Worcester 350 Combi User Manual

Fig. 40. Facia (rear view in drop-down position).
S ealed system pressure gauge
Cap ill ary.
g
-
-
Operati ng Swit ch.
Indicato r lights.
Pressure gauge f ix i ng nuts.
Operating Swit ch mounting panel fixing nuts.
Fit a new board in the reverse order. The plugs are individually
matched and connections must not be forced. See Fig . 9b .
Set
the central heating pressure as described in Section 11 .5.
20. Ignition Board. See Fig . 9b .
Check that the electrical supp ly has been turned off.
Remove the facia. See Section 14.2 (
a) .
Carefully unplug or unscrew all the connections to the board.
Release the board from the clips securing it to the control box.
Fit a
new board in the reverse order. The plugs are individually
matched and connections must not be forced. See Fig. 9b.
21. Transformer. See Fig. 9b.
Check that the electrical supply has been turned off.
Remove the facia and lower
the control box. See Section 14.2 (a)
and 14.2 (b).
Unplug the connection to th e main driver board. See Fig . 9b.
Unscrew
the screws securing t he transformer to th e control box .
Remove the transformer.
Fit a new transformer ensuring
that the insulation pad is refitted
beneath the transformer.
22 . System Pressure Gauge. See Figs. 24 and 40.
Remove the facia and lower the control box. See Section 14.2 (a)
and(b) .
Drain
the heating c ir cuit as described in Section 14.3 (a) .
Remove the pressure relief valve
as described in Paragraph 11 pre·
ceding. Unscrew the capillary from the manifold.
Unscrew
the nuts and remove the pressure gauge and capillary
from
the facia. See Fig. 40.
Fi t a new gauge and capillary in the reverse order.
Open the valves, fill and re·pressurise the system as described in
Section
11 .2.
23. Central Heating Temperature Control Potentiometer.
See Figs. 20 and 40.
Check
that the electrical supply has been turned off.
Remove the facia. See Section 14.2 (a) .
Remove
the control knob by grasping it firmly and pulling it off
the spindle. See Fig . 20. Disconnect the plug from the main driver
board. See
Fig. 9b.
Unscrew
the l ocknut securing the potentiometer at the spindle
and withdraw. Fit the new potentiometer in the reverse order.
Reconnect the plug
to the driver board.
24. Operating Switch. See Fig . 20.
Check
that the electrical supply has been turned off.
Cen tral hea ting tempera tur e control potent i ometer.
27
Remove the facia. See Section 14 .2 ( a).
Remove the leads from the rear of th e switch, taking note of their
po sitions. See Fig. 20. Squeeze together the tw o plastic retaining
lugs
and remove the switch from the front of the facia.
Snap in the replacement switch and reconnect the leads. See Fig.9b.
25. Neon Indicator Lights. See Figs. 9b , 40 , 42, and 43
Check that the electrical supp ly has been turned off.
Remove the facia. See Section 14 .2 ( a).
Unplug the appropriate neon connection at the driver board. Con -
nect io n X3 or X6. See F ig. 9b.
Use an electrical screwdriver to carefu ll y push down through the
locking clip slot to depress the locking clips and withdraw the
leads of the failed neon . See Fig. 42. Remove t he neon from the
facia.
Push
the replacement neon in to the facia openi ng . See Fig. 9b.
Fig. 41 . Domestic hot water control
assembly.

Worcester 350 Combi Specifications

General

Brand	Worcester
Model	350 Combi
Category	Boiler
Language	English