Installation & Servicing instructions
AT
AG XL
5
description components
figure 1.a
1
heat exchanger 1 (All types OSS4)
2
heat exchanger 2 (XL110: OSS2, XL140:OSS4)
3
ignition unit
4
fan unit
5 damper
6
gas valve
7
automatic air vent
8
main switch 230V
9
boiler control unit
10 control unit MMI
11 connection terminal
12 connection terminal cascade bus communication
13 siphon
14 circulation pump
15 gas isolation valve (in optional boiler connections set)
16 service valves flow/return (in optional boiler connections set)
17 fill and drain valve (in optional boiler connections set)
18 safety valve (in optional boiler connections set)
19 flue connection (concentric)
20 air supply (for parallel flue connection)
21 collective flue pipe
22 information plate
T1 flow sensor
T1a secondary flow sensor (only OSS4)
T2 return sensor
P1 water pressure sensor
G
gas pipe
A
flow pipe CH
R
return pipe CH
C
condensate drain pipe
1
2
3
4
5
6
7
8
10
9
11
12
13
14
3
4
5
6
7
G C
A
R
15
16
18
17
22
21
20 19
T1a
T2
P1
T1
