Igniter and Flame
Sensor Assembly (Spark)
■ The igniter and sensor assembly is located within a
metal enclosure mounted to the heat chamber above
the burner. See Fig. 15 for Model AD060 and Fig. 16
for models AD100 and AD250.
■ The igniter/sensor assembly may require cleaning
due to accumulations of dust and dirt over a period
of time, thereby affecting its ability to ignite fuel gas
and sense burner fl ame. Cleaning will require igniter/
sensor removal.
-- If spark appears to be weak, briskly rub the igniter
electrode with emery cloth or steel wool to remove any
buildup. Recycle the heater.
--- If the spark appears strong but the heater cycles off,
briskly rub the sensor rod with emery cloth or steel
wool to remove any build-up. Restart the heater.
■ Ensure the igniter gap is 1/8 -3/16 in. and the igniter
tip is positioned over the burner port according to the
illustration below. See Figs. 15 or 16 depending on
design.
FIG. 15
Flame Sensor
Igniter
3/16 in.
Burner
Loosen screws,
slide igniter up/
down to maintain
proper gap,
remove screws
as needed for
servicing igniter
assembly.
FIG. 16
To gap igniter loosen screw,
move enclosure up or down
to allow proper positioning of
igniter to burner.
To remove igniter/sensor with
enclosure remove screw, lift as-
sembly from its mounting slots
Igniter/sensor enclosure
Loosen screws and slide igniter
enclosure up or down to maintain
proper gap for servicing, remove the
screw and lift the enclosure from the
mounting slots in heat chamber.
Guardian with Smart Sense™
Heat
Chamber
Igniters/
Sensor
Enclosure
Remove
Screws
Burner
Sensor
Igniter
3/16 in.
Heat Chamber
Igniter Lead
Sensor Lead
Owner's Manual • Guardian
Transformer
■ The transformer supplies 24 volts to the ignition
controller to start the ignition process.
-- If 24 volts is not supplied from this transformer to
the ignition controller, the heater will not operate.
FIG. 17
21