39
4.1 -
BLANK DISPLAY
In case of blank display, check if the ter-
minals 19 and 20 of the terminal strip (fig.
16) are 230V powered. In case of no pow-
er, check if the fuse is intact. Check then
if the switch On/Off is set to ON. At any
short circuit of the pump (or 3-way valve),
4.2 - THE BOILER DOES
NOT FULFILL THE DHW
PRODUCTION
REQUEST
replace the 2 AF fuse. Moreover check if
the display flat cable is properly connect-
ed to the MBD (the main PCB) and the
display. Should the problem persist de-
spite that the fuse and the power supply
are OK, the MBD needs changing.
WARNING:THE FUSE IS INTO THE 230
V CIRCUIT. MAKE SURE THAT THE
POWER IS OFF BEFORE CHECKING.
4
ERRORS
The boiler does not fulfil the heat request
for the heating system: check if all elec-
trical connections of the room ther-
mostat (on terminals 5-6 of the 20-pole
terminal strip) and, if necessary, of the
outer sensor (on terminals 3-4 of the
20-pole terminal strip) or of the outer
compensator (on terminals 1-2 of the
20-pole terminal strip) have been per-
formed properly; check if there are
any cut cables (see fig. 16).
Check the storage tank NTC sensor and
its wiring.
Check the 3-way valve and its wiring.
Check the storage tank loading pump and
its wiring.
Check all programming parameters.
4.3 - DIAGNOSTICS CVI
ELECTRONIC CARD
In case of failure, the LED ‘’A’’ will be con-
tinuously lighted. Every 10 seconds
the light will be interrupted by a blinking
code reporting the failure reason. The se-
quence here reported will be repeated
up to the reset.
Sequence
4.4 - BURNER LOCKOUTS
A burner lockout is detected by the num-
bers of the thermal element the error re-
fers to, followed by a blinking spot. The
three following digits indicate the error
for 10 seconds for 0,6 seconds
for 1,2 seconds
Light
period
OFF
period
OFF
period
Blinking
code
Blinking
code
Error code
Possible fault
Within safety time,
flame not detected
Lock out within
safety time
the ionisation electrode
could be faulty
False light during
the detection period
Time out air pressure
switch
The air pressure switch
doesn’t close the contact
within the required time
Air pressure switch
in open position
The air pressure switch
doesn’t open during the
ignition or the operation
Leak of flame
Leak of flame during
the operation
Description
= Short blink
= Long blink
Air pressure switch in
close position
Air pressure switch with
attached close contact
nature. See the tables 4.5.1 to 4.5.4 to
know the meaning of all error codes. The
errors that do not refer to a single thermal
element but to the boiler as a whole are
presented by the error number E, fol-
lowed by two digits.
Warning! To reset the boiler, press
both the reset button of each burner
and the reset key.
Fig. 21
A
