KitchenAid KBFA20ER Technical Education page 60

Symptom
Frost or ice on evaporator
Unit starts and stops frequently
(cycles on and off)
Possible Causes
Defrost thermostat faulty
Evaporator fan faulty
Defrost heater remains open
Defrost control faulty
Open wire or connector
Refrigerant shortage or restriction
Loose wire or thermostat
connections
Supply voltage out of specification
Overload protector open
Faulty compressor motor capacitor
(some compressors do not require
motor capacitor)
Faulty fan motor
Restricted air flow
Refrigerant shortage or restriction
6-8
Corrective Action
Check defrost thermostat. Replace if
failed.
Check fan motor. Replace if failed.
Check defrost heater continuity.
Replace if failed.
Check control and replace if failed.
Check wiring and connections.
Repair as necessary.
Check for leak or restriction. Repair,
evacuate and recharge system.
Check wiring and connections.
Repair as necessary.
Check input voltage. Correct any
supply problems.
Check overload protector for
continuity. If open, replace overload.
NOTE: Ensure
overload/compressor are below
trip temperature before testing.
Check capacitor for open/short.
Replace if necessary.
NOTE: Discharge capacitor
before testing.
Check fan motor. Replace if failed.
Check condenser and grille for dirt.
Clean.
Check for leak or restriction. Repair,
evacuate and recharge system.