Piper SEMINOLE PA-44-180, Maintenance Manual

Page: 127 / 881

7. Disconnect the fuel and water drains from the bottom of the heater and allow them to slide down.
8. Disconnect the combustion air blower inlet hose from the blower assembly by removing the cotter key
and clevis pin at the blower.
9. Loosen the clamps from around the heater and remove the heater from the airplane. The exhaust shroud
should remain in the airplane.
10. With the heater removed, the necessary maintenance may be performed as required.
INSTALLATION OF HEATER. (Refer to Figure 21-2)
1. Ascertain that all the heater components are on the heater. Position the exhaust tube shroud on the tube
mounting flange located in the nose section.
2. Position the heater over its mounting brackets and ascertain that the exhaust tube extends into the exhaust
shroud. Lower the heater to its mounting brackets. The exhaust tube should extend out the bottom of the
nose section.
3. Move the heater slightly to obtain the best fit of the exhaust tube shroud and heater. Place the heater
clamps around the heater and mounting bracket flanges and secure.
4. Connect the combustion air blower inlet hose to the combustion air blower assembly on the heater and
secure in place with the clevis pin and cotter key.
5. Connect the fuel and water drain lines to the bottom of the heater.
6. Connect the fuel supply line to the heater and cover over the fuel shroud and secure with two screws.
7. Attach the intake valve control cable to the intake valve and install the clamp.
8. Connect the electrical leads to the heater terminal block on the heater as shown in figure 21-2.
9. Check the operation of the heater.
10. Lift the nose cone up and secure with appropriate screws.
HEATER ELECTRICAL SYSTEM CHECKS.
ELECTRICAL CHECKS.
These tests are listed as an aid in isolating open circuited or inoperative components.
— Note —
The schematic wiring diagram (Figures 21-7, 21-8 and 21-9) shows, in addition to the
heater circuitry, the aircraft control circuit. For the purposes of this manual, the
circuitry shown in these illustrations will be utilized to describe voltage checks.
It must be assumed that power, which is furnished through the heater circuit breaker is present at the HEATER
SWITCH at all times. Always check the circuit breaker before performing voltage checks.
PA - 4 4 - 1 8 0 / 1 8 0 T
AIRPLANE MAINTENANCE MANUAL
2 1 - 4 3 - 0 7
Page 21-16
Revised: May 15, 1989
1F7
PIPER AIRCRAFT