HWMC
36
All copying, even partial, of this manual is strictly forbidden
RG66008809 - Rev 00
11 TROUBLESHOOTING
In this section you will find a list of the most common problems that may cause the chiller unit to stop or malfunction. Possible remedies are shown along-
side a description of easily identifiable remedies.
Warning
Extreme care should be taken when performing work or repairs on the unit: overconfidence can result in injuries, even serious ones, to in-
expert individuals. Operations marked with the letter "U" can be performed directly by the user, who must carefully follow the instructions provided in this
manual.
Operations marked with the letter "S" may be performed exclusively by specialised personnel.
Once the cause has been identified, you are advised to contact a Galletti service centre or a qualified technician for help.
SYMPTOM
Cooling
Heating
Who can take
corrective action
U = User
S = specialised
personnel
Possible control panel
indication
Probable cause
Possible remedy
A The unit does
not start
X
X
S
Alarm from Digital Input
Faulty connection or contacts open
Wrong voltage
Check the voltage and close the contacts
X
X
S
Not enabled by remote controls
Check the efficiency of the water circulation
pump, pressure switch, bleed air from the
circuit; check whether contacts 16 and 30 on
the terminal board are closed
X
X
X
X
S
U
Evaporator Inlet Temp.
Sensor Alarm
Service thermostat sensor defective
Not enabled by service thermostat
Check and replace if necessary
System at the set temperature, no demand;
check the setting
X
X
U
Antifreeze Alarm - circuit 1
Not enabled by antifreeze
thermostat
Check the water temperature
Checking the antifreeze setting
X
X
S
Evaporator Inlet Temp.
Sensor Alarm
Antifreeze sensor defective
Check whether it is functioning properly
X
X
S
Tripping of main circuit breaker
Check for the presence of short circuits in
the wiring or windings of the pump, fan and
compressor motors or in the transformer.
X
X
X
X
S
S
LOW pressure alarm
circuit 1
HIGH Pressure Alarm
circuit 1
Not enabled by high or low pressure
switch
Compressor defective
See items D-E
See item B
B The compressor
does not start
X
X
S
Compressor burnout or seizure
Replace the compressor
X
X
S
Compressor contactor deenergized
Check the voltage at either end of the
compressor contactor coil and verify the
continuity of the coil itself
X
X
S
Power circuit open
Locate the cause that tripped the protection;
check for the presence of short circuits in
the wiring or windings of the pump, fan and
compressor motors or in the transformer
X
X
S
Inverter Alarm
Motor thermal protection open
The compressor has operated in critical
conditions or there is insufficient refrigerant
within the circuit: check the working conditions
and make sure they fall within the operating
limits.
Refrigerant leak: refer to item G
X X
U S
User flow alarm
DHW flow alarm
Water circulation pump blocked
Defective water circulation pump
Lack of water flow
Release the pump
Check the pump and replace it if necessary
Let water flow
C The compressor
starts up and
stops repeatedly
X
X
S
LOW Pressure Alarm
triggered by sensor
-circuit 1
Minimum pressure switch has
tripped
See item E
X
X
S
Compressor contactor defective
Check and replace if necessary
X
X
S
Lack of refrigerant
See item G