Temperature Probe; Function; Checks; Removal - Biasi Parva HE M96.24SM/P 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. 69.
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. 69
On the boiler there are two Temperature probes. One
on the output of the primary heat exchanger (c.h. Tem-
perature probe) A in Fig. 70 and Fig. 71; one on the out-
put of the d.h.w. heat exchanger (d.h.w. Temperature
probe) B in Fig. 70 and Fig. 71.
c.h.
return
Fig. 70
ûC
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 brass group where the
Temperature probe is located and check the electrical
resistance according to the graph in Fig. 69.
15.3

Removal

Warning: isolate the boiler from the mains
electricity supply before removing any
covering or component.
1 To remove the Temperature probes remove the
front panel of the case.
2 To remove the c.h. Temperature probe empty the
primary circuit of the boiler.
To remove the d.h.w. Temperature probe empty
the d.h.w. circuit of the boiler.
3 Remove the electric connector of the Temperatu-
re probe and unscrew it.
4 Reassemble the Temperature probe carrying out
the removal operations in reverse order.
A
Fig. 71
B
B
31