Checks; Removal Of The Gas Valve - Biasi GARDA M90F.24S Service Manual

10.4

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. 45) from the
modulating operator and measure the electrical
resistance of the coil. Its electrical resistance
value must be approx. 80 Ω*.
Check the on---off operators coils
n
1 Remove the front panel of the case.
2 Disconnect the electrical connector C (Fig. 45).
3 Measure the electrical resistance between the
connector pins of the on---off operators as illus-
trated in Fig. 43.
Upper on---off operator
approx. 6 400 Ω*
Lower on---off operator
approx. 920 Ω*
* at ambient temperature.
Fig. 43
10.5 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. 44).
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. 44
before removing
on---off operators coils
before removing
E
10.6

Removal of the gas valve

Warning: isolate the boiler from the mains
any
electricity
covering or component.
1 Remove the front panel of the case as explained
in the section 2.3 of this manual.
Disconnect the connectors B and C (Fig. 45).
2
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 refer to section Combustion
analysis check in the chapter Maintenance of
the installation instructions manual.
any
Fig. 45
Modulating gas valve
supply before removing
F
H
any
G
B
C
23