Sime FORMAT SYSTEM 25 HE Installation And Servicing Instructions page 24

5.5 C.H. MODE - FAULT FINDING
Start from cold Rotary switch set to WINTER position.
Room thermostat (if fitted) calling for heat.
C.H. thermostat set to maximum position.
Clock in the on position (if fitted).
No
Is there power Make
at the external power
socket? available
Yes
Is fuse
Yes
at mains
plug OK?
No
Replace fuse in
mains plug
Put a jumper on
Replace
the room thermo-
the fuse
stat connection
No
Yes
Is there a jumper
on the room Is fuse
thermostat 0,6 A OK?
connection?
Yes
Check pump
connection
Fit correctly the
ignition electrode
Does the boiler
lock-out without
No
starting the
burner?
The gap between
ignition electrode
and hood
is correct?
Yes
Check for continu- No
Is there a spark
ity between ignition
at the ignition
electrode and igni-
electrode?
tion transformer
No
Is the gas
Check the
available?
gas supply
No
Check the
Is there voltage at
connection on
the gas valve?
the fan PCB
Replace the
gas valve
NOTE:
After completing fault finding reset the room thermostat (if fitted) to the required setting. If the appliance will not function check the wiring
to the clock and if necessary, replace the clock.
24
Yes
Does
the pump
start?
No
No
Is the clock in
the correct
band time?
Yes
No
Check the
time clock does
his contacts
open and close
when the clock
turns?
No
Yes
No
Yes
Is there voltage
available
to the pump?
No No
The boiler
lock-out
starting
the burner
Yes
Yes
reverse
polarity between
phase and neutral
Yes
Yes
Yes
Yes
Turn the clock Does
in the right the fan
position start?
No
Is there voltage
Replace
available
the clock
to the fan?
No
Yes
Make it free to Replace
rotate the fan
No
Check the
Is pump shaft
power supply
free to rotate?
cable
Yes
Replace
the pump
The ignition of the
burner is noisy
Yes
Check the settings
of the gas valve
and "POT. ACC."
trimmer
No
Does the boiler
remain in
pre-purge mode?
Yes
No
Is limit
Replace the
thermostat
limit thermostat
calling for heat?
Yes
Yes
Is the micro-switch Loose the screw
on the diverter on the flow
valve locked?
switch cover
No
Yes
Does the
micro-switch
Check the
operate correctly?
connections of:
limit thermostat
No
flow switch
in the PCB
Replace the
control board
microswitch
No
No
Does the fan
speed decrease
reducing the flow
thermistor
temperature
setting on
3) PCB control
the C.H. knob?
Yes
No
Does the
boiler switch
OFF before
achieving the
temperature?
Yes
satisfactory
and
Check:
2) C.H.
board
Boiler is