Excessive rinsing of the portafilters with water from the brew group
will gradually drive down the temperature in the brew boiler. This
lowering of the brew temp will result in espresso shots that are less
than ideal: weak extraction, very little crema, and unusually high
volume.
Use water from the machine’s hot-water tap to rinse portafilters.
Problem 1 - Shot volumes are inconsistent.
Solution 1 - Limit rinsing of the portafilters with water from the brew group.
Solution 2 - Inspect the flowmeter for proper operation.
On automatic models, the flowmeter measures the quantity of water flowing to the brew group.
The flowmeter uses an impeller, imbedded with two magnets, to actuate a hal-effect switch to
send pulse signals to the control box. The control box counts the pulses received from the flow
-
meter to gauge water volume.
Important! - Before proceeding with solution 2, the following steps must be accomplished.
1. Turn off the main water supply to the machine.
2. Locate the expansion valve in the drain box.
3. Turn the barrel of the expansion valve counter-clockwise to relieve pressure in the
front boiler.
4. When the lower portion of the gauge reads 0 bar, you may proceed.
2. Remove the red
and white wires from
the flowmeter field.
Measure DC voltage
from the red wire to
ground, you should
get a reading of 18vdc
+/- 10%.
Any other reading in-
dicates a faulty trans-
former on the control
board.
3. Using a multi-meter, test the flowmeter
field for an electrical short. Place both
leads on the terminals of the field. A func
-
tional flowmeter will result in a reading of
2.2k ohms +/- 10%.
If the ohm reading is not within the proper
range, the field is faulty and should be
replaced.
If the reading is with the proper range,
proceed to step 4.
1. Remove the ma-
chine’s top panel.
