Just a quick question, I had to replace the vacuum hose to the pressure switch the other day(3 blink code, original hose, 9 year old furnace), swapped it out and furnace running like a champ again.
But while I was in there watching it before I closed up the cabinet to make sure all looked well I noticed that the flue collector box was pretty hot to the touch, but the furnace was working to get the upstairs back up to thermostat temp and to be honest I don't know if that is normal (kinda makes sense, heat is recirculating just behind it), I was going to grab the digital laser thermometer out of curiosity but my buddy had borrowed it, so no go that day. I also noticed a small crack towards one side of the collector box, but I've read online this is not unusual on Goodmans'...
Furnace ran fine, no limit switch going off, completed it's cycle, etc.etc.
Should the collector box be hot, and if so, how hot is normal??