Rinnai’s outdoor tankless water heaters are known for reliable, on-demand hot water. The REP199eN model stands out because it learns your routine. Its Smart-Circ technology memorizes your household’s hot water patterns and activates its built-in recirculation pump only when you typically need it. This means hot water arrives faster at the faucet, but the system doesn’t waste energy circulating water all day.

With a maximum flow rate of 7.9 gallons per minute, this 199,000 BTU unit can handle simultaneous demands in a large home. Think of running a shower while the dishwasher starts a cycle. The hot water keeps coming. Because it’s an outdoor model, you save valuable interior space and don’t need complex venting. Installation is simpler, and the 120-volt power requirement is standard.

The system’s intelligence is its main advantage, but it requires an existing recirculation line or a crossover valve under your most distant sink. That’s a key installation detail. For homes sized appropriately for its output, it delivers consistent performance and tangible energy savings by working on your schedule, not a timer.