I finished hanging my two Delta air cleaners and they work great except I can't get either one to work with the remote control. I tried all the usual tests; fresh batteries, testing each control on each machine but nothing works. I can hit the buttons on the units and that is the only thing that will start them. These are two new units and the only thing that is suspecious about the whole thing is the photo illustration in the manual. It points to a bolt head indicated by "E" and calls it the power light. Any ideas?