I had my insert installed Monday, and I have only ran the stove on low and it works just fine. Last night I was home alone and I thought I would burn the stove on high and get that new paint smell burnt off. At about 15 minutes while on high the led comes on it says the flue has reached high temp. and it turns the stove down not completely off, but until the fire is almost out then it will fire back up and run about 8 more minutes and do the same thing. If I turn it back to medium it will burn about 15 minutes the led will come back on, same thing happen the fire goes almost all the way out, then it will start back up burn about 15 minutes and I get the same results. Now it I turn it down on low, even after the Flue temp. LED comes on while in the high mode or medium setting it stove just contiues to burn without a problem. But if I select high or medium both setting do the same thing. The book says clean the stove and heat exchaner and so on which I have done. I did not clean the pipe because the pipe was just put in when they unstalled the insert. I really doubt if this normaml, would like to hear some suggestions, for should I just call the dealer and see what he says.