33
3-3
3-4
3-5
+
+
3
12
1
P1
2
P3
4
INS
TALLER
US
ER
MAINTEN
AN
CE TECHNI
CI
AN
P.C.B.
Zones management P.C.B.
Key:
13 - Relay functioning signal LED (H1 ÷ H7)
14 - Zones management board functioning mode selectors
15 - Additional mixed zone flow temperature adjustment trim-
mer (optional) with external probe
16 - Mixed zone flow temperature adjustment trimmer with
external probe.
17 - Board functioning status signal LED
18 - Board functioning status signal LED
19 - Board functioning status signal LED
20 - Board power supply signal LED
SIT 848 Gas Valve
Key:
1 - Gas valve inlet pressure point
2 - Gas valve outlet pressure point
3 - Off/Set adjustment screw
4 - Pressure regulator connection (PR)
12 - Outlet gas flow rate regulator
Key:
4 - Fuse 3.15 AF
5 - S34 Selector:
On = external probe;
Off = system supervisor