TM9-4120-398-14
4-26. THERMOSTAT
This task Covers
a. Inspection
b. Test
C. Replacement
INITIAL SETUP
Equipment Condition
Tools
Power OFF
Tool kit refrigeration SVC
External control panel removed
Condenser access door open
Flexible ducts removed
Evaporator access panel removed
Control board panel removed
General Safety Instructions
Material/Parts
Silicone Adhesive (item 13 Appendix E)
WARNING
Voltages used can kill. Always disconnect power
cord to air conditioned before performing any
internal maintenance. Shutting unit off at its
control panel does not disconnect unit power.
a. Inspection.
(1) Check for loose or missing hardware and leads. Tighten and replace as needed,
(2) Check that terminals are not loose, broken or corroded.
(3) Check thermostat for evidence of overheating or other visible damage.
(4) Replace damaged or defective thermostat.
b. Test (Installed).
(1) Temperature test.
(a) Position thermostat in maximum cool position and apply heat (in excess of 80) to sensing bulb.
(b) Listen for clicking sound from thermostat control.
