Riello NXC 021 - Alarm Codes and Management; Alarm Menu and LED Indicators; Alarm Reset Procedures

Alarm codes
98
EN
Alarm
number
Alarm code Alarm description Reset mode Probable cause Control system reaction
Thermistor faults
19 Co-o2 CommunicationlosswithPD-AUX2board As above As above None
Process faults
20 P-01 Anti-freezeprotectionofthewater-
refrigerantexchangerhasbeentriggered
Automatic if the alarm has not
beentriggeredintheprevious
24hours,otherwisemanual
Waterowratetoolow
or thermistor fault
Unit stop
21 P-05 LowsuctionpressureofcircuitA Automaticwhenthedetected
pressureisbacktonormal
andthealarmhasnotbeen
triggeredintheprevious24
hours,otherwisemanual
EXVvalvelockout,
sensorfaultorlow
refrigerant charge
Stop of the circuit
22 P-06 LowsuctionpressureofcircuitB As above As above As above
23 P-08 High overheating of circuit A As above As above As above
24 P-09 High overheating of circuit B As above As above As above
25 P-11 LowoverheatingofcircuitA As above As above As above
26 P-12 LowoverheatingofcircuitB As above As above As above
27 P-14 Flowratecontrolinterlockfaultorexternal
safetydevicefault
Automatic if the unit is in
manual stop, manual in all
other cases
Refrigerant/water
exchangerpumpfault
ornoow
Unit stop
28 P-16 Compressor A1 not starting or pressure
increase failure
Manual Connection problems Compressor stop
29 P-17 Compressor A2 not starting or pressure
increase failure
As above As above As above
30 P-18 Compressor A3 not starting or pressure
increase failure
As above As above As above
31 P-20 Compressor B1 not starting or pressure
increase failure
As above As above As above
32 P-21 Compressor B2 not starting or pressure
increase failure
As above As above As above
33 P-29 SystemManagercommunicationloss Automaticorresetbythe
communications
Bus installation error of
CCNnetwork
The device switches to stand-
aloneoperatingmode
34 P-30 CommunicationlossbetweenMasterand
Slave
Automaticorresetbythe
communications
Bus installation error of
CCNnetwork
As above
35 MC-nn CongurationerrorofMasterchillerNo.1 Automatic upon restoring
correctcongurationor
upon stopping Master / Slave
operationmode
Master/Slave operation
congurationerror
Stop of the Master/Slave operating
mode
36 FC-n0 Nofactoryconguration Automatic upon entering
factoryconguration
Unitsizehasnotbeen
congured
Unit stop
37 FC-01 Illegalfactorycongurationnumber Manual Unitsizehasnotbeen
correctlycongured
As above
38 P-31 EmergencystopfromCCNnetwork Manual CommandfromCCN
network
As above
39 P-32 FaultofpumpNo.1forwatercirculation Manual Pump motor
overheating or pump
connection missing
Stop of device operation with no
emergencypump
40 P-33 FaultofpumpNo.2forwatercirculation Manual As above As above
41 P-37 RepeatedcapacitycontrolsofcircuitAfor
highdeliverypressure
Automatic Transducerfaultor
cooling circuit problems
None
42 P-38 RepeatedcapacitycontrolsofcircuitBfor
highdeliverypressure
Automatic As above As above
43 P-40 RepeatedcapacitycontrolsofcircuitAforlow
suction pressure
Manual Transducerfaultor
refrigerant charge
missing
Circuit operation stop
44 P-41 RepeatedcapacitycontrolsofcircuitBfor
lowsuctionpressure
Manual As above As above
45 P-43 Heatexchangertemperaturetoolow(less
than10°C)preventingstart-up
Automaticafterdetected
temperatureisbacktonormal
orwhentheunitworksin
coolingmodeagain
Protection of out-of-
rangecompressorand
temperature sensor
fault
Thedevicecouldnotbestarted
46 P-97 Inversionofentering/leavingwater
temperature sensors
Manual Faultysensor.Sensor
inversion
Unit stop
48 V0-xx Faultofvariableowrateregulatorofcircuit
A
Manual or automatic Faultorwarningfor
speedregulator
Warning: the circuit carries on
workingbuttheregulatorslows
downthemotor
alarm: the circuit stops