USER MANUAL
– check condition
Slim Jim User manual
page 27
Check pressure gauges
1.
No pressure: when not brewing, the needles on all gauges should be in “resting position”
(indicating close to 0 bar).
2. Identical pressure: with a blind filter in all groups, all groups active and all pre-infusion cylinders
completely full, all gauges should display identical pressures. A small deviation between the
different gauges (0.2 bar) is within specifications.
Note!
There is no need to replace a faulty gauge immediately. The gauges give feed-back on, but have no
active part in, the brew-process. A machine remains fully operational with faulty gauges as long as
they do not leak. Have a faulty gauge replaced during the next scheduled service.
Opening pressure of expansion valve
You can check the opening pressure of the expansion valve by first having a long flush (about 20
seconds) then quickly locking in a blind filter and activating the group again. After filling of the pre-
infusion cylinder, pressure will quickly rise to pump pressure and then the expansion due to heating up
the cold inflow of water will increase the pressure inside the coffee system above pump-pressure. The
gauge should reach a maximum value between 10.5 bar and 13.5 bar and then remain constant.
Notes!
-
If the pressure rises above 13.5 bar, the expansion valve opens at too high pressure.
-
If the pressure does not rise over 10.5 bar it is possible that (1) the expansion valve opens at too
low pressure or (2) the one-way valve in the system is malfunctioning or (3) the group-valve starts
leaking at too low pressure.
When the above is encountered, have a technician solve the problem as soon as possible.
Consistency in programmed volumes
Programmed volumes mutate during a few days after installation as during first fill there will be an
inflow of about 0.8 litres in the heat exchanger plus another 0.8 litres of fresh water to each group.
After a few days air content in the coffee-water is stabilised.
Before programming volumes with the Bastones or touchpads the machine must be completely
warmed up and used to make coffee a few times per group. Using the machine ensures that the drain
contains some water (which may evaporate overnight when the machine is not used but still warm).
Variance in coffee bed characteristics (ground coffee particle size and distribution and packing/
tamping) should be as small as possible. For that reason you have to make sure that the coffee-bed
during volume-programming is the same as during normal coffee preparation. Do not use ground
coffee that has been in a storage container if you normally use grinding-on-demand; level and tamp
the coffee-bed as if to make an actual brew; etc..
Flow rate during the entire brew should not fall below a certain minimum. When the flow at any time
during the brew becomes slower than 25 ml/minute (0.7mm flow meter) or 20 ml/minute (1.15mm flow
meter with 4 magnets) flow will come to a (near) stand-still and may not properly drive the impeller.
When an LED on a Bastone or touchpad starts blinking during the brew (and the corresponding area
on the interface shows error message
“flow m.”, see page 13) it is certain that the flow is too slow but
the blinking (and error message) may hold off even when flow was too slow for accurate counting.
When you prefer to brew real slowly, we advise to use scales under the cup in combination with
manually (de-) activating the group for best weight consistency in the cup.
