I must be lucky! I got ten years out of my first Wagner and would have gotten many more years if I hadn't dropped it one too many times and broken the ceramic in the heating element.
Wagner #2 has been running trouble free for at least the last 5 years. As you all know, I do a lot of heat correcting, hundreds of bows and billets, so my heat gun doesn't sit idle for long. I can't understand why all of your heat guns give up the ghost so quickly.
To keep from burning myself on a heat gun laying on my bench( done way too many times), I made a holster from aluminum to drop my gun in between heating sessions. I haven't knocked my gun off of my workbench onto the floor since I made the holster, something I used to do on a regular basis.