1.6
Main water circuit
1
2
3
4
5
6
8
7
13
M
U
KEY:
M System delivery
R System return
U Domestic hot water outlet
E Domesti hot water inlet
S Safety valve outlet
G Gas supply
Fan
1
Heat exchanger (mono-thermal)
2
Dual sensor (thermal safety/delivery)
3
Combustion chamber
4
Gas valve
5
Domestic hot water heat exchanger
6
Domestic hot water sensor
7
Diverter valve
8
Automatic bleed valve
9
Pump
10
Domestic hot water flow meter
11
Domestic hot water filter
12
System filling
13
System relief valve
14
Water pressure switch
15
Boiler drain
16
System expansion vessel
17
Water pressure gauge
18
8
17
18
9
10
15
14 S
11
12
G
E
R
Fig. 3
1.7
Sensors
The sensors installed have the following characteristics:
– Dual sensor (thermal safety/output) NTC R25°C; 10kΩ β25°-
85°C: 3435
– domestic hot water sensor NTC R25°C; 10kΩ β25°-85°C: 3435
– External temperature sensor NTC R25°C; 10kΩ β25°-85°C:
3435
Correspondence of Temperature Detected/Resistance
Examples of reading:
TR=75°C → R=1925Ω
TR=80°C → R=1669Ω.
TR
0°C
1°C
2°C
0°C 27279
26135
25044
10°C
17959
17245
16563
20°C
12090
11634
11199
30°C
8313
8016
7731
5828
5630
5440
40°C
50°C
4161
4026
3897
60°C
3021
2928
2839
2229
2164
2101
70°C
80°C
1669
1622
1577
1266
1232
1199
90°C
100°C
973
16
1.8
Expansion vessel
The expansion vessel installed on the boilers has the following
characteristics:
Description
Total capacity
Prefilling pressure
Useful capacity
Maximum system
content (*)
(*) Conditions of:
Average operating temperature 70°C (with high temperature
system 80/60°C)
Start temperature at system filling 10°C.
m
CAUTION
– For systems with water content exceeding the
maximum system content (as indicated in the table)
an additional expansion vessel must be prearranged.
– The difference in height between the relief valve
and the highest point of the system cannot exceed
6 metres. If the difference is greater than 6 metres,
increase the prefilling pressure of the expansion
vessel and the system when cold by 0.1 bar for each
meter increase.
3°C
4°C
5°C
6°C
7°C
8°C
24004
23014
22069
21168
20309
19489
15912
15289
14694
14126
13582
13062
10781
10382
9999
9633
9281
8945
7458
7196
6944
6702
6470
6247
5258
5082
4913
4751
4595
4444
3773
3653
3538
3426
3319
3216
2753
2669
2589
2512
2437
2365
2040
1982
1925
1870
1817
1766
1534
1491
1451
1411
1373
1336
1168
1137
1108
1079
1051
1024
U/M
Brava One 40 BF
l
9,0
kPa
100
bar
1,0
l
5,0
l
124
EN
9°C
18706
12565
8622
6033
4300
3116
2296
1717
1300
998