29
4000116705-2
17 Routine Cleaning and Inspection
17.8 Burner, refer to diagram 17.3.
• Undo main gas supply nut from under the sealed chamber.
Note: The washer between main burner and main burner gas
supply must be kept for use on reassembly.
• Pull off ignition leads from ignition unit.
• Pull off flame sense lead from flame sense electrode.
• Unscrew and remove burner support bracket securing screw
and remove bracket.
• Remove burner from boiler by lifting up and pulling forwards
easing the leads through the grommet, taking care not to
damage insulation.
• Clean burner by washing in soapy water. Dry thoroughly
before refitting.
• When refitting burner ensure that rear of burner locates into
location slot and the injector locates correctly through the
grommet.
Note: To gain access to injectors for removal, refer to
Section,
20.24 in Replacement of Parts
.
9341
Diagram 17.3
11755
9345
MAIN GAS
SUPPLY NUT
GROMMET
BURNER
SUPPORT
BRACKET
BURNER
LOCATION
SLOT
FLAME
SENSE
LEAD
IGNITION
LEADS
11756
17.9 Heat exchanger, refer to diagram 17.4.
• Disconnect electrical connections from fan.
• Unscrew and remove two fan retaining screws from the right
hand side edge of fan mounting plate.
• Remove fan with mounting plate attached by pulling forward
and out of boiler.
• Remove air pressure switch sensing tube at rear of flue hood.
• From front of boiler carefully unclip wire spring retainers from
side of flue hood.
• Remove the overheat thermostat by unclipping from the
heating return pipe.
• Lift flue hood clear of heat exchanger and examine for debris.
• Using a soft brush or vacuum clean as required.
DO NOT USE ANY TOOL LIKELY TO DAMAGE PAINTED
FINISH OF HEAT EXCHANGER.
Note: When re-fitting fan, make sure that the two lugs on the fan
mounting plate engage in the flue hood
11757
Diagram 17.4
11760
11759
AIR PRESSURE SWITCH
SENSING TUBE
WIRE SPRING
RETAINER
2 OFF
FAN
RETAINING
SLOTS
OVERHEAT
THERMOSTAT
➜
11758
