A water inlet is an essential part of an RV’s plumbing system, allowing fresh water to enter from an external source. Whether you're hooked up to a campground's city water supply or filling your freshwater tank, a high-quality water inlet ensures a steady, clean, and leak-free water flow for drinking, cooking, and cleaning. Understanding how it works, maintaining it properly, and knowing when to replace it can save you from potential plumbing issues while on the road.