Fitting A Room Thermostat; Gas Change Modalities - Baxi Luna 3 Avant Series Instructions For The User And The Installer

17. FITTING A ROOM THERMOSTAT

To connect the room thermostat to the boiler terminal block, proceed as follows:
• reach the power supply terminal block (fi gure 10);
• connect the room thermostat to the terminals (1) - (2) and remove the jumper.
A Qualifi ed Service Engineer may adapt this boiler to operate with natural gas (G. 20) or with liquid gas (G. 31).
The procedure for calibrating the pressure regulator may vary according to the type of gas valve fi tted (honeywell or SIT;
see fi gure 11).
Carry out the following operations in the given sequence:
A) Substitute the main burner injectors
• carefully pull the main burner off its seat;
• substitute the main burner injectors and make sure you
tighten them to avoid leakage. The nozzle diameters are
specifi ed in table 1.
B) Change the modulator voltage
• setting F02 parameter according to the gas used as de-
scribed in section 20.
C) Pressure adjusting device setting
• connect the positive pressure test point of a differential
(possibly water-operated) manometer to the gas valve
pressure test point (Pb) (Figure 11); connect, for sealed
chamber models only, the negative pressure test point of
the manometer to a "T" fi tting in order to join the boiler
adjusting outlet, the gas valve adjusting outlet (Pc) and the
manometer. (The same measurement can be carried out
by connecting the manometer to the pressure test point
(Pb) after removing the sealed chamber front panel); If you
measure the pressure of burners in a different way you
may obtain an altered result in that the low pressure cre-
ated in the sealed chamber by the fan would not be taken
into account.
C1) Adjustment to nominal heat output
• open the gas tap;
• press button (fi gure 1) and set the boiler in winter mode
(section 3.2);
• open a hot water tap to reach a minimum 10 l/min fl ow rate
or ensure that maximum heating requirements are set;
• remove the modulator cover;
• adjust the tube brass screw (a) Fig. 12 to obtain the pre-
sure settings shown in table 1;
• check that boiler feeding dynamic pressure, as measured
at the inlet gas valve pressure test point (Pa) (Figure 11) is
correct (37 mbar for propane gas G.31, 20 mbar for natural
gas G20);
BAXI - 925.200.1
925.492.2

18. GAS CHANGE MODALITIES

Honeywell valve
mod. VK 4105 M
SIT valve
mod. SIGMA 845
Pc
Pb
Pa
Figure 11
INSTRUCTIONS PERTAINING TO THE INSTALLER
15
GB
HU
CZ