C.C.
We have had this exact issue with our oldest daughter (who is now 5.5). We went the route of the pediatrician picking out the wax, and one time they flushed her ears with warm water and it made her ears bleed (she was screaming, it was awful, and that was the last time we visited that pediatrician).
We found a more old-school pediatrician after that who gave us some great advice. Simply put mineral oil in your child's ears for a minute or two, maybe every other week (or as often as you need to). This will soften up the wax and it will flow right out. No pain, no expensive drops that don't work, no trips to the doctor. It has worked really well for us so far. I hope it works for you too!