Pea Coal Burning in Hopper

I use a surdiac hopper feed coal.just filled hopper and noticed small bits of pea glowing near the top of hopper.does this mean I have a gasket that has to be replaced.gasket is around
loading door above hopper?orginal gasket.stove about 15 years old.
edd

I am nowhere near an expert am learning myself but was talking to one about my stove which has a similar style hopper and he explained to me to keep that top hopper loading gasket like new or you will introduce air into the top instead of the bottom and will have problems which you are experiencing and thought I would pass on