WeÂve recently purchased a Bis Nova Fireplace and were told that you cannot use anything but their certified chimney system. Their system is extremely expensive. We found virtually the same chimney system (SuperVent) at Home Depot for a fraction of the cost. A Bis Nova dealer then said if we install anything but their chimney product we would not be able to have the fireplace WETT certified and the insurance company would have us ripe out the supervent chimney from Home Depot. This seems like a huge money grab for Bi Nova. Has anyone come across this issue before?