Posting this incase someone has the same issue. Bought a exp that had the heater core bypassed, was a Cali car so didn’t need heat there but now I’m stationed up in the cold and needed to fix it. Changed out the heater core, (pain in the a$$) but was still not getting any heat, I also flushed out the lines, took a few tries and was pretty nasty stuff coming out. Still no heat, and the lines weren’t getting hot like the radiator hoses. Well, decided to check the water pump…. Bingo, check the picture out. Heat pumping well now. So if your lines aren’t getting hot, check the water pump. By the way, it’s not suppose to be 2 parts like that lol!