My pilot light goes out after about 2 hours,I changed the TC but does the same thing.I have a nice blue flame when the pilot light is lit.What is my problem. HELP

Try to take pipe wrench and hammer the gas valve a little bit don't break it sometime you have restriction due to dirt in the line also make sure that the flame on th tc is big enough
Sometime
If you don't have it cover draft can extinguish the flame from the pilot
john