80
INS
TALLER
U
SER
M
AINTEN
AN
CE
TECHNI
CI
AN
TECHNI
CAL
D
AT
A
3.4 HYDRAULIC DIAGRAM
51
Key (Fig. 51):
1
- Gas valve
2
- Condensate drain trap
3
- 3 bar safety valve
4
- System draining cock
5
- System expansion vessel
6
- Return probe
7
- Air / gas mixer
8
- Gas nozzle
9
- Fan unit with non-return valve on the flue gas
10
- Ignition/detection electrode
11
- Double flue probe sensor
12
- Flue hood
13
- Flue sample point
14
- Air sample point
15 - Burner
16
- Air / gas manifold
17
- Non-return valve on flue gas
18
- Air intake pipe
19
- Flow probes
20
- Air vent valve
21
- Boiler circulating pump
22
- System pressure switch
23
- Stainless steel storage tank
24
- Magnesium anode
25
- 3-way valve (motorised)
26
- Domestic hot water expansion vessel
27
- D.H.W. probe
28
- Stainless steel coil for storage tank
29
- 8 bar safety valve
30
- Cold water inlet non-return valve
31
- Storage tank draining valve
32
- System filling cock
33 - By-pass
G
- Gas supply
AC
- Domestic hot water outlet
AF
- Domestic hot water inlet
SC
- Condensate drain
M
- System flow
R
- System return