Piper Navajo Chieftain PA-31-350 Service Manual page 818

NAVAJO CHIEFTAIN SERVICE MANUAL
TABLE XIII-I. TROUBLESHOOTING CHART (HEATING SYSTEM) (cont.)
Trouble
Cause Remedy
Heater fires but
bums unsteadily.
(cont.)
Inoperative ignition
assembly.
If vibrator is in good
condition, replace ig-
nition assembly only.
Restriction in fuel
nozzle orifice.
Nozzle loose in retain-
er or improper spray
angle.
Remove nozzle for
cleaning or replace-
ment.
Tighten or replace the
nozzle as required.
Heater starts then
goes out.
Lack of fuel at heater.
Check fuel supply
through all components
from the tank to the
heater. Make nec-
essary corrections.
Inoperative or chat-
tering combustion air
pressure switch.
Inoperative overheat
switch.
Inoperative cycling
switch.
Low voltage.
Adjust or replace
switch.
Replace switch.
Adjust or replace the
switch.
Attach external power.
I
Heater fails to shut
off.
Fuel solenoid valve in
heater stuck open.
Remove and replace
solenoid assembly.
Inoperative duct and
cycling switch.
Defective heater
switch.
4D2
Check and repair
Replace the heater
switch.
HEATING AND VENTILATING SYSTEM
Revised: 10/15/82