At the time I had my kitchen and hallway tile put in I mentioned in floor heat to the contractor and he looked at me like I was wierd. That was in 1990. I was wondering if there is a way I could remove the grout around the tiles and put in copper wired electric in floor heat?

I've never seen it done before, best to talk to the grout manufacturer and tilewarmer manufacturer to see what they think. My first thought would be that the grout would crumple in no time at all with much direct heat on it.

If you use electric mats, you can install heat in the floor, and install tile directly over the mats, using adhesive methods. If you have access to the area below the floor, you can also install hot water piping and appropriate insulation below your floor.