Worcester Highflow 400 RSF Installation And Servicing Instructions page 51

NO
Does the fan run?
YES
NO
Does sparking occur?
Note: If the appliance is
very cold, sparking may
be delayed because of
poor acceleration of the
fan
YES
YES
POINT
D
NO
Is there 230V at
pin 1 of
terminal X16?
(Left black wire)
YES
NO
Is there 230V at
pin 2 of
terminal X8?
(Left orange wire)
YES
Is there 230V at
NO
pin 1 of
terminal X6?
(Brown wire)
YES
NO
Is there 230V at
pin L of
terminal CN1 on the
ignition board?
(Brown wire)
YES
Is there 230V at
NO
pin L2 of
terminal CN2?
(White wire)
YES
Is there 230V at
NO
pin L3 of
terminal CN2?
(Brown wire)
YES
Gain access to the
fan. Is there 230V
NO
across the fan
terminals?
(Brown and
yellow wires)
YES
Replace the fan
Is there a 230V
NO
supply at pin L1 at
terminal CN2?
(Grey wire)
YES
NO
Check for faults on
the electrode lead
and electrode and
repair as necessary.
Does sparking
occur?
51
NO
Is there 230V at
pin 2 of
terminal X16?
(Right black wire)
YES
Hot water high limit stat has tripped.
Investigate cause of overheating
and/or replace
NO
Is there 230V at
pin 1 of
terminal X8?
(Right orange wire)
YES
Safety limit stat has tripped. Investigate cause of
overheating and/or replace
Replace the
control board
Fault with
interboard wiring.
Repair or replace
Replace the
ignition board
Replace the air
pressure switch
Check harness and
repair or replace
Check and replace
the air sensing
tubes or replace
the air pressure
switch
Replace the Ignition
board
Replace the
control board
Replace the
control board