I am burning in my Englander NC30 for the first year and have noticed that whenever we get a fire blazing (just before the secondaries kick in) the stove has a tendency to "talk." The stove will begin to make creaking and groaning noises (I am sure it is from rapid metal expansion/contraction). I figured after a few weeks the noise would go away, but here we are several months into the burn season and so far it makes noise every time we hit that threshold. Is this anything to be concerned about?