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TemperaTure probe
15 temperature prObe
15 .1 function
The Temperature probe has the function of converting the tem-
perature of the water in the hydraulic circuit where it is installed
into an electrical signal (resistance).
The relation between temperature and electrical resistance is
stated in Figure 15.1.
figure 15 .1
1000
1500
2000
2500
3000
3500
4000
4500
5000
5500
6000
6500
7000
7500
8000
8500
9000
9500
10000
10500
11000
11500
12000
12500
20 25 30 35 40 45 50 55 60 65 70 75 80 85 90 95 100
Ω
°C
On the boiler there are four Temperature probes. Two on the in-
put/output of the primary condensing heat exchanger (c.h. Tem
-
perature probe) A and B in Figure 15.2 and Figure 15.3; two on
the input/output of the d.h.w. heat exchanger (d.h.w. Tempera
-
ture probe) C and D in Figure 15.2, Figure 15.4 and Figure 15.5.
figure 15 .2
c.h.
flow
c.h.
return
d.h.w.
inlet
d.h.w.
outlet
a
b
c
d
15 .2 checks
Temperature-resistance relationship
warning: isolate the boiler from the mains electrici-
ty supply before removing any covering or compo-
nent .
Disconnect the cable from the Temperature probe.
Measure the temperature of the pipes F and H (only c.h. Tem-
perature probe) where the Temperature probes are located and
check the electrical resistance according to the graph in Figure
15.1.
15 .3 removal of the c .h . temperature probes
warning: isolate the boiler from the mains electrici-
ty supply before removing any covering or compo-
nent .
1 Remove all the case panels and the sealed chamber lid.
2 Empty the primary circuit of the boiler.
3
Remove the electric connector G and E and unscrew the c.h.
Temperature probes A and B (Figure 15.3).
4 Reassemble the c.h. Temperature probes carrying out the re-
moval operations in reverse order.
figure 15 .3
a
b
e
f
G
h
15 .4 removal of the d .h .w . temperature probes
warning: isolate the boiler from the mains electrici-
ty supply before removing any covering or compo-
nent .
removal of the d .h .w . Outlet temperature probe
1 Remove the front panel of the case and lower the control
