I have a Trane Gas Furnace, model # TUE120A96OK3, that is 6 years old. I am having an issue with it where the burners will not stay lit. I check the red LED light diagnosis, and it says that it is having an "open high limit device" error. I thought that I could possibly reset or replace this to fix the problem, but I do not know where the Limit Switch is. Do you know if you can reset this switch to fix this problem or does it need to be replaced, or where it is located? Thanks for your help.