I don't have an HD Homerun, or any kind of PVR so I can't test this but it does sound like an issue with either Kodi or the HD.

I suggest you post your question on a Kodi forum.

The one obvious thing to try is to stop playback first before changing channels.

In the future, please post logs or XML or in a code box, not as a quote.

QuoteHi -- finally figured out how to get Live TV on Kodi with the HD Homerun Prime.  Trying out some of these Live TV commands -- from Kodi homescreen, I am able to say "Switch/play to channel [two]" and it will pull up the correct channel.  However, while channel two is playing and I try to change the channel "Switch to channel [four]", I get an error in Kodi, where it says "NextPVR: Tuner not available".  So, really can only use the switch command once.  I know the tuner is working, because even though I can't voice command anymore, if I go into the Live TV view, and just select channel four, it switches over.

Hi Hiryu,
I'm using these same commands in kodi 14.1, all work perfectly for me.
Updated a couple commands on my original post, to better suit the new Kodi api, but this particular command i haven't chanced.
I use tvheadend not Homerun, about the only difference.
Could try adding in a 'Stop' command at the start so it will stop the current channel before changing over.