30
21. Boiler schematic
Legend:
1
boiler drain point
2
manometer
3
siphon
4
central heating NTC sensor
5
105°C overheat thermostat
6
gas valve
7
flue-water exchanger
8
flame detector electrode
9
main burner
10
ignition electrode
11
air/gas mixture header
12
mixer with venturi
13
gas diaphragm
14
fan
15
flue thermostat
16
coaxial fitting
17
automatic air vent
18
flue joint
19
hydraulic pressure sensor
Figure 18
GAS
HEATING
INLET
HEATING
RETURN
CONDENSATION
DRAIN
SEALED CHAMBER
0411_0501