Time running before defrost may be too long, a sign the timer is going, maybe. Most aren't too expensive. I would still make sure whatever it uses to evaporate condensate water is working. Usually a type of heater or even a HotGas line in the pan.
With the people left unguided, For so many troubled years
In a cloud of doubts and fears, Their world was torn asunder into hollow Hemispheres......Neal Peart