Gas Adjustments; Changing The; Ype Of - Ariston microCombi 23 MFFI Installation And Servicing Instructions

4.

GAS ADJUSTMENTS

Model CATEGORY II2H3+
23 MFFI
Lower Wobbe Index (15°C;1013mbar)
27 MFFI
Nominal Delivery Pressure
Minimum Delivery Pressure
23 MFFI Main Burner: n. 12 jets (ø)
Consumption (15°C; 1013mbar)
Consumption (15°C; 1013mbar)
Gas Burner Pressure
max - min
27 MFFI Main Burner: n. 13 jets (ø)
Consumption (15°C; 1013mbar)
Consumption (15°C; 1013mbar)
Gas Burner Pressure
max - min
4.1 C
HANGING THE
T G

YPE OF

AS
4.2 A
DJUSTING THE
26
The boiler can be converted to use either methane (natural) gas (G20)
or L.P.G. (G30 - G31) by an Authorised Service Centre.
The operations that must be performed are the following:
1. Replace the jets on the main burner (see table in section 4);
2. Adjust the maximum and minimum thermal capacity values for the boiler
(see table in section 4 and 4.2 Adjusting the Gas Pressures);
3. Adjust the maximum thermal power setting;
4. Adjust the soft-light feature (see table below for recommended
pressure);
5. Adjust the ignition delay feature for the heating system by adjusting the
potentiometer as shown in F
CATEGORY
II2H3+
Recommended
Soft-light
Pressure
(mbar)
G P (S
AS RESSURES IT
Setting the minimum and the maximum power of the boiler
1. Check that the supply pressure and dynamic pressure to the gas valve is
a minimum of 20 mbar for natural gas.
2. To do this, loosen the screw "A".
Fit the pipe of the pressure gauge to the inlet pressure connection of the
gas valve "B" and check for the correct standing pressure, then operate
the appliance and check for the correct working pressure.
When you have completed this operation, replace the screw "A" securely
into its housing to seal off the gas (check for tightness).
3. To check the pressure supplied by the gas valve to the burner, loosen the
screw "C". Fit the pipe of the pressure gauge to the pressure outlet test
Methane Gas
G20
MJ/m 3 h 45.67
mbar 20
mbar 20
mm 1.30
m 3 /h 2.78
Kg/h ----
mbar 11.0 - 2.0
mm 1.3
m 3 /h 3.10 - 1.16
Kg/h ---
mbar 12.2 - 1.7
Model
Microcombi
23 MFFI
27 MFFI
S )
IGMA
Liquid Butane Gas Liquid Propane Gas
G30
80.58
29
28
0.77
----
2.02
27.7 - 6.0
0.77
---
2.31 - 0.87
27.8 - 5
. 4.1 (can be set from 0 to 2 mins.).
IG
Methane Gas Liquid
Butane Gas
G20
G30
8.0 16.0
6.7 12
G31
80.58
37
36
0.77
----
2.00
35.5 - 7.3
0.77
---
2.27 - 0.85
35.8 - 5.3
Liquid
Propane Gas
G31
16.0
12