Fan And Air Pressure Device 11.61; Checks - QHT RIVA FP Service Instructions Manual

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Third Part
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Fan and Air Pressure Device 11.61

1) Function

2) Checks

3) Removal
1 Function
The Fan and air pressure device A (Figure 1)
used on the boiler carries out the following
fundamental functions:
O supplies the fan and checks its functioning by
means of the signal coming from the air
pressure switch.
O supplies the air pressure switch and makes it
commutate.
O supplies the safety thermostat.
The Fan and air pressure device is supplied by
the electronic control p.c.b. see Second part of
this manual chapter 6 (Circuit Voltages).
The Fan and air pressure device also has a
safety function and any wrong interventions or
tamperings could cause the boiler to function
under hazardous operating conditions.
The Fan and air pressure device can lock the
functioning of the boiler (lock state) and stop its
functioning up to the resetting intervention. The
lock is signalled by the lighting of the lock-out
signal lamp and the device can be reset only by
using the boiler reset button and the function
knob placed on the control panel.
Some components which are connected to the
device can activate the lock state. The causes of
a lock state could be:
O The intervention of the safety thermostat
(overheat of the primary circuit).
O The air pressure switch can temporarily stop
the ignition of the burner but allow its ignition
when the cause of the intervention has stopped.
2 Checks
A Fan and Air Press. Switch functioning device
With the boiler operating and the burner on, open
the negative pressure test point of the Venturi
device.
RIVA FP SERVICE MANUAL – REV A
(edition-0106) Fan and Air Pressure Device 11.61
At the moment of opening the burner must turn
off.
B Checking Voltages
Refer to Second part of manual chapter 6 to
determine the connector pins where to check the
supply voltages.
3 Removal
F
D
B
1) Remove the front panel of the case and lower
the control panel.
2) Open the control panel as explained in the
first section of the third part (General access
and emptying hydraulic circuits).
3) Disconnect the connectors B,C,D,E by
delicately flexing the hook present on one
side of each socket.
4) Loosen the screws F and remove the device.
5) Re-assemble the device following the removal
procedures in the reverse order.
A
E
C
Figure 1
F
6-1