Piper AZTEC D PA-23-250 Owner's Handbook Manual page 37

SECTION II THE PIPER AZTEC ''D''
additional cold air to the front ·seat through a vent on the bulkhead.
Cabin air enters the heater system through an inlet above
the landing light, and when the heater is not . in operation, the
inlet can serve as a source for cool air by pulling out the heater
controls.
A 35,000 B.T.U. Janitrol heater installed in the nose section
furnishes a source of. hot air for cabin heating and windshield
defrosting.
Operation of the heater is controlled by a three position
switch located on the right side of the instrument panel, labeled
"FAN'', "OFF" and "HEAT". The "FAN" position will op-
erate the vent blower only and may be used for cabin ventilation
on the ground or windshield defogging when heat is not desired.
For heat the manual heater fuel valve located on the fuel
selectcx panel must be on and the three position switch turned
to "HEAT". This will start fuel flow and ignite the burner
simultaneously. With instant starting and no need for priming,
heat should be felt within a few seconds.
Regulation of heat, airflow and defroster operation is con-
trolled by the push-pull knobs on the cabin air control panel.
The middle knob is connected to an adjustable thermostat which
makes it possible to select a desired temperature of heated air
through a wide range.
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Heating And Vent Controls
27
Cabin temperature and air
circulation can be maintained·
by using various combinations
of knob settings, to suit indi-
vidual desires. To minimize
the feeling of drafts, a low
air flow-high heat combination
should be used.
Windshield defrosting may
be regulated by various set-
tings of the defroster knob
and in severe windshield fog-
ging or icing conditions, it
may be desirable to restrict
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