When selecting a liquid propane tankless water heater, Americans often look for reliable flow, strong BTU ratings, and compact installation options suitable for indoor or outdoor spaces. This guide reviews top-rated LPG tankless models that deliver on-demand hot water, energy efficiency, and ease of use. Each product section highlights key features, performance, and installation considerations to help you choose the best fit for a mid-sized home or multi-occupant household.
Product Comparison Snapshot
| Product | Brand | Flow (GPM) | BTU | Install |
|---|---|---|---|---|
| RTG-70DVLP-3 | Rheem | 7.0 | 160,000 | Indoor |
| MIZUDO Tankless | MIZUDO | 5.1 | 120,000 | Indoor/Outdoor |
| RTGH95DVLP3701178 | Rheem | 9.5 | 199,900 | Indoor |
| Rinnai RX199iN | Rinnai | Up to 11.1 | 199,000 | Indoor/Outdoor |
| RTG-84DVLP-3 | Rheem | 8.4 | 180,000 | Indoor |
Rheem RTG-70DVLP-3 High Efficiency Tankless Water Heater
This non-condensing indoor unit delivers up to 7.0 GPM, making it suitable for homes with 2–3 bathrooms and multiple hot water needs such as showers and laundry. Powered by 160,000 BTUs of liquid propane, it provides fast, reliable hot water even during peak demand. Its compact metal cabinet is designed for indoor installation with wall mounting by a qualified installer. The model targets steady performance in moderate climates and smaller households seeking immediate hot water without a storage tank.
MIZUDO Tankless Water Heater Propane
Designed for flexible indoor or outdoor installation, the Mizudo heater supports conversion with accessory kits to adapt to space and climate. It features WiFi and app control for remote management, temperature adjustments, energy monitoring, and maintenance alerts. Advanced temp control modulates gas and water flow to sustain stable output, even when multiple fixtures run simultaneously. The unit aims to keep water temperature within a narrow margin, enhancing comfort for households with varied hot water demands.
Rheem RTGH95DVLP3701178 9.5 GPM Indoor Tankless Water Heater
Rheem’s RTGH series offers a high flow rate with up to 9.5 GPM and nearly 200,000 BTUs. This indoor unit supports higher simultaneous hot water uses, such as multiple baths or showers, and includes electric ignition for automatic lighting. With a broad operating range and robust construction, it’s positioned for larger homes or households with demanding hot water needs, delivering quick hot water with consistent temperature control.
NEW Rinnai RX199iN Condensing Smart Tankless Water Heater
The RX199iN is a versatile condensing unit that can operate on propane or natural gas, install indoors or outdoors with Versa Vent, and deliver up to 11.1 GPM. Its compact footprint makes it suitable for tight spaces, while the Smart Sense control system optimizes efficiency. Features like a Quick Flush option and a high energy factor (UEF) contribute to water heating efficiency. A control module supports WiFi integration, though some features may require additional components.
Rheem RTG-84DVLP-3 High Efficiency Tankless Water Heater
This 8.4 GPM LPG model pairs strong flow with 180,000 BTUs for reliable hot water across 2–3 bathrooms. Its indoor design features a durable cabinet and simple wall-mounting, making it a practical upgrade for homes needing more hot water without a storage tank. The unit is built to perform during peak demand, balancing efficiency with effective heat delivery for busy households.
Buying Guide: Key Purchase Considerations
- Flow rate vs. simultaneous demand: Determine your household’s hot water needs by listing fixtures used at once (showers, sinks, laundry). For busy homes, target models in the 9–11 GPM range to prevent temperature fluctuations during multiple uses.
- BTU and gas input: Higher BTU values generally support greater flow and faster recovery. Match BTU to your propane supply, space, and venting capabilities. Non-condensing units are typically simpler but may vent more heat loss; condensing units are more efficient but can require more complex venting.
- Indoor vs. outdoor installation: Indoor units require venting and compatible clearances; outdoor units must withstand weather and may need weatherproofing and frost protection. Consider climate and available installation space when choosing the location.
- Condensing vs. non-condensing: Condensing models (higher efficiency) recover more heat from exhaust gases but often cost more upfront and may need more sophisticated venting components. Non-condensing units are common and straightforward but may lose more heat in exhaust.
- Ventilation and venting options: Confirm compatibility with existing venting systems or required vent kits. Some models use direct venting suitable for tight spaces, while others need dedicated venting routes.
- Smart features and control: WiFi/app connectivity can simplify temperature management, monitoring, and maintenance alerts. Ensure compatibility with your smart home setup if desired.
- Installation requirements: Tankless water heaters require professional installation for gas connections, venting, gas line sizing, and electrical wiring (for ignition and controls). Verify local codes and warranty conditions.
- Maintenance needs: Periodic flushing and descaling may be necessary, especially in areas with hard water. Look for units with easy access panels and service-friendly design.
- Reliability and warranty: Check manufacturer support, parts availability, and the warranty length. A well-supported model reduces downtime and service costs over time.
- Space and noise considerations: Indoor units should have adequate clearance and vibration dampening. Check the unit’s dimensions and noise ratings to minimize disruption in living spaces.
Choosing the right liquid propane tankless water heater involves balancing flow, efficiency, and installation practicality. For mid-sized homes with several hot-water draws, models offering 7–9 GPM with robust BTU output provide a practical blend of performance and reliability. For households with higher demand or larger homes, stepping up to the 10–11 GPM range can deliver consistent temperatures across multiple fixtures.