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8.2 Burner injectors
1. Carry out steps 1 to 6 of section 8.1.
2. Unscrew the main burner injectors.
3. Re-fit new injectors.
4. Re-assemble in reverse order.
8.3 Ignition system
To access the ignition system, follow steps 1 to 3 in
section 8.1.
Ignitor
-
refer to figure 9 and locate the ignitor (on
the side of the burner rack). Disconnect the wire,
remove the screw and the ignitor. Clean with an
emery cloth.
Note: Spark gap must be maintained to 3.0 mm (see
figure 10a)
Re-fit the ignitor as per figure 10b.
Due to high voltage on the spark wire and
electrode, do not touch when energized.
See hazard levels.
Flame sensor -
Refer to figure 9 and locate the
flame sensor. Disconnect the wire, remove the
screw and the flame sensor. Clean with an emery
cloth.
Ignition controller -
The enclosed integrated
circuit monitors the operation of the burner including
ignition. Do not attempt to dismantle the ignition
controller. Each heating season ignition cables
should be checked for insulation deterioration and
good connections.
Proper operation of the direct spark ignition
system requires a minimum flame current of 1,0
μ
A when measured with a micro-ammeter.
Fig. 10a - Ignitor assembly
Fig. 10b : Fitting the ignitor
For further information and checkout procedure of
the direct spark ignition system, refer to the
manufacturers control operating instructions a copy
of which is supplied with the air heater.
8.4 Multi-functional gas control valve
1. Ensure gas supply to the air heater is turned
OFF.
2. After the air circulation fan has stopped, switch
OFF the electricity supply to the air heater.
3. Mark for future identification and disconnect the
wires connected to the valve.
4. Disconnect the gas service union between the
control valve and the gas service tap. Remove
the gas control valve.
5. Re-fit a replacement valve making all of the
required
connections.
6 Carry out complete commissioning procedure
prior to placing the appliance back into service
as outlined in section 6.0
The gas control operating valve is the
prime safety shut-off.
All gas supply lines must be free of dirt,
scale, etc. before connecting to the air
heater thus ensuring positive closure of
the control valve.
8.5 Thermal overheat (limit) controls
If it is determined that the thermal overheat control
needs replacing, use only authorized replacements
that are designed for this appliance.
To gain access to the control, open the controls
compartment access door. Refer to figure 9 for
control locations. The control near the top of the air
heater is a disc type control. Both controls are
capillary types with a capillary tube that extends into
the heat exchanger area. To remove the controls,
disconnect the wires leading to them, remove the
fixing screws and lift clear of the inner casing panel.
Note
: The capillary control is fitted to a bracket.
With the bracket removed from the air heater,
remove the control from the bracket.
When replacing a capillary control be careful not to
damage the capillary tube by kinking. Make bends
with a generous radius (approx 25 mm).
8.6 Combustion air control/switch
If it is determined that the air differential pressure
switch needs replacing, use only authorized
replacements that are designed for the air heater
being serviced. These switches are calibrated to
operate at the designed combustion air flow duty for
each appliance size in the product range.
8.7 Combustion air fan (venter)
1. Ensure gas supply to the air heater is turned
OFF
2. After the air circulation fan has stopped, switch
OFF the electricity supply to the air heater.
3. To gain access to the fan open the hinged
controls compartment access door. refer to
figure 9 for location
4. Mark for future identification and disconnect the
wires connecting the fan motor at the terminals
on the main wiring junction.
5. Remove combustion air fan and clean as
necessary using a wire brush and solvent to
remove sticky residues.
6. Re-assemble and check for free rotation before
proceeding to test the appliance.
Note : the combustion air fan motor is lubricated for
life. DO NOT OIL or GREASE.
