My nest is a couple years old and has been great until a couple days ago.
I went dark and has a flashing red light which I understand means it needs to charge so I let it charge but after twelve hours I began to suspect a bigger problem.
My installation lacks a c wire but that hasn't stopped it charging before. I measured the volts on the wires and they're all 27.2VAC to the red wire. I thought I'd try charging it via USB but it has become very hot and still complains that its battery is low.
I found a couple other posts like this but no answers. Just promises to pm for more info.
