I have the same Combo eel's. The Zigzag i bought him about a month ago and still shy when i hand fed him, he never ate so i gave up the the zigzag eel hand feeding. But getting him to eat is i turn off all the lights and feed him frozen blood worms and stick it in his pipe that he stays in then just leave. I come back like two minutes or so and its gone.
For the Peacock i bought about a week ago. He roams more around the tank than the ZZ eel does. The day after i got him i wanted to try and hand feed him and he did eat from my hand. How big is your tank and what do you feed him?