USER MANUAL
– check condition
Slim Jim User manual
page 26
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 maintenance.
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 of 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) a group-valve from
another group starts leaking at too low pressure.
When the above is encountered, have a technician solve the problem as soon as possible.
External temperature probe (option)
If you have this option, connect the external probe to the machine and set the interface to show its
temperature (see page 13) to check individual temperatures of brews and/or hot water.
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 the excess air, which is always present in tap water, has segregated and will be
expelled from each group and 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
trap 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 grinds that
have been in a storage container if you normally use grinding-on-demand; level and tamp the grinds
as if to make an actual brew; etc..
Flow rate during the entire brew may not fall outside the range of the flow meter: the maximum flow-
rate cannot be exceeded due to machine set-up but the flow-rate during a shot 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 35 ml/minute (1.15mm flow meter) the impeller in the flow meter will come to a
(near) stand-still. When an LED on a bastone or touchpad starts flashing during the brew (and the
corresponding area
on the interface shows “flow m.” (see Figure 20) it is certain that the flow is too
slow but the blinking may hold off even when flow was too slow for accurate counting. The error
message will disappear the next time the group is activated.