When they first appeared, they carried a lifetime warranty. A few years ago they changed it to three years. Check with Testors, since yours had been replaced three years ago.
I used to be a proponent of the Aztek, but their quality slipped--badly--a few years after they made their debut. The tips go erratic, the bodies leak, and then they changed the warranty. I switched back to my Badger 150 and 200 and haven't had near the same amount of problems that I had with the Azteks as they got older.
Ralph