Checks; Removal Of The Gas Valve - Biasi Advance Plus 25C Service Manual

figure 11.10
25 Switch off the boiler and turn off the hot water tap(s).
26 Close the air-flue sampling points.
27 After adjustment fit the protective brass plug (C - Figure 11.2).
Important: after the gas pressure checks and any adjust-
ment operations, all of the test points must be sealed.

11.4 Checks

Warning: isolate the boiler from the mains electrici-
ty supply before removing any covering or compo-
nent.
Check the on-off operators coils
1 Remove the front panel of the case.
2 Disconnect the electrical connector E (Figure 11.2).
3 Measure the electrical resistance between the connector pins
of the on-off operators as illustrated in Figure 11.11.
Upper on-off operator
approx. 6400 *
Lower on-off operator
approx. 920 *
*at ambient temperature.
figure 11.11

11.5 Removal of the gas valve

Warning: isolate the boiler from the mains electrici-
ty supply before removing any covering or compo-
nent.
1 Remove the front panel of the case as explained in the sec-
tion 2.3, of this manual.
2 Disconnect the connector J (Figure 11.12).
- 32 -
GAS vALvE
C.h. / d.h.w.
function
figure 11.12
3 Turn off the gas supply and disconnect the gas isolation cock
4 Using pliers, remove the spring L and the rubber pipe M (Fig-
5 Unscrew the connector N (Figure 11.12), remove the fixing
6 Unscrew the screws K and remove the valve (Figure 11.12).
7 Reassemble the valve carrying out the removal operations in
Before fitting a new valve, it is advisable to preset it as fol-
lows.
8 Remove the brass plug and turn the plastic screw inside it
9 Turn it counter-clockwise 2 and 3/4 turns.
10 Adjust the gas valve using the flue analyser as described in
After any service operation on the components of the gas
circuit check all the connections for gas leaks.
L
J
K
connector from the inlet port of the gas valve.
ure 11.12).
fork O and remove the pipe P.
reverse order.
Warning: Be careful not to damage the oR gasket of
the gas pipe when inserting the pipe in the air box
(air/gas mixer).
fully clockwise until it stops. Do not overtight.
section 11.3.
Warning: After cleaning or replacement as detailed
above, it is deemed necessary to undertake a com-
bustion analysis as detailed in section 11.3.
o
P
N
m