Immergas NIKE MINI 28 KW SPECIAL, Instruction And Warning Booklet

Page: 15 / 24

15
4
3
2
1
5
6
INS
TALLER
US
ER
MAINTEN
AN
CE TECHNI
CI
AN
3.4 CONVERTING THE BOILER TO
OTHER TYPES OF GAS.
If the appliance needs to be converted to a
different gas type to that specified on the data
plate, request the relative conversion kit for quick
and easy conversion.
Boiler conversion must be carried out by a
qualified technician (e.g. Immergas After-Sales
Technical Assistance Service).
To convert to another type of gas the following
operations are required:
- disconnect the appliance;
- replace the main burner injectors, making sure
to insert the special seal rings supplied in the
kit, between the gas manifold and the injectors;
- move jumper 16 (Fig. 3-3) to the correct
position for the type of gas in use (Methane or
L.P.G.);
- to access adjustments on the circuit board, the
cover must be removed from the dashboard by
taking out the rear fixing screws;
- re-power the appliance;
- adjust the maximum heat power of the boiler;
- adjust the minimum heat power of the boiler;
- adjust (if necessary) the heating power;
- seal the gas flow rate regulation devices (if
settings are modified);
- after completing the conversion, apply the
sticker, contained in the conversion kit, near
the data-plate. Using an indelible marker pen,
cancel the data relative to the old type of gas.
These adjustments must be made based on
the type of gas used, following the indications
provided in the tables (Par. 3.16).
3.5 CHECKS FOLLOWING CONVERSION
TO ANOTHER TYPE OF GAS.
After making sure that conversion was carried
out with a nozzle of suitable diameter for the
type of gas used and the settings are made at the
correct pressure, check that:
- there is no flame in the combustion chamber;
- the burner flame is not too high or low and that
it is stable (does not detach from burner);
- the pressure testers used for calibration are
perfectly closed and there are no leaks from
the gas circuit.
N.B.: All boiler adjustment operations must
be carried out by a qualified technician (e.g.
Immergas After-Sales Technical Assistance
Service).
Burner adjustment must be carried out using a
"U" or digital pressure gauge connected to the
gas valve outlet pressure point (Part. 4 Fig. 3-3),
keeping to the pressure value provided in the
tables (Par. 3.16) according to the type of gas for
which the boiler is prepared.
Fig. 3-3
P.C.B. SIT 845 GAS Valve
10 - Phase fuse 3.15AF
11 - Neutral fuse 3.15AF
12 - Main switch
13 - Domestic hot water temperature trimmer
14 - RS232 computer interface
15 - Central heating temperature trimmer
16 - METHANE L.P.G. gas type selector
3.6 POSSIBLE ADJUSTMENTS OF THE
GAS VALVE.
• Adjustment of boiler nominal heat output (see
previous figure).
- Turn the domestic hot water temperature
selector (10 Fig. 2-1) to maximum;
- open the domestic hot water cock in order to
prevent modulation from starting up;
- adjust the nominal boiler power from the brass
nut (3), keeping to the maximum pressure
values provided in the tables (Par. 3.16)
depending on the type of gas;
- by turning it clockwise the heating potential
increases and by turning it anti-clockwise the
heating potential decreases.
• Adjustment of minimum boiler heat output
(Fig. 3-3).
N.B.: only proceed after having calibrated the
nominal pressure.
Adjustment of the minimum thermal input is
obtained by operating on the cross plastic screws
(2) on the gas valve maintaining the brass nut
blocked (3);
- disconnect the power supply to the modulating
coil (just disconnect a faston); by turning the
screw in a clockwise direction, the pressure
increases, and counter-clockwise it decreases.
On completion of calibration, re-apply the
power supply to the modulating coil. The
minimum boiler power must not be adjusted
to a pressure value below the levels stated in the
tables (Par. 3.16) depending on the type of gas.
N.B.:
to adjust the gas valve, remove the plastic
cap (6); after the adjustment, put the cap back on.
Key:
1 - Coil
2 - Minimum power adjustment screw
3 - Maximum power adjustment nut
4 - Gas valve outlet pressure point
5 - Gas valve inlet pressure point
6 - Protection hood