I have a bradford white defender water heater. The pilot goes out intermittantly. The thermocouple has been replaced, the screen has been cleaned and everything was adjusted, yet it still keeps going out, sometimes it will stay lit for a day or two but most times it goes out within a half hour or so. I thought the thermal reset switch was to blame seeing how it is always popped out, but after removing it and very crudely testing on the stove it seems to be good ( it is supposed to shut off at 270 degrees and it went to 250 and beyond before popping out so I assuming its good). What could be causing it to get so hot, or is something else I am missing here. I all can think of is improper venting of the exhaust causing the hot gases to build up and to make it get too hot. Any help would be greatly appreciated. Thanks you in advance.