The red box is where the leak appears to be (under the igniter), and the arrows is where the air is coming out. I assume there was a gasket between the igniter and housing assembly, but I'm not sure. The burner still apparently runs OK, and I don't smell any funny smells. However, I would also assume the air-to-fuel mixture isn't correct anymore... any suggestions? Getting a technician to come out is so expensive, especially when the burner still seems to work!