So like I said- builder grade. If you had a company come in to install a system, you can pick from many options and features, like multi stage pumps, variable speed fans, etc. the base models from these companies are “builder grade” because it’s basically the cheapest model they can install in 100 houses they’re building. You can look up your system specs online and also see what other similar models are in the product line. You dont need the most expensive system to have good cold weather performance, but you may not get it on the cheapest model.
I never knew about the limitation but the hvac guy was right. Once it went over 0. The heat kicked back on. We rarely get below zero here and that’s why they don’t installed the secondary heat source.
If it's that specific that it happens at an exact temperature, it sounds like an intentional "fuck you" switch on that model disabling it and not an actual physical limitation.
We have a very mild climate historically. The last few years the summer have been really hot but the winters aren’t to bad.
They don’t plow or salt the roads in the winter. When it snows and ices, the town just shuts down. It’s really weird to me having lived elsewhere.