I wrote about this before. My 2006 Accentra is reading room temperature "funny" on room temp. mode. It seems about 10 degrees off. I mean I have to set it over 80 degrees to get the room to 72. It never used to do this. Have run about 15 tons of pellets probably since I owned the stove. (I do clean the vent pipe and stove insides, too) Well, I finally took the esp probe out of the ehaust and cleaned it with a green scrubbie pad. It only had a very very thin layer of carbon on it and some ash. Well the stove still seems to do the same thing. If there is any improvement, maybe its too slight too notice. Is this probe getting old and time to replace? Also, this probe has the black wires. What the hell is the difference (other than the inside resistance , maybe? or length?) between red and black wire probes? How silly to have 2 probes that I swear look totally alike only that they have different colored wires. Also, if I buy a new probe, I should only buy a Harman part right? I see a lot of aftermarket parts now. I have no clue if these aftermarkets are just as good as Harman parts or if an aftermarket ESP probe even exists.