dirty air conditioning filter A dirty air filter can be to blame if your central air conditioning unit hasn’t been working the way it should lately. A host of problems can occur with this filth and, in the most extreme case, the complete breakdown of your AC. If your AC is still working, licensed technicians can take a look at your air filter and clean or replace it if necessary. If it’s too late, and your air conditioning unit has already suffered a breakdown, you can get help for that too. Worst-case scenario, you may need a new AC unit.