The other day I found where the previous owner did NOT clean the clean out holes behind the firebrick. I think I have removed 90 to 95% of that build up.

My flame became EXCELLENT but now I'm getting tons of ash on my firebrick after 12 hours of burning premium pellets!

Could this be because of another build up somewhere that I have not discovered? If so, could someone give me areas that I need to check out?

I'm thinking maybe I need to remove the exhaust fan housing to check from the backside of the fire box for build up?

Am I head in the right direction?

You'll get the ash build up, that's normal considering you are running a stirrer pot. That's one of the reasons to consider a clinker pot at some time.

Having found that much ash built up behind the firebrick area I would think it wouldn't hurt to check the blower motor cage. I took mine apart a couple of years ago and there was some build up but not much. But I clean my stove religiously weekly and a major cleaning in the spring.

Read in the sticky posted at the top of this forum for USSC and I believe there is information on removing the blower motor, there is a gasket that you have to be careful not to tear so that you can reinstall without buying a new one.

Another good thing to check is the roomfan blower, I had more crud built up in there than the exhaust blower. It will make the stove run a little quieter and move more air across the heat exchanger if the fins are cleaned. Some people even put a filter on them to stop dust and junk from getting on them.