I only ran the heat on my double boiler until the temp of my honey reached 125 degrees, then cut the heat. It seemed to take about 30 minutes at that temp to return to liquid honey. The end product is the clearest, most perfect looking honey that I have ever had.
You don't really want to get honey above that temperature. Doing so will start a Pastaurizing process that kills all the real benifits of raw honey: antiseptic, would healing, hayfever, etc.