Ferroli Sigma 30 FF 41-267-07 Installation And Servicing Instruction page 29

8.03 General test and fault finding chart
yes
eletrode
yes
sparks
boiler
yes
locks out
check for
continuity
through
overheat
thermostat
no
change
overheat
thermostat
yes
burner lights but
boiler continues to
spark and locks out
no
check resistance through coils of
1320 ohms between top two pins
2800 ohms between bottom two pins
no
change gas
valve assembly
fan runs
no
230V at live connection
no
no
yes
with fan running
electrical
connections to air
pressure switch
removed. check for
continuity between
common and
normally open
contacts of the air
pressure switch
yes no
yes
gas valve
Sigma
boiler does not work
of terminal block
yes
230V at switched
live connection of
terminal block
yes
230 v on grey wire of
block x5 on main pcb
yes
fan runs
no
230 v at both fan
terminals to earth
yes no
check air
pressure
switch and
change if
necessary
reverse
polarity
yes
no
check mains supply
no
resistance of the temp
sensor between 80
no
kohm at 80°c and
1mohm at 25°c
yes
change
main pcb
change sequence pcb
on gas valve
no
yes
retify
and fuse
check external
controls
no
change
temperature
sensore
no
has the
problem been
intermittent
at all
yes
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