Worcester C1

34
Red diode is
damaged. Replace
control board.
(Section 15.4.10)
Is there a link at
terminal ST13 pins 1
and 2?
Is there an electronic
programmer at
position ST5 at right-
hand end of board?
Replace control board.
(Section 15.4.10).
With CH control knob
fully clockwise, does
the boiler ignite and
appear to run
normally in central
heating mode?
Is there 230V AC
across terminal ST8
pins LR and N?
There is no heat
demand. Check room
thermostat or mains
programmer (or link).
Insert a link
FAIL POINT D
No No
No
No
No
Yes
Yes
Remove programmer
connector from board
edge. Does CH lamp
now light?
Yes
Correctly set or
replace electronic
programmer.
Yes
Yes
Red diode is
damaged. Replace
control board.
(Section 15.4.10)
Replace control board.
(Section 15.4.10).
With a hot water tap
fully open, does the
boiler ignite and
appear to run
normally in hot water
mode?
Remove multiway
connector from board
position ST16. With
tap still open is there
continuity across
contacts 19 and 20
(2 pink wires)?
Locate and observe the
flowswitch assembly
(behind the air pressure
switch). Does the lever
above the microswitch
move up and down with
the demands, thus
activating and
de-activating the
microswitch?
FAIL POINT E
No No
No
Yes Yes
Yes
Replace flowswitch
assembly
Check or replace
wiring or microswitch