Vaillant ecoTEC plus Instructions For Installation And Servicing page 24

4 Boiler installation sequence
NTC return
X 20/5 red
X 20/7 black
X 20/8 blue
Gas valve assembly
black
Electronic control box
Fig. 4.10 Mains Supply Connection
24
NTC flow
black link
X 20/18 red (24 Vdc)
X 20/9 blue (earth)
red
X20 X2
Ignition electrode
Fan unit
X 20/16 blue (earth)
X 20/4 grey (PWM)
X 20/3 black (hall signal)
X 20/17 red (24 Vdc)
Chassis earth
red
bus 24 V 230 V
green/yellow
green/ yellow
Instructions for installation and servicing ecoTEC plus 0020020828_07
green/ yellow
pump connection
fuse T2E
250 Volts