[kube-system]

You can always run a new one. I bought new wire at Home Depot, tied it to the old cable, and pulled it down to the basement.

[gww]

That only works if they didn't staple it to the wall or bury it in spray-foam insulation. I ended up having to run a new one but was lucky that the floor-board was under the garage. I ran a piece of cat5e as well in case there is ever an option to get a thermostat that can use it.

[IgorPartola]

I have yet to see the wires that aren’t staples to the inside of walls. If it’s an option, great but IME it’s rarely an option.

[kube-system]

High voltage wiring has to be secured, by code, but low voltage thermostat wires don’t, so it’s more likely that you can pull them.

[IgorPartola]

Ok but if the roughly 15 thermostats I have replaced in 8 buildings it has always been secured.