Having issues with getting the heat to work again on my suburban. Replaced the radiator and after that the heat ceased to work. I burped the system and it didnt change anything. Looking for help with this issue.

 

Are both hoses hot?the ones to and from heater core

 

When running it seems there is no coolant in the lines coming from the intake on the back side. I tried to find the factory heater bypass, but it shows 2. One for if there is now rear climate control which is a standard 2 in 2 out valve. The second is a small what looks to be a switch with what looks like to ports for vacuum hoses and a 2 prong connecter. Ive already flushed the system 6monthes prior to the radiator blowing up and had perfect heat. Now there is nothing and just blows cold with a slight twinge of heat. That of which I'm assuming is just heat coming from the motor.

 

I don't know how long you have been trying but it took me forever. Park on a steep hill and let it run or use ramps and make sure there are no leaks at all.