water level reaches the metal post the microprocessor can detect the ground or
earth signal and closes the two way solenoid valve.
6. VACUUM VALVE
The vacuum valve avoids the steam to escape from the boiler until sufficient steam pressure
develops to lift the cone and seal the boiler.
This valve prevents a false pressure reading when a machine is initially heating: as hot as it
heats, the water expands.
The pressure switch cannot detect the difference between air pressure or steam pressure.
By allowing the air pressure that develops from the expanding water to escape, a true steam
pressure can build as the machine continues to heat.
This valve also reduces any possibility of contaminating the steam boiler (milk suction through
the vacuum effect caused by the steam pressure decrease).
7. EXPANSION VALVE
The expansion valve relieves front boiler pressure at about 12 bar.
The expansion valve is located in the drain box, which is underneath the drip tray.
The expansion valve consists of a valve body or housing, a valve seal and spring which are
enclosed in an adjustable, and a brass barrel.
The expansion valve is adjusted by increasing or decreasing pressure on the spring by turning
the brass barrel.
It should begin to drip at 10-11 bar and release fully above 12 bar.
8. SAFETY RELIEF VALVE
The safety relief valve relieves boiler pressure at 1.8 bar thus preventing the steam boiler from
over-pressurizing. It is factory adjusted and sealed. It cannot be adjusted.
9. MOTOR PUMP
The motor pump increases existing water pressure to 135psi or 9 bar.
This is the optimum pressure for brewing espresso.
An adjustment screw is located on the side of the pump inside the cap screw.
Some pumps have accessible screws and some pumps have a cap screw that must be removed
to make an adjustment.
Turning the screw clockwise will increase the pump pressure and counter clockwise will
decrease pressure. Make pump pressure adjustments while simultaneously brewing espresso.
Check that your water supply pressure is stable before making an adjustment.
A fluctuating water supply pressure will affect the final result. If your water pressure does
fluctuate it is required to install a water pressure regulator or floating bypass rotating pump.
10. MAIN POWER SWITCH
Power enters the machine through the power cord, which then enters a large terminal block,
and then to the main power switch.
The main power switch has three positions:
“0” This is the “off” position
“1” This is the “fill” position. It activates all systems except the heating elements.
“2” This is the “run” position. It provides power to all systems. (JUST ON LINEA AND FB/70)
11. THERMOSTAT (ON THE LINEA AND FB/70)
The thermostat controls the temperature of the front boiler.
The thermostat resides in a well that isolates it from the water but allows the temperature of
the water to transfer.
The thermostat contains a bellows filled with a thermal fluid that expands and contracts
depending on the surrounding temperature.
As the water heats in the coffee boiler it causes the fluid in the bellows to expand, which
drives a piston up.
When the piston rises, it eventually activates a switch, which turns off the heating elements.
As the water cools the piston will fall and allow the switch to turn on again and repeat the
heating cycle.
The thermostat contains an adjustment screw that adjusts the distance the piston must travel
to activate the switch, thus adjusting the temperature.
To increase temperature turn the screw clockwise; to decrease turn counterclockwise.
Each 1/4 turn of the adjustment screw represents approximately 2 degree Celsius temperature
change.
12. HEATING ELEMENT
Each boiler has independently operated heating elements.
The element for the steam boiler receives electrical power from the pressure switch.
The elements for the coffee boiler receive electrical power from the thermostat.
As electrical power is applied to the element it heats the surrounding water in the boiler.
13. CONTROL BOX
The control box is the most complicated component in the machine. It can be divided into the
following systems:
1) Power supply: Converts high voltage AC into 18 volts DC (to power the relays) and 5
volts DC (to power the microprocessor and logic circuits).
2) Autofill system: This circuit monitors the signal from the autofill sensor and determines if
it has established a ground.
3) Input system: These are the ribbon cables that carry information between the menu button
pads and the control box.
4) High voltage output: This provides power to the coils and pump motor when the
machine is called to brew espresso, fill the steam boiler or dispense hot water for brewing
espresso.
5) Power supply: This consists of a transformer, and a40mA fuse. The fuse protects
the components in the event that something has failed or shorted in the DC system.
The transformer is the cube on the board. Its purpose is to reduce the high AC voltage to 18
volts AC. with the help of a series of diodes it is converted to DC voltage.
14. PRESSURE SWITCH
The micro pressure switch controls the steam pressure in the rear boiler by activating a
contactor which supplies power to the heating elements.
When the steam pressure lowers in the boiler (usually 1.1 or 1.2 bar) the contacts close
allowing power to flow from the bottom leads through the top leads and then to the heating
element.
As the steam pressure builds and reaches 1.5 bar the micro switch cuts the power to the
heating elements.
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La Marzocco
La Marzocco
Machines Basic Guideline
Machines Basic Guideline
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What should I do to maintain my
espresso machine?
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1. Clean the group heads daily.
A. Gently remove the basket
from the portafilter, using a
small flathead screwdriver.
Complete this maintenance
sequence daily for each
group and portafilter.
B . Remove basket.
Place portafilters and baskets
in a PuroCaff solution
(1 spoon every 1/2 liters).
Leave to soak for ten to fifteen
minutes.
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C. Install a blind insert into the portafilter.
Pour PuroCaff (1 teaspoon) into the blind
filter and install the portafilter into the group.
D. Cycle the group on and off.
Run for thirty seconds, then turn off for ten seconds.
Repeat by turning on for five seconds and off for five
seconds, for ten iterations.
Then remove portafilter and dump dissolved coffee
oils and residue into the drain tray.
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E. Rinse blind filter under group
head until water flows clear.
F. Clean remaining coffee grounds
from the portafilter engagement
area with a cleaning brush.
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G. To remove residual detergent, install
portafilter with an empty blind insert into the
group and flush for five seconds.
Repeat ten times.
H. Re-season the group by brewing and
discarding few shots of espresso.
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I. Now remove baskets and inserts
from the PuroCaff solution and rinse
thoroughly.
L. Verify that the basket
spring is seated in position.
Reassemble portafilters and
install at each group.
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2. Clean the diffuser screens and groupheads daily.
A. Remove the portafilter from
the group.
Loosen the diffuser screw using a
stubby flathead screwdriver.
Remove the diffuser screw and
screen assembly.
B. Mix a solution of PuroCaff.
(ONE table-spoon of PuroCaff
per 1/12 liter of hot water.)
Place the diffuser screen and
screw into the PuroCaff solution.
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Ce manuel convient aux modèles suivants
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Table des matières
Autres manuels La Marzocco Cafetière
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La Marzocco GS/3 Manuel utilisateur
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La Marzocco MICRA Manuel utilisateur
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La Marzocco SWIFT EPSB Manuel de programmation
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La Marzocco Linea Manuel utilisateur
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La Marzocco GB/5 Manuel de service
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La Marzocco linea mini Manuel utilisateur
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La Marzocco GB/5 Manuel de service
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La Marzocco GS/3 Manuel utilisateur
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La Marzocco GS/3 Manuel utilisateur
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La Marzocco Strada AV Manuel utilisateur
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La Marzocco GS/3 Manuel utilisateur
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La Marzocco linea mini Manuel utilisateur
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La Marzocco GB/5 Manuel du propriétaire
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La Marzocco Linea Classic Feuille d'instructions
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La Marzocco strada ep Manuel utilisateur
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La Marzocco FB 70 Manuel utilisateur
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La Marzocco SWIFT EPSB Manuel utilisateur
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La Marzocco Linea PB Manuel utilisateur
La Marzocco
La Marzocco STRADA MP Guide d'installation
La Marzocco
La Marzocco Strada AV Manuel utilisateur
