When the weather began getting hotter recently, a customer called to say that his air conditioning wasn't working.  We sent out a technician, who discovered that there were no air filters in place and that the system had completely frozen up.  Air filters are necessary to filter out particles and keep the system from overheating.  While some premium filters can last up to three months, Sun Devil Plumbing & Rooter recommends changing your air filters once a month.  Try doing this chore on the same day you pay your bills every month for an easy way to remember.  It will save you money in the long run!