Cabin Heater And Ventilator System; Heater Maintenance - Piper PA-24 Comanche Service Manual

10·1. General.
PIPER
COMA~CHE
SERVICE MASl'AL
SECTIO~
X
C\BI'\ HEATER A'\D
\·E~TIl.ATOR
SYSTEM
•
10-:!. Heat for the cabin of the Comanche is prov ided by a hot air exchanger installed on the ex haust muffler.
On the PA·14-IXO and PA·14·150. fresh air enters the engine compartment through the upper portion of
the nose cow ling. passes over the engine and is vented tothe heater muff through a flexible hose located on the
baffling at the rear of the engine. On the PA·24·260 and PA-24-400. air enters through the lower portion Ilf
nose cowl and is directed throuzh flexible hoses to the muffler shroud. The air is then heated and vented into
the cabin area through a
\ah~
which can be controlled from the instrument panel. When the valve
i~
completely closed off. the heated air is \ ented back into the engine compartment. The heater outlet in the cabin
is located at the top of the nose wheel housing on early PA-24-180 and PA·14-250 models and along each -ide
of the fuselaue on late PA-14·IXO and PA-14-150 models as well as all PA-14-2hO and
PA":~4-4()()
aircraft.
Control for the heater system is located on the right panel. below the instruments. The windshield is kept clear
of frost. ice. etc, by a defroster system which operates from the heater muff. but has an individual control.
Fresh air for
ea
rly PA-14-ltolO and PA-14-150 models is supplied to the cabin by adjustable
ventilator-,
located be-ide each seat. and one larger ventilator located under the instrument panel on the lett ...ide of the
cabin.
For the late PA-24-IXO and PA-24-250 aircraft. fresh air is supplied by ventilators located be-ide each
seat and an air intake located at the top of the fuselage. directing air through individual overhead outlets.
On the PA-14-2hO and PA-24-400. fresh air for the cabin interior is picked up from
two
air inlet.'
the
leading edge of each wing. The air passes through the wings to the wing root area and is discharged i
the cabin ncar the
nOM ,iu~t
forward of the front seats. In addition. two fresh air scoops are located on t
dorsal fin. The . . . c prm ide air for two overhead ventilators in the rear seat area and two front seat ventilator-
located between the \\ indshield posts and the instrument panel.
I()-~.
Heater :\1aintenance. If the exhaust manifold should become defective. carbon monoxide fumes max
be discharged into the cabin area. therefore it is imperative that the exhaust manifold be inspected regularly.
The heater muff must be removed in order to inspect the manifold assembly. Check the operation of the
push-pull controls to insure the
valve
doors function properly. When the controls are pulled out the door
should be completely open to permit full air flow. When the controls are pushed in. the valves should close
off all air pas... age and vent the air into the engine compartment. Refer to figures
10-1
through 10-5 for an
illustration of the heater system.
ISSt'ED: 8/18/72
3F8
CABI~
HEATER
A.
VE!"TILATOR
SYSTE\1