A non-condensing RV tankless water heater utilizes a specialized heat exchanger to heat water on demand. This has the advantage of being very dependable as well as long-lasting. The disadvantage is that heavy-duty stainless steel venting is often required to discharge the hot exhaust gases. As a result, the final cost rises. When using a condensing tankless water heater in an RV, heat is obtained by reusing exhaust system heat. They are less energy efficient when used in short bursts like hand washing or rapidly rinsing soiled dishes one by one. However, since they utilize PVC venting, they are less expensive.