Worcester 350 Combi User Manual

Does the f an start up at high speed ?
(l'o check t his it m ay be necessary to NO
measure the vo lt a ge acros s the fan ---..
terminals . This sho ul d be 240V AC
for two sec on ds . Gas mu st be turned
off d uring this test.)
YES
NO
NO
Rep la ce fuse F2 .If it blows again
replace th e ignition b oard .
D
oes the fan start up at l ow speed ---.. Is there an y AC voltage across the
on ly? fan te rm i nal s?
--~-------------
YES
YES
YES
~ Is there a live supply to the grey pin
of terminal X8 ?
NO
NO
NO
---.. Is there a li ve supply to the
green pin of term i nal X21 ?
YES
Replace the driver b oard assemb ly . ~ Monitor the pink pin on terminal XS Free th e fa n if it is stuck or replace Is there a live supply to the
and restart the appliance again . the fan . white pin of terminal X2 11
Replace the ig n ition board.
J
r---- Does the voltage ever reach 36V DC? I I
YES .-----------__.NO YES
J NO I
Check the suppl y tu bes to the air Replace the domestic hot water sensor ~ Remove the Mo l ex pl ug from terminal
NO
pressure switch for co rrect ro u ting l X13 .1s there a resistance of 15 to 2.5
and condition Has damage occurred ? kohms across the two black pins ?
r--__,;~--------' YES l
YES i
Re pl ace the i gn ition board.
~ Is there SV DC on the ora n ge p in of Replace the transformer. ~ Remove the Mo l ex plug from
----------------- rerminal ~ '
---------- ------- terminal X2 .1s there an open circuit
YES
-- - --- - ..... ...,_ _ _.1 YES
Is th er e less tha n 2V DC on the red • •
NO
pi n of te rm inal XS ?
NO YES
Replace the air pr essure switch . Repair the fault.
NO YES
Rep la ce the driver board assembly. ~ Is th ere 39V DC on the or ange pin of ---.. Replace the ig n ition board .
termi n al X8 ?
NO NO NO
Is t he cen tr al heating pump pulsed ---..
on for app roximately two seconds?
YES
YES
For fa ul ts during the r emaining start · ~
up i gn i tio n r efe r to FAILURE AT
POINT D, E, FOR G in the central
heating test se cti o n.
5 ----
Restart the hot water cycle. D oes the ---.. Restart the domestic hot water ____...
b rown pin of term i nal X19 ever cycl e. D oes the white pin of terminal
r eceive a live supply f or X8 ever drop to zero V DC for
approxirna rely two seco n ds' approximately two seconds '
NO
1 YES
YES
Remove the plated screw in the ---.. Rep l ace the central heating pump.
ce n tre of the central heating pu mp
an d tum the sh aft with a flat bladed
screwdriver . Can the cen tr al heati ng
p
ump now be pulsed?
39
between th e brown and blue wires or
between the or an ge and black wires ?
NO
Replace the driver board assembly .
Replace the driver board assembly .
1
Replace the ignition board .

Worcester 350 Combi Specifications

General

Brand	Worcester
Model	350 Combi
Category	Boiler
Language	English