REXNOVA ISA 20 BITHERMAL, Installation, Use And Maintenance Manual, Page: 9 / 36

7
FAULT CODES TABLE
To manually reset the system following a fault
condition, press “F” button (Pict.3).
If the operation is successful the boiler will return
to normal operation; if not, the error code
causing the malfunction will be displayed and
technical support will be needed.
IF A FAULT IS NOT SOLVED AFTER
2 MANUAL RESET ATTEMPTS, THE
AUTHORISED AFTER SALES SERVICE
MUST BE CONTACTED.
Pict. 7
Code Possible cause Behaviour Possible actions
E01 Ignition failed Boiler locked
Ensure gas supply valves
before boiler are open
Reset the boiler
Consult technical support
E02
Air pressure switch failure Boiler locked Consult technical support
E03
Heating system temperature
sensor fault
Boiler locked Consult technical support
E04
Domestic hot water system
temperature sensor fault
DHW supplied in provisional
mode
Heating functions normally
Consult technical support
E05 Gas regulation valve fault
Operation at reduced
power
Consult technical support
E08
Central heating system
pressure too low
Boiler locked
Check for leaks in CH
system
Restore sufficient water
pressure to CH system
Consult technical support
E09
Central heating system
water temperature too high
Boiler locked
Reset the boiler
Consult technical support
E13 Electronic board error Boiler locked Consult technical support
E70
Low tension to electronic
board
Boiler locked Consult technical support
E71
Missing circulation in
CH circuit
Boiler locked
Possibile arresto del
circolatore
E99
Parameter configuration error
Boiler locked
Check and reconfigure
the parameters