23
3.6. Switching to different gas and burner
adjustment
Boilers are manufactured to be fueled by the gas type whi-
ch was specified upon order
Subsequent transformations are to be performed exclusi-
vely by qualified personnel, employing manufacturer ap-
proved parts, and implementing all the adjustments and
modifications necessary for a correct tune-up.
Adjusting the boiler from methane to LPG
- Remove the main burner
- Remove main burner nozzles from main burner, replacing
them with new gas type correct diameter nozzles.
WARNING! It is mandatory to install copper gaskets.
- Re-install the main burner
- On the electronic board, switch
J MET-GPL
jumper to
GPL
position (see pic. 19).
Adjusting the boiler from LPG to methane
- Remove the main burner
- Remove main burner nozzles from main burner replacing
them with new gas type correct diameter nozzles.
WARNING! It is mandatory to install copper gaskets.
- Re-install the main burner;
- On the electronic board, switch
J MET-GPL
jumper to
MET
position (see pic. 19).
A) Max output gas valve adjustment
- Check gas mains supply pressure (refer to NOZZLE-
PRESSURE section on page 10);
- remove plastic cap
C
(pic. 17), which is positioned on top
of the modulating coil and protects gas valve pressure
adjusting nut and screw;
- Connect a manometer to
V
check in pic. 18;
- Adjust
R
screw (pic. 20) to MAX by rotating it fully
clockwise after removing the cap;
- Select “winter” boiler operation by means of no. 9 knob
(pic. 1);
- Start boiler in “chimney sweep” mode (see § 3.2.12.1);
- Turn nut
K
(external) clockwise in order to increase nozz-
le pressure and vice-versa (pic. 17b);
- In LPG-fired boilers, turn brass nut
K
fully clockwise.
B) Min output gas valve adjustment
- Disconnect the electrical wiring to modulation coil (
M
in
pic. 18);
- Turn the burner on and check
MIN
pressure according to
NOZZLE PRESSURE chart on page 10;
- In order to adjust pressure, hold nut
K
still by means of
a 10 mm tool, turn screw
W
clockwise to increase and
counter-clockwise to decrease gas pressure (pic.17b);
- Re-connect electrical wiring to modulation coil (M in
pic.8).
C) Final settings
- Turn
P ACC
screw (
S
in pic. 20) to middle set point, exit
the “chimney sweep” mode and check burner ignition to
be correct and silent: should it result incorrect or noisy,
increase or decrease ignition power by acting on
P ACC
adjuster (clockwise to increase, counter-clockwise to de-
crease);
- Re-check for correct min and max gas valve pressure
values;
- Adjust as necessary;
- Install plastic protective cap
C
(pic.17b);
- Close gas pressure checks;
-
Check for gas leaks.
pic. 19
J
pic. 18
M
V
pic. 17b
W
K
pic. 17
C
pic. 20
S
R
