14 D.h.w. Flow Switch, Filter And Flow Limiter; Function; Description And Location Of Parts - (Figure 14.2); Removal Of The Sensor - Biasi Advance Plus 25C Service Manual

d.h.W. fLoW SWITCh, fILTER ANd fLoW LImITER
14 d.h.W. fLoW SWITCh, fILTER ANd
fLoW LImITER

14.1 function

The d.h.w. flow switch A in Figure 14.1 is a device that generates
an electrical signal when hot water is drawn.
figure 14.1
When the flow rate through the d.h.w. circuit reaches about 2,5
litres/min', the sensor closes the electric contact that switches
the boiler d.h.w operation ON.
14.2 description and location of parts - (figure
14.2)
1 Flow switch plug
2 O-ring
3 Flow limiter (Advance Plus 30C. Advance Plus 35C. optional
accessory)
4 Body with flow meter turbine
5 Filter
1
2 3
figure 14.2

14.3 Removal of the sensor

Warning: isolate the boiler from the mains electrici-
ty supply before removing any covering or compo-
nent.
figure 14.3
A
1 Remove the front panel of the case.
2 Disconnect the connectors B and remove the sensor holder
3 Remove the sensor.

14.4 Checks

5
figure 14.4
4
2
1 Remove the front panel of the case.
2 Don't disconnect the connectors B
3 Measure the electrical frequency at the leads of the sensor.
C (Figure 14.3).
Warning: isolate the boiler from the mains electrici-
ty supply before removing any covering or compo-
nent.
Sensor operation
0..32 Hz
(without flow rate)
33..200 Hz
(witht flow rate)
wh = white
bu = blue
rd = red
Without flow rate the electrical frequency must be 0÷32Hz.
With flow rate the electrical frequency must be 33÷200Hz.
E
d
B
C
bu
wh
rd
B
5V
rd
wh
- 35 -
bu