Answer: For homeowners seeking high-efficiency propane tankless hot water with compact form factors, these five models deliver reliable on-demand heat, space flexibility, and smart controls. Best for: multi‑bath homes, outdoor installations, and spaces that require energy‑savvy performance. The following selections prioritize propane compatibility, compact design, and clear efficiency advantages to help you pick the right unit without overpaying for features you won’t use.
Summary of top picks
| Product | Best For | Key Benefit | Notes |
|---|---|---|---|
| NEW Rinnai RX199iN | Homes needing high flow | Up to 11.1 GPM, versatile indoor/outdoor install | Smart Sense with Versa Vent; WiFi control module available |
| Rinnai RE199iP Non-Condensing | Mid‑to‑large homes | Up to 9.8 GPM, compact footprint | Indoor installation; standard 15/5/1‑year guarantees |
| APUS 190,000 BTU Outdoor | Outdoor setups, strong demand | 8.1 GPM; remote control via Tuya app | Outdoor‑friendly; 0.79 GPM min flow for pressure variants |
| Rheem LPG Condensing 8.4 GPM | Budget‑conscious, outdoor needs | High efficiency; 180,000 BTU capacity | Outdoor installation; durable cabinet |
| Rinnai RX160iN | Versatile, mid‑range flow | Up to 9 GPM; compact for indoor/outdoor | Condensing design; control options via Controlr |
NEW Rinnai RX199iN Condensing Tankless Water Heater
- Best for high-demand homes: up to 11.1 GPM, suitable for multiple fixtures simultaneously.
- Install flexibility: indoor or outdoor with Versa Vent; supports propane or natural gas via Smart Sense.
- Smart features: easy interface, Quick Flush, and a high energy efficiency (UEF .98); Controlr module for WiFi control (not included).
Best for buyers who want the maximum hot water flow from a compact unit and value flexible installation options. Caution: outdoor use requires the RX-OVC vent cap.
Rinnai RE199iP Non-Condensing Propane Tankless
- Smart design: heats only as needed to save energy; compact suitcase-sized footprint.
- Up to 9.8 GPM; indoor installation suitable for many homes.
- Guarantees: 15‑, 5‑, and 1‑year residential coverage for key components; optional Controlr module for WiFi (not included).
Best for mid‑to‑large homes that want strong hot water performance without condensing efficiency requirements. Limitation: non‑condensing design may be less energy efficient than condensing models in long‑term usage.
APUS 190,000 BTU Outdoor Tankless Water Heater
- Best for outdoor setups: 8.1 GPM with reliable performance even under lower water pressures (0.79 GPM min flow).
- Smart control: app control via Tuya app and wired controller (temperature range 95°F–149°F).
- Compact outdoor unit with standard 3/4″ connections; straightforward outdoor installation.
Choose this if you need a dedicated outdoor solution with remote temperature control. Caution: outdoor exposure requires weather-rated enclosure and proper clearances.
Rheem LPG Condensing Outdoor Tankless 8.4 GPM
- Best for outdoor spaces that demand steady hot water: 8.4 GPM at 180,000 BTU.
- High efficiency design offers strong performance in cooler weather.
- Outdoor installation with a durable metal cabinet and wall‑mount capability.
Best for budget‑minded buyers needing outdoor capacity with reliable performance. Limitation: non‑condensing design may be less efficient long‑term compared to condensing units.
Rinnai RX160iN Condensing Tankless
- Versatile: up to 9 GPM; indoor or outdoor with Versa Vent and Smart Sense control.
- Condensing efficiency: high efficiency with Quick Flush and WiFi control options (Controlr, not included).
- Compact footprint suitable for tight spaces and various installation layouts.
Best for households needing dependable mid‑high flow with efficient condensing design. Caution: ensure outdoor venting requirements are met for outdoor use.
Rinnai RE180iP Non-Condensing Propane Tankless
- Indoor non-condensing option with up to 8.5 GPM.
- Smart design emphasizes energy conservation and serviceability.
- Includes 15/5/1 year residential guarantees; WiFi control via Controlr module (not included).
Best for buyers prioritizing straightforward indoor installation and predictable hot water with solid efficiency. Limitation: non-condensing units may have higher operating costs compared to condensing models over time.
Buying Guide: Key Considerations For Propane Tankless Heaters
What size GPM do you need? Consider peak demand: number of showers and fixtures used simultaneously. For larger homes, units approaching 9–11 GPM handle multiple points of use; smaller homes can manage with 5–8 GPM models.
Indoor vs outdoor installation: Condensing models are typically better for indoor use due to higher efficiency and venting flexibility; outdoor models require weather‑rated housings and proper venting.
Condensing vs non-condensing: Condensing units reclaim waste heat for higher efficiency (UEF often near .97–.98). Non-condensing units are often less expensive upfront but may cost more to operate over time and vent differently.
Venting and controls: Versa Vent options and WiFi control can simplify installation and future upgrades. Ensure you have the compatible vent caps and control modules, or plan for replacements.
Warranty and serviceability: Look for residential guarantees on heat exchangers, labor, and parts. Service access and ease of replacement can save time and money during maintenance.
Installation considerations: Confirm gas supply capacity, space constraints, and local code requirements. Some units require professional installation and venting compliance.
Frequently Asked Questions
- What is the benefit of a condensing propane tankless heater?
Condensing units reuse exhaust heat to improve efficiency and reduce energy use, which can lower operating costs over time.
- Do I need an outdoor vent or can I vent indoors?
Indoor venting is common for many models, but outdoor installations require weather‑rated venting and sometimes different caps or housings.
- How many fixtures can a typical 8–9 GPM unit serve?
Typically 5–7 fixtures, depending on faucet and shower usage; high-demand homes benefit from higher GPM units.
- Is non-condensing always cheaper than condensing?
Yes, upfront non-condensing units are often cheaper, but long‑term energy use and maintenance may be higher.
- Can these heaters provide hot water for a whole house?
Yes, most models listed are designed for whole‑home use with multiple fixtures operating simultaneously.