10
F
ault
finding
Ins
tructions
for
ins
tallation
and
servicing
aquaPL
US
VUI
3
62
-7
42
Ensure boiler main
ON/OFF control is set
to position "1"
Is there a display on
the LCD Panel?
Yes
Go to sheet C
Check electrical supply, appliance fuses and on/off control
No
Is 230VAC present across
terminals L and N?
Yes
Is 230VAC present across
terminals 3 and 5?
Yes
Is voltage between
16-26 VDC present across
terminals 8 and 9?
Yes
Is 5 VDC present between
5V and GND test points
on electronic board?
Replace LCD display
Yes
No
Repair external fault
Is the continuity
across fuse F1?
Go to sheet B
Does ON/OFF knob
operate switch on
electronic board
Boiler ON/OFF control
defective,
change electronic
board
Replace switch
mechanism
No
No
No
Yes
Yes
Note 1:
For test purposes, disconnect
external controls from terminal
3 - 4 and replace with a bridge
between these terminals.
It appliance then operates, the
fault is with the external controls.
Sheet A
Is there continuity
across fuse F3?
No
No
Replace electronic
board
No
Check transformer
Replace if
necessary
Yes
834702_33GB_012005.qxd 09.03.2005 16:26 Uhr Seite 42
