What FD Lo / FD Hi / rD Lo / rD Hi (111-prefix) Means
FD and rD codes on 111-prefix Kenmore bottom-freezer refrigerators report the defrost sensors — FD for the freezer side, rD for the fresh-food side. These sensors tell the control when a defrost cycle has done its job, so a failure here shows up as frost building where it should not.
Common Causes of FD Lo / FD Hi / rD Lo / rD Hi (111-prefix)
- A defrost sensor out of its resistance range
- Damaged wiring between the sensor and the control board
- A control board misreading an otherwise sound sensor circuit
🔧 One Safe Check You Can Try
Look at the back wall inside the freezer for a sheet of frost growing over the vents; that is the visible symptom, and noting it helps before anyone opens a panel.
⚠ Why You Shouldn't Go Further Than That
- Unplug the refrigerator before the evaporator cover comes off; the defrost heater behind it runs at line voltage.
- Evaporator coil fins damage easily during access, and a pierced coil turns a sensor job into a sealed-system job.
- Clearing the frost by hand relieves the symptom for a week without touching the sensor that caused it.
Opening a panel to inspect or repair something yourself doesn't automatically cancel your manufacturer's warranty — but it can risk accidental damage, and some manufacturers do have specific service conditions. Check your product's warranty terms, or ask us, before deciding.