Wega Mininova, Instructions Manual

Page: 92 / 126

90
espresso coffee machine - technician instructions
English
Indication
Cause Solution
COFFEE IS TOO COLD
1) The electrical heating element is defective
2) The electrical connection is defective
3) Lime scale on heat exchanger and/or heating element
4) The pressure switch contacts are oxidized
5) The heating element protection thermostat has cut in
6) Lime scale has reduced the circulation of water
7) The delivery group is cold
1) Replace the electrical heating element
2) Check for any defective connections
3) Clean the machine
4) Clean the contacts or replace the pressure switch
5) Reset the heating element protection
6) Clean the connections of the exchanger, and clean or replace
the two circulation tubes
7) Eliminate air pockets in the hydraulic circuit in the following
manner:
- disconnect the electrical power supply to the pump
- close the mains water tap
- perform a dry delivery run for a few minutes
- reconnect the electrical power supply to the pump
- open the mains water tap
- perform delivery until water comes out
- wait a few minutes for heating
COFFEE IS TOO HOT
1) The boiler temperature is too high
2) The flow reducer of the group is unsuitable
1) educe pressure in the boiler by turning the appropriate screw
on the pressure switch (versions EMA-EPU)
2) Replace the injector with one of a smaller diameter
COFFEE DISPENSED
TOO QUICKLY
1) The coffee is ground too coarsely 1) Adjust the grinding of the coffee
COFFEE DISPENSED
TOO SLOWLY
1) The injector is clogged
2) The delivery group is clogged
3) The filter holder is dirty
4) Coffee is ground too finely 1) Replace the injector
2) Check and clean the delivery group
3) Clean and replace the filter holders, if necessary
4) Adjust the grinding of the coffee
COFFEE GROUNDS
ARE WET
1) The group solenoid valve discharge is clogged
2) The delivery group is too cold 1) Clean the group drain
2) Wait for group to heat up completely
THE GAUGE SHOWS AN
UNACCEPTABLE
PRESSURE
1) The pressure gauge is defective
2) Incorrect pressure switch calibration (versions EMA-EPU) 1) Replace the pressure gauge
2) Adjust the calibration of the pressure switch (versions EMA-EPU)
GROUNDS IN CUP
1) The filter holder is dirty
2) The undercup seal is worn 1) Clean the filter holder
2) Replace the seal
for EVD :
INCORRECT
COFFEE DELIVERY
THE COFFEE
DOSE IS NOT MET
THE LED OF THE DOSE
BUTTON FLASHES
1) The connection of the volumetric dosing device
is defective
2) The connection of the electronic control unit
is defective
3) The connector of the volumetric dosing device has humidity
on it
4) The volumetric dosing device is defective: during delivery
the dosing device LED does not flash
5) The non-return valve loses pressure
(the dose is too small)
6) The drain valves lose pressure
(the dose is too small)
7) Water leakage from the group solenoid valve during coffee
delivery or when at rest
8) The volumetric dosing device is partially obstructed 1) Check for proper connection of the volumetric dosing
device connector
2) Check for proper connection of the 8-pin connector of the
electronic control unit
3) Remove the connector of the volumetric dosing device and
thoroughly dry the contacts
4) Replace the heads of the volumetric dosing device or replace
the dosing device
5) Check and replace the non-return valve,
if necessary
6) Check and replace the drain valves,
if necessary
7) Clean and replace the solenoid valve,
if necessary
8) Clean or replace the volumetric dosing device