Apr 23, 2021 - 04:18 AM
The “DF” means the system is in “Defrost Mode”.
There are several things to check to help prevent this from happening: The unit could be working too hard to cool beyond the 18° – 22° drop.
Remove the ceiling assembly and check that everything is taped off properly.
Remove the shroud and check the coils for the buildup of debris, as this can cause overheating and low circulation.
Ensure all ceiling returns have the same airflow and temperature output. Lack of flow or warmer air in one return could indicate an issue with the ductwork.