Primary Circuit Flow Switch; Function; Checks; Removal - Biasi Riva Plus HE M296.24SR/C Service Manual

10

primary circuit flOw switch

10 .1 function

The Primary circuit pressure switch (A in Figure 10.1) function
is to check the presence of water in the primary hydraulic circuit
and that the pressure is above the minimum.
i
figure 10 .1
This device is connected to the electronic control p.c.b. and if, it
does not activate the control board will indicate that a fault condi-
tion (see section "Operation lights" page 17) has occurred.

10 .2 checks

warning: isolate the boiler from the mains electrici-
ty supply before removing any covering or compo-
nent .
Electrical check
It is possible to verify the general operation of the switch by
measuring the electric resistance between the contacts C and
N.O. of the switch.
1 Measure the electrical resistance between the tabs marked C
and N.O. (Figure 10.2).
The contact must close (resistance zero) with c.h. pressure of
0,35 bar or higher.
n .O .
figure 10 .2
- 26 -
Primary circuit flow switch
a
c

10 .3 removal

warning: isolate the boiler from the mains electrici-
ty supply before removing any covering or compo-
nent .
1 Remove the front and right hand side panels of the case, turn
off the flow and return isolation valves and empty the primary
circuit.
2 Remove the fixing spring B (Figure 10.3) and remove the pri-
mary circuit pressure switch A.
3 Disconnect the connectors.
a
b
figure 10 .3
4 Reassemble the primary circuit pressure switch in reverse
order of removal.
warning: to lubricate the O-ring gaskets exclusively
use a silicone base grease compatible to be in con-
tact with foods and approved by the local water au-
thorities .