Rinnai R94LSi Indoor Tankless Water Heater (Discontinued)

The Rinnai R94LSi is a 199,000 BTU indoor non-condensing tankless water heater, now discontinued in favor of the current RL199iN Sensei platform. It remains in service in many residences installed 2012 through approximately 2020 and is encountered primarily in two scenarios: existing-unit replacement and parts service for in-service units.

Specs: 199,000 BTU natural gas input (R94LSiP is the LP variant), UEF 0.82 (non-condensing), 9.4 GPM at a 35°F rise, copper heat exchanger, 4" Category III stainless steel B-vent venting. The 9.4 GPM peak is meaningful for whole-house residential demand — capable of two showers plus a kitchen tap simultaneously in southern climates.

The non-condensing design was historically chosen for retrofits where existing chimney access made B-vent venting cheaper than the PVC venting that condensing units require. Today, the cost advantage has narrowed and most new installs go condensing. For homeowners with an existing R94LSi nearing end-of-life, the current RL199iN (non-condensing, same install footprint) is the direct replacement option, while the RU199iN condensing requires new PVC venting.

Service: Rinnai's dealer network supports the R94LSi for parts through 2030. Common service items match other Rinnai tankless: flow sensor, igniter assembly, flame rod cleaning (not replacement), inlet water filter. For units throwing fault codes consistently in year 10+, repair-vs-replace decisions usually favor replacement with the current platform.

Used R94LSi units appear in marketplaces at $400–$700 — substantially below the new RL199iN price ($1,400) but without warranty transfer and with unknown service history. For a primary residence install, used purchase is high-risk; for a vacation home with light use, used can be acceptable.