Vaillant ecoTEC plus 612 Instructions For Installation And Servicing page 27

NTC
flow
X 20/5 red
X 20/7 black
X 20/8 blue
X 20/7 black
Gas valve assembly
X 2/10 black
X 2/14 brown
X 2/9 black
X 2/11 red
X 2/12 green
X40
X 20
Electronic control box
Fig. 4.17 Connection wiring ecoTEC system boiler
Instructions for installation and servicing ecoTEC / 839592_09
NTC
return Ignition electrode
Thermal fuse
X 20/18 red (24 VDC)
X 20/9 blue (earth)
Hot water
contact C1/C2
Water pressure sensor
X41
X 2
Boiler installation sequence 4
X 20/13 black
X 20/12 black
Fan unit
X 20/16 blue (earth)
X 20/4 grey (PWM)
X 20/3 black (Hall signal)
X 20/17 red (24 VDC)
X 2/4 orange
X 2/10 black
— + 7 8 9 L N 3
BUS 24V 230V
Plug
in
coupling
tank NTC
connection
4 5
Pump
27