Vaillant VCW 2O Instructions For Installation And Servicing page 51

Flepeat the tollowing
checks:
A. Earth Continuity.
C. Polarily.
D. Besistance to Earth
according to Instructions
for British Gas
Multimeter.
ls voltage
2ZIO VAC
trom teminal
Does Main
Burner light?
Are external
Thermostats
tested?
Fleplacefaulty
Thermostat.
Ret. to note 5.
Check external
Thermostals accorclino
to lnstructions tor
'
British Gas
Multimeter.
Go to sheet 4
€*t
Overheat
:,t-Otf Device.
eef. lo note 2.
-:Eck contacts
d Overheat
:loff
Device.
a€i. to note 3.
Check that
Multiplugs @ arid
: ile clean, tight
ild mrrectly
:r:siti.cned. Ref.
note 4.
Note 2: For re.s€tting, press the black rubber butlon on right hand side of control box behind the
terminal box.
Note 3: For this purpose, open the control box as describ€d in Note 1. The overheat cut-off
device isiitt(i on right hand side ofthe control box- Checkitthe flat plugs ofthe overheat
cut-otl device are tight.
Nole 4: For this purpose, open the control box as described in Note 1 Pull off the multicontact
plugs A and B and check that not contact lugs are bent. It necessary, readiust contact
iugS and reset multicontact plugs again.
Note 5: To check, disconnecf contrclsystemlrom terminals 3 and 4, and replace with wire loopto
run boiler in heating mode.
5 1