MAINTENANCE MANUAL
Speedster
page 25
Check jet in group on scale build-up
Even when you keep your water softener in excellent condition, a minor amount of scale
will still be deposited on the inside of your Speedster. Most ducts within the machine
have such dimensions that a little scale will not influence the brewing process. However,
the flow restrictor, or jet, within the group head has an opening with a diameter of 0.6
mm
2
and is thus most affected by any scale build up. When new, the flow (with filter
holder removed) is 135 ml (+/- 20 ml) in 10 seconds. When this drops to less than 90 ml
in 10 seconds your machine needs attention.
Note!
Opening the group head should be done with extreme care as not to damage any parts.
First, make sure that the decrease in flow is not due to a malfunction of the pump or
expansion valve.
Clean jet in group head
Materials needed
Spanner 11 mm
Allen key 3 mm
Small screwdriver (no. 1)
Figure 15. Showing the jet housing and jet within the group head (left) and an isolated
and exploded view of the jet housing. 3 jets are shown, the middle one is “in position”,
the others show inside and outside of the jet. To avoid damage, do not remove the jet
housing from the group.
Procedure
1.
Disconnect the pump motor (unplug special connector).
2.
Close main tap of water supply.
3.
Make sure that machine is switched “on”.
4.
Put brewing lever in middle position, this will relieve the water pressure in the
coffee boiler and group.
5.
Put brewing lever back in upper position.
2
The coffee water injection system contains 2 jets with 0.6 and 1.5 mm diameter
openings respectively. Normally, the 0.6 mm jet is mounted in the group head.
