I have no clue why people like their thermostats to the degree that they do.. I am both an A/c professional and an Engineer. They use what is called an SCR or silicon controlled rectifier for their switching instead of a tiny relay. An SCR is very sensitive to a spark or voltage spike. Yes the thermostat is pretty cool and has some nice features. It is advanced electronics but using SMC's or Surface Mounted Components?? . Maybe that would work well in a shielded component. But NOT in something that is connected to long external wires. The consumer bought warranty is only one year. I have seen too many issues in the field with their overpriced toys. Not having parts for this Chinese made thermostat? Priceless.