Something does not seem right. You should not be going through thermostats like this. The only way to fry a thermostat when installing it is to reverse the power and ground connections. I can't believe the HVAC company told you this has happened to several people.

Did the tech measure the voltage going to the thermostat? Is the ground connection continuous back to the control board?

Is the house dry and do you have a lot of static electricity? Thermostats have electronic components which can be damaged by an electrostatic discharge.

I think the problem is the installation. I would not trust the outfit you hired.

Have to agree with Mike...

Pls I will add I am not a fan of these lifestyle thermostats.

Who installed the Ecobees?

This is a furnace? I do not even see a Gold XV model listed.

IMO

I'm a huge fan of my Nest thermostats, though I've heard people have had problems with some strange wiring situations. Mine have been running flawlessly (both in our old condo, and our new house) for almost 3 years.

If you're having wiring problems, the installer should have installed an isolation relay and a separate 24V power supply for your thermostat. That's really basic HVAC wiring. If he didn't start there, I wouldn't let him back in my house.

The issue was corrected the next day. The tech they sent out is not good at the new technology with thermostats. Yes, he literally fried the new one. The guys who came to replace the replacement They dropped a new electric line from the air handler to the thermostat. The install of the new thermostat went without a glitch. This is on a variable speed air handler.

Thus far I'm liking the new thermostat, and no that installer won't be stepping on my property again. Before you ask - the company picked up all of the charges, etc.