Fault finding 10
Instructions for installation and servicing aquaPLUS VUI 362-7
47
Does flame indicator glow and
flames increase in size to full gas
rate after approx. 2 mins?
Ye
s
Does bur
ner flame modulate/ go
out when radiator temperature
control is tur
ned left to the
horizontal position at flow
temperature of approx.
°
50 C?
Ye
s
Does heating flow pipe
temperature rise?
Go to sheet G
Ye
s
Check operation of bur
ner and modulation
Ensure flow and retur
n ser
vice
valves are open
No
No
No
Replace electronic board
No
Check operation of boiler in DHW
mode, does flame increase in size
to full rate?
Ye
s
Check par
tial load
setting
No
Check diagnostic code D.22
(see page 39) equals 1
No
Go to sheet G
Ye
s
Check connections and
modulator
, replace gas valve if
bur
ner still fails to increase to full
rate
Tur
n main ON/OFF control to
the "0" position
Ye
s
Inser
t a small screwdriver
through the hole in the front of
the diver
ter valve and hold
blade lightly against spindle
Tur
n "ON" the main ON/OFF
control
Does spindle move?
Ye
s
Replace electronic board
Replace diver
ter valve
No
Sheet F
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