F21 -01 — Evaporator temperature sensor is shorted, broken, or freezing

What does F21 -01 mean?

This error indicates a problem with the sensor measuring the evaporator temperature. It could be shorted, broken, or the unit may be freezing due to a freon leak.

• The evaporator temperature sensor is faulty.
• There is a freon leak in the system.
• The unit is experiencing freezing conditions.

Click steps to track your progress.

1. 1

   Check the evaporator temperature sensor for damage.

2. 2

   Verify that the unit is not freezing up.

3. 3

   Ensure proper freon levels if possible (professional check recommended).

4. 4

   Turn off the unit, unplug it, wait 30 seconds, and plug it back in to reset.