Vaillant ecoTEC VU 656/4 - Connection Diagrams

23Installation and maintenance instructions ecoTEC 0020029173_01
5.8.5 Connection diagrams
Flow switch
P
X20
X2
1
2
4
+
Signal
-
1
2
3
4
5
4
2
5
9
11
12
13
1
17
3
4
16
5
7
8
12
13
14
6
10
18
9
15
2
14
10
Coding resistance
1210 Ω
X11
brown
black
black
black
black
black
black
black
grey
red
red
red
blue
blue
blue
black
black
black
black
red
red
green
green
orange
violet
Flow sensor
Return sensor
Gas valve
green/yellow
Igniter
X14
Ignition electrode
Appliance earth
natural
black
Fan
Mains
Earth
Hall signal
PWM signal
+24V
Flow rate sensor
Water pressure sensor
Cylinder thermostat (connection)
1)
“C1-C2”
Cylinder
NTC sensor
1)
Low-voltage plug
Fig. 5.16 Connection diagram of ecoTEC
(continued on next page)
1) You must not use both the C1/C2 and the cylinder sensor connections!
Installation 5