Seen this message yet? It will pop up every few weeks not
knowing if you have or have not cleaned your filter.  You will
want to clean your filter every four weeks. It allows the
projector to breathe and will preserve your bulb longer.  Here
is a picture of where the two filters are located on your
Promethean projector. If you do not have a Promethean projector,
the filters may be in a different location. Here is what the two
filters look like.