3.4
HYDRAULIC DIAGRAM
Key (Fig. 52):
1
- Gas valve
2
- D.H.W. flow switch
3
- Gas nozzle
4
- Flow limiter
5
- D.H.W. probe
6
- Condensate drain trap
7
- System filling cock
8
- D.H.W. heat exchanger
9
- System expansion vessel
10
- Positive (+) pressure point
11
- Venturi
12
- Flow probe
84
13
- Ignition / detection electrode
14
- Air intake pipe
15
- Flue probe
16
- Flue sample point
17
- Air sample point
18
- Burner
19
- Return probe
20
- Fan
21
- Air vent valve
22
- Boiler circulating pump
23
- Absolute pressure switch
24
- 3-way valve (motorised)
25
- By-pass
26
- System draining cock
27
- 3 bar safety valve
28
- 3 bar safety valve drain fitting signal
29
- Air vent valve drain
G
- Gas supply
AC
- Domestic hot water outlet
AF
- Domestic hot water inlet
SC
- Condensate drain
M
- System flow
R
- System return
52