QHT RIVA FP Service Instructions Manual page 39

Third Part
D.h.w. ˜ow switch, ÿlter and ˜ow
13
limiter
Function
1
The d.h.w. ˜ow switch A in Fig. 1 is a devicethat gener-
ates an electrical signal when hot water is drawn.
Fig. 1
When the ˜ow rate through the d.h.w. circuit reaches
about .6 gal/min', thefloat 6 (Fig. 3) is drawn to-
wards the right.
The resulting magnetic ÿeld of ring 5 increases and re-
aches the ˜ow switch sensor 1.
The sensor generates an electrical signal that switches
the boiler d.h.w operation ON.
The state of the sensor isalso indicated by meansof the
lamp B placed on the sensor body.
Fig. 2
RIVA FP SERVICE MANUAL - REV A
(edition-0106)
2
1 Flow switch sensor
2 Body
3 O---ring
4 Spring
5 Magnetic ring
6 Float
7 Threaded ring
8 Flow limiter (optional acces sory)
9 Filter
10 Spri n g seat
A
Fig. 3
3
Warning: isolate the boiler from the mains
electricity supply before removing any
covering or component.
n Flow switch sensor operation
B
1 Remove the front panel of the case.
2 Switch on the boiler and open a d.h.w. tap. The
lamp B (Fig. 2) placed on the sensor body is
switched on when the ˜ow rate reachesabout
C 4
Warning: isolate the boiler from the mains
electricity supply before removing any
covering or component.
1 Remove the front panel of the case.
2 Disconnect the connector C (Fig. 2) and remove
the sensor by delicately lifting up.
DHW Flow Switch and Filter
Nomenclature and location of parts
(Fig. 3)
Checks
gal /min'.
Removal of the f
low switch sensor
1
2
3
4
5
6
7
8
9
.6
10-1