FS80...runs like a champ, fires right up when cold. After using, good and hot, shut it off, you can refire immediately. If you wait 10 minutes, 20 minutes, it wont' fire for anything. At that point you have to wait a hour or so for it to cool completely, then it refires as it should. Any ideas?? This unit is bout 5 years old but in very good condition, (cept as noted above). Thanks for the input.