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A Qualified Service Engineer may adapt this boiler to operate with natural gas (G20) or with liquid
gas (G31).
Carry out the following operations in the given sequence:
1) Calibration of the maximum heat output. Check that the CO
2
measured on the flue, with the boiler
operating at the maximum heat output, is the same as that shown in table 1. Otherwise, turn the
regulation screw (V) on the gas valve. Turn the screw clockwise to increase the concentration of
CO
2
and anticlockwise to reduce it.
2) Calibration of reduced heat output. Check that the CO
2
measured on the flue, with the boiler
operating at the minimum heat output, is the same as that shown in table 1. Otherwise, turn the
offset regulation screw (K) on the gas valve. Turn the screw clockwise to increase the concentration
of CO
2
and anticlockwise to reduce it.
16. Gas change modalities
020429_0400
Figure 15
020523_0700
Figure 14
Pi:
Gas supply pressure connection point
PO:
Gas pressure to burner connection point
P:
Pressure connection point for
measurement of the OFFSET
Pl:
Air signal input from fan
V:
Gas flow adjuster screw
K:
OFFSET adjuster screw
To simplify calibration of the gas valve, the “calibration function” can be set directly on the boiler
control panel by proceeding as follows:
1) Press the
keys (2-3) together until the display shows the pointer “ ” alongside the
symbol (about 6 seconds).
2) Press the
keys to set the fan speed at the minimum and maximum heat output (%PWM);
N.b - to set the minimum and maximum heat output quickly, press the
keys respectively;
3) press either of the two
keys to exit the function.