7
1 6 System layout
1
2
3
5
4
6
7
9
8
11
12
10
18
19
20
13
14
22
21
23
24
16
15
25
26
27
28
17
1
Control panel
2
Single heating element
3
Control panel
4
Bus cable passage cable gland for the cascade
connection
5
Flue gas manifold
6
Gas manifold
7
System delivery manifold
8
Condensate drain manifold
9
System return manifold
10
Single heating element flue gas analysis outlet
11
Fan
12
Single heating element flue gas exhaust union
13
Automatic bleed valve
14
Safety thermostat
15
Drain cock
16
Manual diverting valve
17
Circulator (or 2-way valve)
18
Gas valve
19
Comburent air intake union
20
Gas cock
21
Flow probe
22
Ignition/detection electrode
23
Exchanger
24
Return probe
25
Exhaust flue probe
26
Differential water and minimum pressure switch
27
Return detection tap
28
Safety valve 5.4 bar