Worcester Highflow 400 RSF Installation And Servicing Instructions page 52

NO
Can a pilot flame
be seen?
YES
NO
Does the main
burner ignite?
YES
NO
Does the burner instantly
operate at or near
maximum gas pressure?
YES
POINT
G
NO
Is there a gas supply
to the appliance?
YES
NO
Is the pilot injector free
from blockage?
YES
Replace the
gas valve
NO
Has the sparking
stopped?
YES
NO
Is there 230V at
pin ML of
terminal CN4?
(Brown wire)
YES
Check the gas supply to the appliance.
Check for blockages to the burner or
replace the gas valve
NO
Is there 230V at pin
1 of
terminal X4?
(Brown wire)
YES
Replace the gas valve.
If the problem is not solved, replace cable
to gas valve centre solenoid
52
Turn on the gas supply,
bleed the system and
check the pressure
Replace the
injector
NO
Live and Neutral
supply could be
reversed.
Check connections
to both boards
and electrical spur.
Is it correct?
YES
Check condition of
NO
spark electrode and
lead.
Is it poor?
YES
Replace as
necessary
Replace the
Ignition Board
Replace the
control board
Rectify
incorrect
wiring
Replace the
Ignition board.
If problem
persists, check
earth
connections