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Table of error codes
If the system shuts down, a code will appear on the system interface
display signalling the type of shutdown and the reason behind it.
To restore normal operation, follow the instructions provided on the
display or, if the error persists, contact an authorised Technical Service
Centre for assistance.
ERROR
DESCRIPTION
1
14
Faulty outdoor sensor
4
20*
Bus power supply overload
9
02
Faulty primary delivery sensor
9
03
Faulty primary return sensor
9
10
Error in communication with HP (RS 485)
9
21
Error Electricity/Gas Cost ratio
9
24
Error in communication with HP (e-BUS 2)
9
25
No boiler
9
33
Primary circuit overtemperature (>90°C)
9
34
faulty storage cylinder sensor (NIMBUS FLEX)
9
35
storage cylinder overtemperature (NIMBUS FLEX)
(>85°C)
9
36
Under-fl oor heating thermostat error (ST1)
9
37
Water circulation error
9
38
Anode error (NIMBUS FLEX)
9
39
Heat pump error **
9
40
Defi ne hydraulic circuit diagram
9
45
fl ow switch stuck
9
46
HP compressor error
2
P2
Sanitation cycle not completed
2
P7
Pre-circulation error
2
P8
HP T° outside operating range
(**) Error codes table (external unit PAC)
In the event of an error on the external unit (PAC error code 939),
access parameter
17.10.1
and refer to the following table to identify
the cause of the error.
ERROR (param-
eter 17.10.1)
DESCRIPTION
2
External alarm signal
3
Water inlet temperature sensor (EWT)
4
Refrigerant temperature sensor (TR)
5
Air temperature sensor GMC
6
Loss of communication with control NUI
7
Room temperature sensor control NUI
9
Water/water pump sensor error
10
Corrupt EEProm
11
Incorrect capacity setting
12
Four-way valve faulty
13
RS485 communication loss (system confi gura-
tion type 6)
14
Loss of inverter board or compressor tempera-
ture sensor signal
15
Water outlet temperature sensor (EWT)
16
Alarm test
17
Inverter air temperature sensor (TO)
18
Inverter short-circuit protection G-Tr
20
Rotor compressor position control error
21
Inverter current sensor error
22
Exchanger refrigerant or compressor intake sen-
sors (TE)/(TS)
23
Compressor delivery temperature sensor (TD)
24
Fan motor fault
26
Other inverter board errors
27
Compressor blocked
28
Delivery temperature sensor error
29
Compressor failure
(*) BUS power supply overload
A BUS power supply overload error may occur due to the connection
of three or more devices within the installed system. Devices which
may overload the BUS network include:
- Multizone
module
- Solar pump unit
- Module for instant production of domestic hot water
To avoid overloading the BUS power supply, set microswitch 1 on one
of the P.C.B.s inside the equipment connected to the system (except
the boiler) to OFF, as illustrated in the fi gure.
1
ON
OFF
2
microswitch