Just started using my xxv this week and have noticed that it seems like it's stuck in one heat setting, like #3 based on the amount of pellets in pot. this happened a few years ago and a tech came out and a vacuum hose somewhere near the fines pot had come off and this was causing the issue. Appears to be doing same thing now and I think I vacuumed out fines box in spring and perhaps knocked this vacuum hose loose again. Acting same exact way. Can somebody tell me where I look for this? I peeked my head around near fines box and can't see a vacuum hose.. Thanks