43
22
External temperature probe
(optional)
22.1
Function
The External temperature probe if fitted, allows to ad-
just automatically the temperature of the c.h. flow with
reference to the external temperature.
The relationship between the external temperature and
the c.h. flow temperature is represented by the coeffi-
cient K (Fig. 22.1) that can be set between 0 and 6.
More details concerning the coefficient K and the set-
ting procedure are given in the
Commissioning
section
of the installation manual.
The coefficient K is factory set to 0 that is the setting
for the operation with no external temperature
probe fitted.
20
30
40
50
60
70
80
20 15 10 5
0
---5 ---10 ---15 ---20 ---25
K=4 K=3
K=2
K=1
K=0,5
K=1,5
K=6
External temperature
˚
C
C.h. flow temperature
˚
C
Fig. 22.1
22.2
Checks
Warning: isolate the boiler from the mains
electricity supply before removing any
covering or component.
Disconnect the cable from the External temperature
probe.
Measure the external temperature where the External
temperature probe is located and check the electrical
resistance according to the graph in Fig. 22.2.
500
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
Fig. 22.2