Gas Conversion Methods - Baxi Fourtech Series Operating And Installation Instructions

The authorised Technical Assistance Service can convert this boiler to natural gas (G20) or liquid gas (G31).
The procedure for calibrating the pressure regulator varies slightly according to the type of gas valve fitted (HONEYWELL
or SIT, see figure 10).
Carry out the following operations:
A) replace the main burner nozzles;
B) change the modulator voltage
C) new max. and min. calibration of the pressure regulator.
A) Replace the burner injectors
in table 2.
B) Change the modulator voltage
F02 according to the gas used, as described in section 21;
C) Calibrate the pressure regulator
pressure test point (Pb) (Figure 10). Only for models with sealed chambers, connect the negative pressure test point
of the pressure gauge to a "T" fitting in order to join the boiler adjustment outlet, the gas valve adjustment outlet (Pc)
and the pressure gauge. (The same measurement can be made by connecting the pressure gauge to the pressure test
point (Pb) after removing the front panel of the sealed chamber). Measuring burner pressure using methods other than
those described could lead to incorrect results as the low pressure created by the fan in the sealed chamber would not
be taken into account.
C1) Adjustment to nominal heat output:
demand;
is correct (37 mbar for propane or 20 mbar for natural gas).
C2) Adjustment to reduced heat output:
output is achieved (see tab. 1);
C3) Final checks
SIT valve - mod. SIGMA 845
Figure 10
INSTRUCTIONS FOR FITTERS
19. GAS CONVERSION
10 litres a minute or make sure there is maximum heat
b) until a pressure value corresponding to reduced heat
50
Honeywell valve - mod. VK 4105 M
926.116.5 - en