Product review (5 stars): Give it a try before calling a professional.
My old gas stove was not getting very hot and was taking a long time not to get hot.  A Google search provided the diagnosis of a bad igniter.  After watching a YouTube video on how to replace one, I took on the project myself.  No problem.  $25 repair gave me back a stove that heats properly and rapidly.  I am slightly handy, but by no means an expert DIY-er.  Give it a try-- at worst, you would still have to call a repair person or replace the stove (which wasn't heating anyway).