When you choose a NuFlow-certified contractor, you're choosing to work with a professional who has been trained and certified. All NuFlow Certified Contractors are required to complete a rigorous, hands-on training program before they can become certified. They also must pass an exam that tests their knowledge of NuFlow products, installation techniques, and safety guidelines. Choosing a NuFlow-certified contractor ensures your system will perform at its peak level for years to come.