Just had my chimney cleaned for the year. I have a Jotul freestanding stove with a pipe that runs up through an old chimney. I've had the stove for about four years now and I have had the installers clean it every summer. The guys who cleaned it said that it was all ash in the pipe and it was really clean. I know I have heard recommendations that I have it cleaned every year and of course the recommend it. Once it gets cold I burn my stove every day for at least 1/2 of the day. Is it safe to have it cleaned every other year?