Routine Cleaning And Inspection - Worcester WM 12 Installation And Servicing Instructions

14. Routine Cleaning and Inspection

WARNING: The appliance is serviced and repaired externally.
External equipment operated at 230volts should not be ser-
viced or repaired under adverse weather conditions.
14.1 The following should be carried out at least once per year
to ensure efficient, trouble free operation.
NOTE: The service engineer should have access to the property to
check for system faults and reset/replace electrical safety devices.
NOTE: The service engineer should take any necessary precau-
tions to protect him/herself and any third party against hot sur-
faces on the appliance.
1. Carry out a pre-service check noting any operational faults.
2. Check and clean the burner.
3. Checkand clean the air intake inlets around the external cover and duct.
4. Check that the flue system is unobstructed and clean as necessary.
5. Check and clean the insulated box.
6. Check and clean the baffle.
7. Check and clean the heat exchanger surface.
8. If the appliance has been installed in a compartment check
that the ventilation areas are clear.
9. Clean all oil filters.
Some of the servicing points are covered more fully in the following
instructions:-
14.2 Pre-Service Check
1. Remove the internal cabinet as described in Section 5.
2. Remove the external cover and switch the service switch to
the 'OFF' position (mid position) (see fig. 29).
3. Switch the service switch to the 'RUN' position (fully black)
(see fig. 29) to operate the appliance and system, noting any
faults which may need to be corrected during the service.
4. To override the programmer switch the service switch to the
service mode (fully red) (see fig. 29 and Section 10.11).
14.3 Cleaning the Burner
IMPORTANT – Disconnect the electrical supply at the mains
before commencing any servicing. Remove the burner electrical
plug lead by depressing the two locking ears and pulling the
plug downwards. Turn off the oil at the service cock.
1. Remove the burner.
(a) Isolate the oil supply at both the oil tank and the isolating
valve between the burner and oil filter.
(b) Remove the burner electrical plug lead by depressing the two
locking ears and pulling the plug downwards.
(c) 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.
(d) Hang the burner on the burner hanging bracket situated on
the bottom left hand side of the external duct (see fig. 30).
2. Clean the fan impeller using the following procedure:
Electro-oil Inter B9 Burner
(a) Remove the two screws holding the combustion head in posi-
tion and withdraw the combustion head.
(b) Remove the three remaining screws holding the front cover
plate in position and withdraw the cover to expose the fan impeller.
(c) Clean both sides of the fan impeller and remove any debris
from the burner housing.
(d) Check the impeller rotates freely.
(e) Clean the air inlet passage and check that the adjustment
mechanism operates freely.
(f) Re-assemble the components.
5. Remove the combustion head and thoroughly clean all
deposits.
6. Inspection of the Mechanical Shut-off Valve (See Fig. 31)
(a) Remove the nozzle.
(b) Fasten an M5 screw, with a minimum length of 30mm, into
the threaded hole (A) and pull the screw to withdraw the check valve.
(c) Check the nozzle holder is clear of any debris and clean if necessary.
(d) Check the three holes in the check valve are clear of any
debris. Discard the check valve if the holes cannot be cleared or
if the unit is defective and replace with a new one.
(e) Reassemble in reverse order.
7. It is strongly recommended that the oil atomising nozzle be
replaced at each service. If this is not possible then remove and
clean the integral filter, but under no circumstances should the
nozzle be stripped into its component parts and never attempt
to clean the nozzle tip.
8. Check and reset the electrodes, where necessary, as shown in fig. 28.
9. Replace the combustion head and check that the nozzle lies
central to the combustion head and the head settings are as
shown in fig. 28.
10. Withdraw the photocell from its housing and clean.
11. Remove and clean the oil pump internal filter using kerosene
or white spirit. The internal filter is accessed by removing the oil
pump cover on the Suntec AS47C and by unscrewing and with-
drawing the cartridge on the Danfoss BFP 41 as indicated in fig. 10.
12. It is recommended that the standard flexible oil lines are
replaced at each yearly service to prevent the possibility of a
leak due to ageing.
13. Re-assemble the burner components.
14. Check the sponge O-shaped gasket located around the com-
bustion head and replace if necessary. It is imperative that this
seal is in good condition since failure will cause the combustion
gases to be re-circulated into the burner inlet.
14.4 Remove the paper element from the external oil filter and
replace. If the filter contains a washable element then thoroughly
clean in Kerosene or white spirit and re-assemble into the filter.
14.5 Clean the Boiler.
NOTE: An electrical service lead can be fitted to the external con-
trol box enabling the service engineer to use a light or vacuum
cleaner. The electrical service lead is available from Worcester,
Bosch Group as an optional extra, Part Number 7 716 192 301.
1. Remove the telescopic flue by releasing the two wing nuts
and washers, check and clean.
2. Check the condition of the seals on both the inlet and outlet of
the flue system and replace if necessary.
3. Remove the insulation box by releasing 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 underneath and remove.
Care must be taken when the insulation box is removed so as not to
cause damage to the insulating material or the external duct.
4. Check the insulation box for any visible defects and replace if
necessary.
5. Check the three rope seals as shown in fig. 27 and replace if
necessary.
6. Vacuum the inside if the insulation box being careful not to
damage the surface of the insulation.
NOTE: When cleaning the inside of the insulation box it is
imperative that the surface of the insulation is not damaged,
therefore, do not use abrasive tools or cleaning fluids on this
component.
7. Remove the baffle, clean and check its condition. Replace baf-
fle if considered to be badly corroded.
8. Thoroughly clean all of the heat exchanger surfaces using a
stiff wire brush and vacuum clean all loose debris from the com-
bustion chamber.
9. Replace the items in reverse order noting the baffle position
shown in fig. 26.
14.7 Fire Valve.
Check that a fire valve is fitted to the incoming oil line with the
body located at a minimum distance of 1 metre away from the
appliance and the detection element is located within the exter-
nal duct next to the burner. Two inline fire valve clips are provided
28