Piper Navajo PA-31 Service Manual page 921

C458
TO LANDING GEAR
VENT AIR
LANDING
GEAR RADIO NOISE
"—C1_
SWITCH
Figure 13-12. Wiring Schematic, B39D59, D39D59, Heater System
13-14 OPERATING PROCEDURE.
(Refer to Figures 13-10, 13-11 or 13-12)
a. Place the HEATER SWITCH in the ON (or HEAT) position. The ventilating air and combustion
air blowers should operate.
b.
The heater will ignite and continue to operate.
c. The DUCT SWITCH can be set to regulate the cabin temperature for desired comfort level. If this
ram air will increase the ventilating airflow and the heater output. On 39D59 heater system NO.
2, B39D59
and D39D59 heater system, an override micro switch is incorporated on the duct switch to override the
duct
stat at the very last movement of the duct stat arm toward the high position.
d.
To stop heater operation, turn off the HEATER SWITCH.
e.
It is desirable to operate the fan several minutes to cool the heater after operation. To stop
fan
operation, turn OFF the HEATER SWITCH.
13-15. INSPECTION OF HEATER AND HEATER COMPONENTS.
a.
Inspect all fuel lines and fittings for fuel stains, indicating leakage, and replace lines or tighten
fittings as necessary. (Refer to the latest revision of Piper Service Bulletin No. 641 for Heater Fuel Hose
Modification.)
b. Check heater for cracks, loose bolts, screws and wiring.
c. Inspect all electrical connections for corrosion. If corrosion is evident, clean affected
components, and wipe clean with a lightly oiled cloth.
Revised: 1/29/82
HEATING AND VENTILATING SYSTEM
PIPER NAVAJO SERVICE MANUAL
5B15