Modulating gas valve
28
11.4
Checks
Warning: isolate the boiler from the mains
electricity supply before removing any
covering or component.
n
Check the modulation operator coil
1
Remove the front panel of the case.
2
Disconnect the connectors
B
(Fig. 47) from the
modulating operator and measure the electrical
resistance of the coil. Its electrical resistance
value must be approx. 80
W*.
n
Check the on---off operators coils
1
Remove the front panel of the case.
2
Disconnect the electrical connector
C
(Fig. 47).
3
Measure the electrical resistance between the
connector pins of the on---off operators as illus-
trated in Fig. 45.
Lower on---off operator
approx. 920
W*
Upper on---off operator
approx. 6 400
W*
* at ambient temperature.
Fig. 45
11.5
Removal of the
on---off operators coils
Warning: isolate the boiler from the mains
electricity supply before removing any
covering or component.
1
Remove the front panel of the case as explained
in the section 2.3 of this manual.
2
Disconnect the connector
D
(Fig. 46).
3
Unscrew the screw
E
and remove on---off oper-
ator coils.
4
Reassemble the coils carrying out the removal
operations in reverse order.
E
D
Fig. 46
11.6
Removal of the gas valve
Warning: isolate the boiler from the mains
electricity supply before removing any
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. 47).
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.
B
C
F
G
H
Fig. 47
Summary of Contents for RIVA PLUS M90S.24S
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