Green Heating Technology
38
f
afterwards, in case of
MANUal
calibration, the CO
2
values can be adjusted:
•
select one of the phases
LO
,
ME
or
HI
by the buttons
and
and wait for the stabiliza
-
tion of the CO
2
value on the analyser;
• adjust the CO
2
value, if necessary, by the buttons
and
;
• proceed in the same way for the other two phases (eventually exclude the
ME
).
f
Store the set by keeping the button
pressed for at least 2 seconds.
f
If the value of the Parameter 49 has been modified to carry out the AUTO calibration, restore it to
factory setting (see page 34).
Accessing the main board
The main PCB has no hardware adjustment devic
-
es onboard, so no access to it is required, except in
case of cabling check or replacement of the board
itself. Proceed as follows:
Cut off the electrical supply to the boiler.
Restore the supply after having closed the
control panel rear cover�
f
unscrew the screws
1
and release the latches
2
;
f
remove the back cover of the control panel�
An incorrect or not complete closure of the electronic box voids the IP grade of protection of
the appliance.
Ensure that all closing items are correctly used and that all cables pass through
the suitable slots. If one or more latches
2
should break, please use holes
3
with suitable screws
(similar to the standard ones
1
).
Main board replacement
Carefully follow the instructions included in the spare board kit.
Board
configuration
codes
Model
Gas G20 (1)
Conv. to G31 (2)
City Class 25 K
30170
31170
City Class 30 K
30270
31270
City Class 35 K
30370
31370
(1)
Factory preset; code written on the sticker on the electronic box
(2)
Code that will appear on the display (for some seconds at the moment of the electrical supply)
if the Parameter 01 has been changed because of gas conversion.