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29
AST 14 C 255/00
SECT. 4
GAS SETTING AND PARAMETERS
4.1 GAS VALVE SETTING
To set the gas valve, proceed as follows:
check supply static pressure by means of the inlet pressure measurement point
E referring to the "setting" table on page 9, according to the type of fuel used
(pressure values lower than requested do not guarantee proper boiler operation);
check that the heating maximum output set with the parameter P7 is 100% (to
view or edit this parameter, refer to the sequence described in the "parameter
editing" paragraph, on page 33);
switch heating system on with the ambient thermostat;
ignite boiler in the “flue cleaning” mode (see following paragraph);
with the pressure gauge in the inlet pressure measurement point E, check supply
dynamic system pressure while the boiler is working (in case the pressure is too
low, boiler proper operation is not guaranteed);
remove the plastic cover protecting the adjustment screws at the top of the
modulation coil;
then connect the pressure gauge to the gas outlet pressure measurement point D
after closing the inlet pressure measurement point;
turn the maximum output screw C to increase (screw in) or decrease (loosen) the
maximum pressure, making reference to the "setting" on page 9;
electrically
disconnect
one
of modulation coil connectors to operate the boiler at
the minimum output;
adjust
the minimum pressure by turning the screw B of the gas valve (keep the
external screw C fixed). Make reference to the "setting" table as usual;
re-connect connector to modulation coil and check maximum pressure again;
disconnect the pressure gauge and check for any gas leakage both on the
pressure measuring points and on the gas valve connection fly nuts;
refit protection cover;
quit the "flue cleaning" function by pressing the
“reset” key;
in case parameter P7 has been edited, set the
correct value again;
switch the heating system off with the ambient
thermostat.
