I was hoping to get some ideas on where this sound may be coming from. It is a “tapping” noise that seems to be coming from the inside of the firebox? It is very evident on low fan speed but is there on higher fan speeds. Almost like when different metals heat up they make noise but this is there at any temperature. It is intermittent and random in its tapping sounds. Air flow maybe? It is very annoying. Any ideas would greatly appreciated. Try this link for the sound clip (copy into your webrowser and it should open up in windows media player, I hope)…. http://dl.getdropbox.com/u/454647/HudsonRiver.wav Happy New Year.