With bright-colored dye and a fully equipped kit, you have everything you need to spot leaks in your HVAC system. These kits come with the correct amount of dye required for your system's size. Inject the dye into your system and scan it with the UV light—the dye is fluorescent, so it’s easy to spot most leaks right away. For small leaks, let the dye circulate for 24 hours and then inspect it again. Use the dye cleaner before you fix a leak. If the repair isn’t sufficient, you’ll be able to spot more dye.