Took some time today and did a good mid-season cleaning. Having two boys headed back to college this week, I was about to lose my muscle. Removed the insert from the fireplace, cleaned the pipe and the chimney, disassembled and cleaned both blowers and replaced the gaskets. I have had a minor vibration for a few weeks and found the bolts on the combustion blower loose. Pulled both baffle plates, vaccumed everything and wire brushed down the burn pot. Oiled the convection blower, cleaned the glass and fired her back up. It is amazing how dirty these things get in places that you can't see after just two tons. Well worth the few hours of time. No more vibration!