I just shop-vacced the inside of my stove before lighting a fire and saw these cracks at the bottom of the combustion chamber on my Harman TL 300. The last fire of last winter the gaskets that hold the combustion package in place fell out, but apparently according to my dealer its no big deal. Now I see these cracks. Is this something I need to be concerned about? The harman logo brick is missing in front because it kept cracking and at $40 a piece my dealer told me to quit buying them.