I picked up a pipe thermometer at my local hardware store and when I read the packed it said for single walled pipe only and of course I have double. Me being inpatient and dumb I read it after I brought it home, it was relatively inexpensive so I threw it on the pipe just so I could get some kind of reading. My question is since my pipe is double walled what is over heating for it. When the stove is going the temp gets up to about 250 F. at the hottest but the stove is kicking off plenty of heat.