I have an Aloha Breeze heating unit Model #02044. It stays on for 2-3 minutes and then turns off. It will not stay on when the switch is turned to "on" position.

Ya see, what you need to do is take it apart and clean it
thoroughly. Clean the filter and the heating element. Insure proper air flow.

I followed the advice above by cleaning the back filter with a damn paper towel the issue was fixed! Thank you very much as I was having such a hard time finding one to replace it :-). Now I don't have to and it works perfectly fine.