COStar 24VC-e Main Board and Sensor Replacement kit for COStar 24VC made by Quantum Group. The life of Quantum COStar 24VC-e main board is 12 years. It will beep 60 days before the end of its life so that you have time to purchase this board and sensor replacement kit. Also this replacement kit is perfect for customers who own COSTARŽ 24VC carbon monoxide ventilation control to retrofit. Since the first generation is obsolete we cannot offer a replacement sensor for these old 24VC, therefore we have developed a board and sensor replacement kit. It is much easier and more cost effective to replace a board and sensor than to replace the whole installation.