Rick Blaine wrote:
Tony Hwang wrote:

If it is mil-spec'd one, then that is again different category.

And if you think Honeywell or any other stat manufacturer is buying mil-spec or
even industrial spec components for their stats, you would be very wrong... Even
if they were (they aren't), those specs mostly relate to harsh environment
(vibration, temperature, salt fog atmosphere, etc.). None of those apply to the
typical household environment and none will extend the life of a component.

Furthermore, no manufacturer would buy "seconds" or QA fail components to
populate production devices. They'd fail product QA or the retailer/distributor
returns would quickly put the company out of business.

It is quite common to use "seconds" in manufacturing. Where this is most
common is in electronic component manufacturing. There will always be a
range of quality in any production run. Stuff that doesn't meet the
first quality spec is labeled as some other quality and sold off or
used to make a cheaper version of a product (often the big box version).