Installation - Worcester WM 12 Installation And Servicing Instructions

11. Installation

The Wall Mounted appliance is installed within the wall of the
property and is serviced from outside the property, but the engi-
neer must have access to inside of the property when servicing
the appliance.
The appliance must be installed on a load bearing external wall with a
wall thickness ranging from 102 mm (4 inches ) to 460 mm (18 inches).
It is recommended the appliance should only be installed where
outside the property the maximum height from the bottom of
the appliance is 1.5 metres above a suitable hard standing from
which servicing and maintenance can be safely carried out.
WARNING: The appliance is serviced and repaired externally.
External equipment operated at 230volts should not be ser-
viced or repaired under adverse weather conditions.
11.1 After unpacking the appliance it is recommended it is disas-
sembled in the following order ensuring all parts are stored in a
safe place. Refer to figs. 2 and 3.
1. Remove the white cabinet, as described in Section 5, and store
in a safe place to avoid damage during installation and to allow
easy inspection for any leaks after the system has been filled.
2. Remove the external cover by undoing the two fixings under-
neath, then pull the bottom of the cover so it clears the bottom of
the external duct/flue, lift up to release the two locating tabs
from top of the duct and store in a safe place.
3. Remove the telescopic flue by undoing the two wing nuts and
washers holding the flue to the insulation box and store in a safe place.
4. Remove the burner electrical plug lead from the external control box
by depressing the two locking ears and pulling the plug downwards.
5. Remove the burner from the boiler by slackening the 5 mm
retaining screw located to the left of the burner control box. This
will require the use of a 4 mm hexagon driver. See fig. 3.
6. The insulation box is removed by undoing the four M8 wing
nuts and washers. Holding the burner mounting flange, pull the
insulation box out far enough until you can get a hand under-
neath, remove and store in a safe place. Care must be taken
when the insulation box is removed, not to cause damage to the
insulating material or the external duct.
7. Remove the baffle by lifting slightly to clear the baffle retainer
and pulling forward.
8.Central Heating Control and Automatic High Limit
Thermostats (See fig. 2)
Remove the split pin from the thermostat phial pocket located in
the front, right hand side of the boiler. Carefully withdraw the
control and automatic high limit thermostats from the pocket
noting their positions.
9. Manual Reset overheat, Manual Reset Duct and Frost
Thermostats (See fig. 2)
Carefully lift the phial retaining springs so the thermostats can be
pulled out from the springs noting their positions.
10. Place cloth or cardboard underneath the heat exhanger
inside the external duct to prevent damage to the surface of the
duct when removing the heat exchanger. Remove three of the
four M6 nuts/washers leaving only the bottom left nut and
washer in place. Pushing on the bottom of the heat exchanger
remove the remaining nut and washer. Slowly release the heat-
exchanger allowing it to hang on the top two mounting studs.
Remove the heat exchanger by lifting upwards to release from
the two mounting studs. Place the heatexhanger on it's back
taking care not to damage the threaded studs.
11. Undo the two screws on the external control box. Pull down
the service switch assembly taking care not damage the wiring.
Pull off the earth spade connector that is connected to the exter-
nal control box at the service switch end.
12. Remove the two 'D' shaped grommets from the back of the
external control box and wall mounting duct (See fig. 25).
13. Remove the internal control box by undoing the two screws
holding the facia to the internal control box and pivot the facia down.
14. There is an earth loom that connects the internal control box
to the wall mounting duct, release the wire from the earth rivet
inside the internal control box and push back through the hole in
the back of the internal control box.
15. Undo the two remaining screws holding the internal control
box to the boiler. Carefully pull the internal control box out of
the appliance and store in a safe place.
16. Remove the external duct from the wall mounting duct and
store in a safe place.
17. Remove the Wall Mounting duct from the pallet by undoing
the nuts and bolts holding it to the pallet. The two transit ties can
be removed or turned so that they are in the vertical position
next to the wall mounting duct to allow installation of the duct.
11.2 Mounting of the Wall Mounting Duct
There are two possible options:
(a) Align the internal cabinet with existing room units or features.
(b) Align the duct with the external brick courses.
1. Hold the wall mounting template up on the inside wall to the
desired position. The cabinet outline is shown by the dotted line.
When the position is correct tape the template to the wall.
2. At the pilot hole position on the template drill through to the
outside wall. Measure the position from the centre of the pilot
hole 191 mm above and below, to indicate the duct position
and mark on the outside wall.
If using method (a) go to 11.2.5
If using method (b) proceed as follows:
3 If the edge of the duct position does not align itself with the
mortar move the bottom edge of the duct up or down depending
which is the most desired position with reference to the position
of the appliance on the inside wall.
4. Measure 382 mm from the bottom edge to the top edge of the duct
position. Check to see if this aligns with the mortar and make any
adjustments that may be required. Go inside the property and adjust
the template position by the amount it has been adjusted outside.
5. Draw a line for the top and bottom edge on the external wall
and then measure 191 mm from the pilot hole to the left and
right to indicate the side positions.
There should now be a square profile of 382 by 382 mm. Add 5
to 10 mm around the edge of the profile to allow enough clear-
ance to insert the duct.
6. Inside the property with the template in position mark the
mounting bracket hole positions. There are two possible posi-
tions for each screw use the outside position (A) if possible.
7. Mark out the duct position on the inside wall. There should
now be a square profile of 382 by 382 mm. Add 5 to 10 mm around
the edge of the profile to allow enough clearance to insert the duct.
8. Using a 10mm drill bit, drill the 4 holes required for mounting
the wall mounting duct. There are two possible positions for each
screw use the outside position (A) if possible.
9. Cut the hole in the wall.
10 The Wall mounting brackets are mounted to the duct in the
standard 315mm position so the internal cabinet will be flush with
a 300 mm deep kitchen unit; as shown in fig. 24a. If the household-
er requires the appliance to be installed within a 300 mm kitchen
unit the M6 nuts and washers must be removed from the studs
holding the wall mounting brackets to the wall mounting duct.
Reassemble in the optional 285mm position as shown in fig. 24b.
11 Mount the wall mounting duct to the wall using the raw plugs
and screws provided.
12 Check the that the wall mounting duct is level using a spirit
level from front to back and left to right. Adjust as necessary so
that the duct is level.
NOTE: It is important the wall mounting duct is level or slop-
ing slightly downwards towards the outside of the property.
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