After I changed the radiator to a koyo, I noticed my heater stopped working. I've rechecked all my work. Any idea where I can begin to debug the problem? I've already searched this problem with no avail.

 

same thing happened to me after my head gasket blew in my old car

 

You have air in your system. You need to bleed all the air out.

 

 

According to xvipers old thread, to bleed the air out, all you needed to do was run the car and allow the air bubbles to go into the reservoir. I've also tried running the car and jacking up the front to allow the air bubbles to rise to the fill port. Is there something else I am missing?

 

there are two bleeder valves that need to be cracked open as well to allow air to escape. not sure exactly where they are without looking for them but i think one is near the front corner of the Valve cover and one is on the back side of the engine.

 

I see the one near the back. I thought those were only used when letting fluid out. Thanks for the info.