Checks; Removal Of The On; Removal Of The Gas Valve - Biasi M96.24SM/B Service Manual

Modulating gas valve
12.4

Checks

Warning: isolate the boiler from the mains
electricity supply
covering or component.
Check the modulation operator coil
n
1 Remove the front panel of the case.
2 Disconnect the connectors B (Fig. 48) from the
modulating operator and measure the electrical
resistance of the coil. Its electrical resistance
value must be approx. 80 W*.
Check the on---off operators coils
n
1 Remove the front panel of the case.
2 Disconnect the electrical connector C (Fig. 48).
3 Measure the electrical resistance between the
connector pins of the on---off operators as illus-
trated in Fig. 46.
Upper on---off operator
approx. 6 400 W*
Lower on---off operator
approx. 920 W*
* at ambient temperature.
Fig. 46
12.5
Removal of the
Warning: isolate the boiler from the mains
electricity supply
covering or component.
1 Remove the front panel of the case as explained
in the section 2.3 of this manual.
Disconnect the connector D (Fig. 47).
2
3 Unscrew the screw E and remove on---off oper-
ator coils.
4 Reassemble the coils carrying out the removal
operations in reverse order.
D
Fig. 47
26
before removing
on---off operators coils
before removing
E
12.6

Removal of the gas valve

any
Warning: isolate the boiler from the mains
electricity
covering or component.
1 Remove the front panel of the case as explained
in the section 2.3 of this manual.
2 Disconnect the connectors B and C (Fig. 48).
3 Turn off the gas supply and disconnect the gas
isolation cock connector from the inlet port of the
gas valve.
4 Unscrew the connectors F and remove the pipe
G
Unscrew the screws H and remove the valve.
5
6 Reassemble the valve carrying out the removal
operations in reverse order.
After any service operation on the components of
the gas circuit check all the connections for gas
leaks.
Warning: After cleaning or replacement as
detailed above, if it deemed necessary to
undertake a combustion analysis, refer to
the appropriate chapter Maintenance of the
any
installation instructions manual.
Fig. 48
supply before
F C B
H
removing any
G