Coolant Frozen

[JET]

If it is frozen solid enough you won't be flowing any water to the temp sensor. Essentially you are overheating your car, but you wouldn't be able to tell.

[Tsi]

Well I did what u said Jet, and finally it went back to normal temps and the radiator finally feels hot, I kept checking the radiator while running and it was cold as ice...now its hot and car isn't overheating or anything, but the heat still doesn't work. I just got back from the coldest drive ever...no heat and -20 outside, great stuff. Car runs fine and everything, its just that there is no heat anymore