So I'm on my 2nd one of these heaters. Heating wise, they work great, but both have had the thermostats fail and the built in shut off failed as well. The first time this happened the temperature in my garage reached 127 degrees. The second time, this morning, the temperature reached 111 degrees. The 2nd unit was a replacement and I assumed the first issue was a fluke and I was lucky that my garage was still standing. There is nothing like walking into a room that is 127 degrees. The company doesn't seem to be overly concerned, but this should concern anyone that doesn't want a fire to occur. The first unit was inside of 2 years old and the the 2nd just inside of 4 years. The end result is that products can wear out, but the safety features should not fail as these have. Notice the high temp on the attached photo.