Heating GENTLY (mind that word 'GENTLY') works fine, and is the only
method we used for years. We set the entire kettle into the OVEN (better
than a burner for uniform heating)  for 24 hrs at about 120-130F.  IF you
think separation is complete, let it cool for a day. You get one big cake of
wax on the top, and honey is not damaged. The pan/kettle is so screwed up
with wax that you will never be able to use it for anything else. After
about 15 years of doing this, I finally bought an extractor last year,
figuring I might as well go modern at last.
 
        HBCanon
        Geneva, FL