How do I change Wi-Fi channel on Apple TV?

I have two (2) Apple TV's in my house. One of them keeps disappearing from the Airplay icon on my iPhone, iPad and iTunes on my Dell laptop. This Apple TV does everything else that it should do, plays iTunes Radio, movie trailers play fine, podcasts, it just can not be seen by my devices. It occasionally does show up but disappears very soon after. My other Apple TV works fine, does all it should and is always seen by my devices.

The one thing I have found is the good ATV is showing its on Wi-Fi channel 11. The problematic ATV is showing channel 36. After trying everything under the sun I am hoping this is the problem. BUT how do I change that channel from 36 to 11?

I just returned home from an Apple store and no one there had a clue so I'm asking here.

Thanks in advance for any help. And out of curiosity, why would this one unit be at channel 36???