Temperature Probe; Function; Checks; Removal Of The C.h.temperature Probe - Biasi Activ A 25C Service Manual

15

Temperature probe

15.1

Function

The Temperature probe has the function of converting
the temperature of the water in the hydraulic circuit
where it is installed into an electrical signal (resistance).
The relation between temperature and electrical resis-
tance is stated in Fig. 15.1.
Ω
12500
12000
11500
11000
10500
10000
9500
9000
8500
8000
7500
7000
6500
6000
5500
5000
4500
4000
3500
3000
2500
2000
1500
1000
500
20 25 30 35 40 45 50 55 60 65 70 75 80 85 90 95 100
Fig. 15.1
On the boiler there are two Temperature probes. One
on the output of the primary condensing heat ex-
changer (c.h. Temperature probe) A in Fig. 15.2 and
Fig. 15.3; one on the output of the d.h.w. heat ex-
changer (d.h.w. Temperature probe) B in Fig. 15.2 and
Fig. 15.4.
c.h.
return
Fig. 15.2
A
c.h. d.h.w. d.h.w.
flow inlet outlet
15.2

Checks

Temperature---resistance relationship
n
Warning: isolate the boiler from the mains
electricity supply before removing any
covering or component.
Disconnect the cable from the Temperature probe.
Measure the temperature of the pipe C (only c.h. Tem-
perature probe) where the Temperature probe is lo-
cated and check the electrical resistance according to
the graph in Fig. 15.1.
15.3

Removal of the c.h.Temperature probe

Warning: isolate the boiler from the mains
electricity supply before removing any
covering or component.
1 Remove all the case panels.
2 Empty the primary circuit of the boiler.
Remove the electric connector D and remove the
3
c.h. Temperature probe A --- Fig. 15.3
4 Reassemble the c.h.Temperature probe carrying
out the removal operations in reverse order.
˚C
D
Fig. 15.3
15.4

Removal of the d.h.w.Temperature probe

Warning: isolate the boiler from the mains
electricity supply before removing any
covering or component.
1 Remove the front panel of the case and lower the
control panel.
2 Empty the d.h.w circuit of the boiler.
Remove the electric connector E
3
Remove the fork F and pull the d.h.w. Tempera-
4
B
ture probe B --- Fig. 15.4
5 Reassemble the d.h.w. Temperature probe carry-
ing out the removal operations in reverse order.
Warning: to lubricate the O-- ring gaskets
exclusively use a silicone base grease
compatible to be in contact with foods and
approved by the local water Authorities.
A
C
35