Worcester Combi RSF 240 Installation And Servicing Instructions page 34

Can a pilot flame be observed?
YES
Does the main burner ignite?
YES
Does the gas pressure remain at 2.2
mbar for approximately two
minutes and then increase to the
set level over the next one minute?
Note.
The system load must be
greater than 9kW and in a cool
state for this to be possible.
YES
3 ___ __.
NO
..,._ Is there a gas supply to the
appliance?
NO
tYES
Is the pilot injector free from
blockage?
I
YES
Has gas supply been bled through
the system?
I YES
Replace the gas
valve.
NO
..,._ 1\.irn on the gas supply and check
the pressure.
NO
..,._ Replace the injector.
NO
..,._ Bleed the system.
NO NO
..,._ Has the spark electrode stopped
sparking?
..,._ Check the overall condition of the ..,._ Replace the sequence board.
YES
spark electrode. Is it in poor
condition?
+YES
Replace the spark electrode.
Is there a 240V supply at pin ML on
NO
terminal
CN4? ..,._
Replace the sequence board.
NO
-,I-Y-ES _ _ _ _ _
Check the gas supply to the
appliance and check the burner for
blockages. Is the gas flowing
correctly?
I YES
Replace the gas valve.
..,._ Does the DC voltage across the gas
valve Modureg terminals remain at
a constant low voltage for
approximately two minutes and
then gradually increase
over
the
next one minute?
Note.
The voltage
values are not important.
I YES
Replace the gas valve.
34
NO
..,._ Rectify the fault.
NO
..,._ Replace the main driver board .
l
If problem persists check earth
connections.