Grant Spira Series - Burner Components

Boiler Servicing
57
!
NOTE
After a period of time in use, the
semi circular end wall of the brazier
hood may distort or show minor
cracks. This does not affect the
operation of the burner. The hood
should only be changed if there is
considerably deterioration.
• Open the brazier manually by
operating the release switch on the
servo motor and carefully pulling on
the end wall of the brazier.
• To operate the switch and release
the motor, either press and hold
down the switch down or lift and
hold the switch up – depending on
motor type used.
Refer to Figure 11-12.
Failure to operate the servo motor
release switch WILL result in damage
to the servo motor gears.
With the brazier open, dismantle the
brazier to thoroughly clean all parts as
follows, referring to Figure 13-2:
• Unscrew and remove the upper two
M6 nuts and washers on either side
of the brazier chassis, securing the
two brazier flame plates.
• Remove the four M6 screws from
the inside of the brazier.
• Unscrew and remove the two M6
screws securing the photocell back
plate to the burner.
• Remove both the two brazier flame
plates and photocell back plate
from brazier.
• Unscrew and remove the two M6
nuts and washers on either side of
the brazier chassis securing the
3-sided grate enclosure.
• Remove the four M6 screws from
inside the brazier and remove the
grate enclosure.
• Unscrew and remove the two M6
screws and washers (one each side
of the brazier chassis) securing the
ignition element mounting plate, and
remove it from the brazier chassis.
• From below the burner, unscrew
and remove the single cap screw
attaching the push rod of the
moveable brazier base to the shaft
of the servo motor.
• Disengage the push rod from the
motor shaft and remove brazier base
assembly from the brazier chassis.
Inspect all components for distortion or
damage and replace if necessary.
Clean all ash and clinker deposits from
all surfaces (in particular the upper
surface of the brazier chassis and the
underside of the brazier base assembly)
using wire bush and, where necessary,
a flat scraper.
Ensure that all air holes are clear.
Reassemble the brazier using the
following procedure:
• Fit the moveable brazier base
assembly to the burner and
reconnect the pushrod to the motor
shaft using the cap screw.
• Whilst operating the servo motor
release switch, push the brazier
base assembly fully back into the
brazier chassis.
• Insert the brazier clearance gauge
plate (supplied with the boiler)
between the brazier chassis and
brazier base assembly. Refer to
Figure 11-13.
• The clearance gauge should slide in
using manual force only. DO NOT
FORCE THE GAUGE INTO THE
BRAZIER!
• Reassemble the remainder of the
brazier, using the reverse of the
dismantling procedure.
• Leave all screws loose until all
components (excluding the burner
hood) are assembled correctly.
• BEFORE fitting the burner hood,
tighten the two screws securing the
photocell back plate to the front of
the burner.
• Fit the burner hood and then finally
tighten all remaining burner fixings.
• Remove brazier clearance gauge
from burner brazier.
• Operate servo motor release switch
and manually open and close
brazier to check it is free to move.
11.8 Burner Components
Check the burner fan inlet is clear of
debris.
If there is a build-up of debris remove
the burner fan and clean the fan blades
and fan housing. Refer to Figure 11-14.
11.8.1 Burner Fan
Check the burner fan inlet is clear of
debris. If there is a build-up of debris
remove the burner fan and clean the
fan blades and fan housing. Refer to
Figure 11-14.
Figure 11-13: Manual opening of
brazier
Figure 11-14: Fitting brazier clearance
gauge
DO NOT ATTEMPT TO FORCE THE
BRAZIER OPEN WITHOUT
OPERATING THE SERVO MOTOR
REALEASE SWITCH.
!
WARNING
Figure 11-15: Interior of burner
enclosure