F40
''HIGH WATER
PRESSURE
FAULT
''
It occurs when water
pressure sensor is below than
(0.4 bar). Check whether water
pressure value is > 3.3± 0.3 bar for
central heating circuit
from LCD.
Replace the
main
board.
NO
YES
Pressure sensor
cables may
be
not
mounted, or there may be a
loose
contact. Check the
cables
NO
Replace the cables in
case of any problem.
Remove electrical
connector on water pressure sensor
when the power of the
boiler
is still on,
and measure the DC voltage. Check
whether the voltage is in the
range of 4.9-5.1 V DC.
YES
Replace the
main
board.
NO
YES
Replace the pressure sensor. Check
whether
fault
is gone.
Check whether the pressure in
expansion tank
is
over 0.5
bars.
If
fault
is gone, the
problem
is
pressure
sensor.
YES
NO
Pressurize
until the pressure
reaches to 1 bar. (If any pressure
drop occurs within 6 months in
the expansion tank where gas is
added, expansion tank must be
replaced)
Check the 3 bar safety valve.
It
may be not working.
NO
YES
NO
Check the filling
loop
.
There may
be a leakage from DHW to CH
when filling loop is completely
closed. Replace it if needed.
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