QHT RIVA FP Service Instructions Manual page 36

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Third Part
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9) Start the boiler and rotate the minimum gas
pressure adjustment (B in Figure 2) until you
obtain the required pressure (by rotating
clockwise the pressure increases).
10) Turn the boiler off and re-connect the wire to
the modulating operator.
11) Start the boiler and check again the
maximum gas pressure setting.
12) Turn the boiler off and disconnect the gauge.
Important: after the gas pressure checks and
any adjustment operations, all of the test
points must be sealed.
4 Checks
A Check the modulation operator coil
1) Remove the front panel of the case.
2) Disconnect the connectors D (Figure 2) from
the modulating operator and measure the
electrical resistance of the coil. Its electrical
resistance value must be approx. 114 Ω*.
B Check the on-off operators coils
1) Remove the front panel of the case.
2) Disconnect the Ignition device N (Figure 4).
3) Measure the electrical resistance between the
connector pins of the on-off operators as
illustrated in Figure 5.
On-off operator
approx. 1 122 Ω*
* at ambient temperature
RIVA FP SERVICE MANUAL – REV A
N
Figure 4
Figure 5
(edition-0106)
5 Removal of the Gas Valve
1) Remove the front panel of the case.
2) Disconnect the connector D (Figure 2) and
remove the full sequence ignition device N
(Figure 4)
3) Turn off the gas supply and remove the gas
supply pipe O (Figure 6).
4) Loosen the connections Q (Figure 2 and 7)
and R (Figure 7).
5) Remove the gas pipe above the gas valve.
6) Loosen the screws P (Figure 6).
7) Remove the gas valve.
8) Reassemble the gas 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
Modulating Gas Valve
O
Figure 6
Q
Figure 7
detailed above, if it deemed
necessary to undertake a
combustion analysis.
P
R
8-2