A thermocouple replacement is a simple job for a qualified gas fitter such as a plumber. Alternately, you can try to clean the thermocouple and see if that fixes the issue. Your thermocouple is likely not recognizing the pilot flame which is causing it to go out. You will want to clean the thermocouple with a piece of emery cloth or high grit (1000) sandpaper. This may resolve the issue.
Tyler M. - NFI Master Hearth Professional
on October 30, 2019