gas logs not staying lit
I am having a problem with my gas fireplace. It is a vented system. i filled the tank and lit the pilot and used it for about a week. When it gets cold,mid 20's or lower, the fireplace goes out. It will not start up and the pilot will go out. I had this problem towards the end of winter last year. a service tech adjusted the vent opening. It seems as if the gas line is freezing. Is that possible? Please help with any suggestions.