Biasi RIVA COMPACT M90E.24S Service Manual page 26

Modulating gas valve
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. 5) 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. 5).
3 Measure the electrical resistance between the
connector pins of the on---off operators as illus-
trated in Fig. 3.
Upper on---off operator
approx. 6 400 Ω*
Lower on---off operator
approx. 920 Ω*
* at ambient temperature.
Fig. 3
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. 4).
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. 4
24
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. 5).
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
5 Unscrew the screws H and remove the valve.
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. 5
supply before removing
G
F
H
any
B
C