Rheem 8.4 GPM Indoor Propane Tankless Water Heater Alternatives: 6 Similar Picks Compared
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You are looking for rheem 8 4 gpm indoor propane tankless water heater alternatives that match the high output of the Rheem RTG Series. This unit delivers 8.4 GPM at a 35°F rise with 180,000 BTUs, making it suitable for whole-house use in large families. Its indoor installation and digital LED control offer precision within ±1°F. However, you might need a different fuel type, such as natural gas, or an outdoor model for exterior mounting. Some buyers also prefer smaller footprints or higher efficiency ratings than the standard non-condensing design provides.
The 6 alternatives listed here share key specifications with the original, ensuring comparable performance. You will find options with similar flow rates but varying dimensions, weights, and venting requirements. Some picks offer WiFi connectivity for remote monitoring, while others focus on compact sizing for tight spaces. Others provide natural gas compatibility for homes without propane access. Each selection is chosen because its core specs overlap with the Rheem RTG, allowing you to compare practical differences in size, efficiency, and features without sacrificing hot water capacity.
Our top pick: Rheem 8.4 GPM Indoor Propane Tankless Water Heater.
How Each Alternative Compares
Rheem RTG 8.4 GPM Outdoor Propane Tankless Water Heater
The Rheem RTG 8.4 GPM Outdoor Propane model shares the same 8.4 GPM flow rate and propane fuel source as the original. It differs by being designed for outdoor installation, which removes the need for indoor venting. The unit is slightly shorter at 20.8 inches tall and lighter at 39.3 pounds, making it easier to mount on an exterior wall. It retains the non-condensing venting type and WiFi connectivity. If your home lacks indoor venting options or you prefer keeping the heater outside, this version provides the same high output without the indoor space requirements.
Rinnai RE160iP 6.6 GPM Propane Indoor
The Rinnai RE160iP 6.6 GPM Propane Indoor unit offers a lower flow rate of 6.6 GPM compared to the original’s 8.4 GPM. This reduction means it may struggle to supply multiple simultaneous showers in very large homes. However, it is a strong choice for compact indoor installations where space is limited. It shares the indoor propane and non-condensing venting specifications. The unit is slightly taller at 27.3 inches but has a similar width. If you do not need the maximum flow rate of the Rheem model and want a reliable indoor propane solution for a smaller household, this compact alternative is a practical option.
Rheem RTG 8.4 GPM Indoor Natural Gas Water Heater
The Rheem RTG 8.4 GPM Indoor Natural Gas model matches the original in flow rate, indoor installation, and physical dimensions. The key difference is the fuel type. This unit runs on natural gas instead of liquid propane. It maintains the same 8.4 GPM capacity and non-condensing venting design. If your home is connected to a natural gas line rather than a propane tank, this model provides identical performance and hot water delivery. It is the direct alternative for users who need the same high output but have natural gas infrastructure instead of propane.
Rheem RTG 8.4 GPM Outdoor Natural Gas Tankless Heater
The Rheem RTG 8.4 GPM Outdoor Natural Gas Tankless Heater combines the high flow rate of the original with outdoor placement. It delivers 8.4 GPM using natural gas instead of propane. The unit is designed for outdoor installation, which simplifies venting requirements. It shares the same compact width and non-condensing venting type. This model is ideal for homes with natural gas access that prefer outdoor units. It offers the same whole-house capacity as the original but adapts to different fuel sources and outdoor mounting needs for users who do not require indoor propane heating.
Rheem RTGH Series 8.4 GPM Indoor Propane
The Rheem RTGH Series 8.4 GPM Indoor Propane unit matches the original in flow rate and fuel type. It is designed for indoor installation with propane. However, it is wider at 17.7 inches and heavier at 59.9 pounds, making it bulkier than the original. It retains the 8.4 GPM capacity and indoor propane specifications. This model is suitable for homes that need the same high output but have the space for a slightly larger unit. It provides the same hot water performance for whole-house use, prioritizing capacity over the compact footprint of the standard RTG model.
Rheem IKONIC 8.4 GPM Propane Tankless Heater
The Rheem IKONIC 8.4 GPM Propane Tankless Heater offers the same 8.4 GPM flow rate and indoor propane capability as the original. It is significantly larger, measuring 28.6 inches tall and weighing 86 pounds. This model includes recirculation features, which the original does not specify. It is designed for homes prioritizing smart control and water savings over compact size. The unit maintains the high output for whole-house use. If you need advanced remote management and recirculation capabilities alongside high flow rates, this larger model provides those features while delivering the same hot water volume as the original.
Quick picks
Our 7 picks
Rheem 8.4 GPM Indoor Propane Tankless Water Heater
Best for: Indoor whole-house propane hot water
- Fuel Type
- Liquid Propane
- Flow Rate
- 8.4 GPM at 35°F rise
- BTU
- 180,000 BTU/hr
- Installation Location
- Indoor
- Temperature Control
- Digital LED, ±1°F
- Certification
- CSA
View on Amazon: Rheem 8.4 GPM Indoor Propane Tankless Water Heater Affiliate link
This Rheem RTG unit delivers 8.4 GPM at a 35°F rise using 180,000 BTU/hr of liquid propane power. Its non-condensing design offers an 0.82 UEF, saving energy compared to traditional tank heaters. The digital LED panel allows ±1°F precision control. It is built for indoor wall-mount installation and includes freeze protection. This model suits homes needing reliable whole-house hot water for multiple simultaneous fixtures.
Pros
- 8.4 GPM flow rate supports 3-4 showers
- 180,000 BTU/hr output for high demand
- 0.82 UEF energy efficiency rating
- Digital LED control with ±1°F precision
- 15-year heat exchanger warranty
Cons
- Indoor installation only requires professional setup
- Non-condensing design may be less efficient than condensing models
- No WiFi connectivity in this specific 8.4 GPM variant
Good fit if
- You need high flow for multiple bathrooms
- You have an indoor propane gas line
- You want precise temperature control
Skip if
- You require outdoor installation
- You prefer natural gas over propane
- You want smart home integration
Verdict: Rheem RTG 8.4 GPM Indoor Propane is a high-output choice for large families with indoor propane access. It fits homes prioritizing flow rate and precision over smart features. Buyers needing outdoor units or natural gas should look elsewhere.
Rheem RTG 8.4 GPM Outdoor Propane Tankless Water Heater
Best for: Outdoor whole-house propane hot water
- Fuel Type
- Liquid Propane
- Flow Rate
- 8.4 GPM at 35°F rise
- BTU
- 180,000 BTU/hr
- Installation Location
- Outdoor
- Temperature Control
- Digital LED, ±1°F
- Certification
- CSA
View on Amazon: Rheem RTG 8.4 GPM Outdoor Propane Tankless Water Heater Affiliate link
This outdoor propane unit delivers 8.4 GPM at a 35°F rise, powered by 180,000 BTUs. It features a non-condensing design with a 0.82 UEF rating. You get digital LED control with ±1°F precision and built-in freeze protection. The gray metal cabinet mounts easily to walls. It suits large families needing whole-house hot water for outdoor installation.
Pros
- 8.4 GPM flow rate for 3-4 simultaneous showers
- 180,000 BTU/hr output for high performance
- Digital LED panel with ±1°F temperature adjustment
- 0.82 UEF energy efficiency rating
- Built-in freeze and flame failure protection
Cons
- Requires outdoor installation only
- Non-condensing design limits efficiency compared to condensing models
- No WiFi connectivity listed in specifications
Good fit if
- You need an outdoor propane water heater
- You want precise digital temperature control
- You require high flow for multiple bathrooms
Skip if
- You need indoor installation
- You prefer natural gas over propane
- You require WiFi smart home integration
Verdict: Rheem RTG 8.4 GPM Propane Outdoor Heater fits outdoor homes needing high-capacity hot water. It offers precise control and robust safety features for whole-house use.
Rinnai RE160iP 6.6 GPM Propane Indoor
Best for: compact indoor propane installations
- Fuel Type
- Propane
- Flow Rate
- 6.6 GPM
- BTU
- 160k BTU
- Installation Location
- Indoor
- Dimensions
- 27.3 x 14.1 x 10.8 in
- Venting Type
- Non-Condensing
View on Amazon: Rinnai RE160iP 6.6 GPM Propane Indoor Affiliate link
The Rinnai RE160iP delivers 6.6 GPM of hot water for indoor propane use. Its compact 14.1 by 10.8 by 27.3-inch footprint fits tight spaces. The unit weighs 48.5 pounds and features a non-condensing design. You get a 15-year heat exchanger warranty. This model suits homes needing reliable indoor heating without the bulk of larger units.
Pros
- 6.6 GPM flow rate supports multiple fixtures
- Compact 14.1 x 10.8 x 27.3 inch size
- 15-year heat exchanger warranty
- Non-condensing indoor propane design
- LED screen shows error codes
Cons
- Lower 6.6 GPM flow rate compared to 8.4 GPM competitors
- WiFi control module sold separately
- Professional installation required
Good fit if
- You need a compact indoor propane unit
- You want a 15-year heat exchanger warranty
- You have moderate hot water demands
Skip if
- You require 8.4 GPM or higher flow
- You want built-in WiFi control
- You need an outdoor installation model
Verdict: Rinnai RE160iP 6.6 GPM Indoor Propane fits buyers prioritizing warranty coverage and compact indoor sizing over maximum flow rate.
Rheem RTG 8.4 GPM Indoor Natural Gas Water Heater
Best for: Whole-house natural gas heating
- Fuel Type
- Natural Gas
- Flow Rate
- 8.4 GPM
- BTU
- 180,000 BTU/hr
- Installation Location
- Indoor
- Temperature Control
- ±1°F
- Certification
- CSA
View on Amazon: Rheem RTG 8.4 GPM Indoor Natural Gas Water Heater Affiliate link
This Rheem unit delivers 8.4 GPM of hot water using natural gas. It features 180,000 BTU/hr output and a 0.82 UEF rating. The indoor, non-condensing design saves space with a wall-mount build. Digital controls allow ±1°F precision. It suits homes needing reliable whole-house heating without the bulk of a traditional tank.
Pros
- 8.4 GPM flow rate supports 3-4 simultaneous showers
- 0.82 UEF efficiency saves energy vs. tank heaters
- Digital LED panel with ±1°F temperature precision
- Built-in freeze and flame failure protection
Cons
- Indoor installation requires specific venting setup
- Non-condensing design may have higher exhaust temps
- Professional installation is mandatory
Good fit if
- You need high flow for multiple bathrooms
- You have existing natural gas lines
- You want indoor wall-mount convenience
Skip if
- You require outdoor installation only
- You prefer propane fuel source
- You want DIY-friendly setup
Verdict: Rheem RTG Series 8.4 GPM Indoor Natural Gas provides steady hot water for large households with efficient gas heating. It fits homes with natural gas access and indoor venting capabilities.
Rheem RTG 8.4 GPM Outdoor Natural Gas Tankless Heater
Best for: outdoor whole-house hot water demand
- Fuel Type
- Natural Gas
- Flow Rate
- 8.4 GPM
- BTU
- 180,000 BTU/hr
- Installation Location
- Outdoor
- Temperature Control
- ±1°F
- Certification
- CSA
View on Amazon: Rheem RTG 8.4 GPM Outdoor Natural Gas Tankless Heater Affiliate link
This Rheem RTG unit delivers 8.4 GPM at a 35°F rise using natural gas. It outputs 180,000 BTU/hr for whole-house hot water. The non-condensing design requires outdoor installation only. It features a digital LED panel with ±1°F precision. The gray metal cabinet is CSA certified. It suits large families needing reliable, endless hot water without tank storage.
Pros
- 8.4 GPM flow rate supports 3-4 simultaneous showers
- 180,000 BTU/hr high output for fast heating
- Digital LED control with ±1°F temperature precision
- Built-in freeze and flame failure protection
- Non-condensing design eliminates complex venting
Cons
- Outdoor installation only, not suitable for indoor use
- No WiFi connectivity despite variation options
- Requires professional installation for safety compliance
Good fit if
- You need a dedicated outdoor water heater for a large home
- You want precise temperature control without tank storage
- You have access to natural gas and outdoor mounting space
Skip if
- You require indoor installation due to space constraints
- You need smart home integration or remote monitoring
- You are looking for a propane-fueled unit
Verdict: Rheem RTG 8.4 GPM Outdoor Natural Gas Heater provides consistent high-volume hot water for outdoor setups. It is ideal for large households with natural gas access who prioritize durability and precise temperature control over smart features.
Rheem RTGH Series 8.4 GPM Indoor Propane
Best for: Indoor propane homes needing high efficiency
- Fuel Type
- Liquid Propane
- Flow Rate
- 8.4 GPM at 35°F rise
- BTU
- 157,000 BTU/hr
- Installation Location
- Indoor
- Temperature Control
- Digital LED, ±1°F
- Certification
- CSA
View on Amazon: Rheem RTGH Series 8.4 GPM Indoor Propane Affiliate link
This Rheem unit delivers 8.4 GPM at a 35°F rise using liquid propane. It features 157,000 BTU/hr output and a 0.93 UEF due to condensing technology. The digital LED control offers ±1°F precision. It is designed for indoor direct-vent installation. This model suits multi-bathroom homes needing reliable whole-house hot water without WiFi connectivity.
Pros
- 8.4 GPM flow rate at 35°F rise
- 0.93 Uniform Energy Factor for high efficiency
- Digital LED temperature control with ±1°F precision
- 15-year heat exchanger warranty
Cons
- Indoor installation requires direct venting
- No WiFi connectivity included
- 59.9 pounds weight requires sturdy mounting
Good fit if
- You need high-efficiency condensing technology
- You require precise digital temperature control
- You have an indoor space for direct venting
Skip if
- You prefer outdoor installation options
- You want built-in WiFi monitoring
- You need a lighter unit for easy mounting
Verdict: Rheem RTGH 8.4 GPM Propane is a high-efficiency indoor heater for homes needing precise temperature control and strong flow rates without smart features.
Rheem IKONIC 8.4 GPM Propane Tankless Heater
Best for: indoor propane homes needing smart control
- Fuel Type
- Liquid Propane
- Flow Rate
- 8.4 GPM
- BTU
- 157,000 BTU/hr
- Installation Location
- Indoor
- Dimensions
- 28.6 x 17.3 x 13.7 inches
- Features
- WiFi
View on Amazon: Rheem IKONIC 8.4 GPM Propane Tankless Heater Affiliate link
This Rheem IKONIC unit delivers 8.4 GPM of hot water using liquid propane. It features a 157,000 BTU burner and includes built-in EcoNet Wi-Fi for remote control. The compact design allows for flexible indoor installation. You get energy savings through customizable recirculation settings. This model suits homes needing reliable, high-efficiency indoor heating for multiple fixtures.
Pros
- 8.4 GPM flow rate for whole-house coverage
- 157,000 BTU/hr output for consistent heat
- Built-in EcoNet Wi-Fi for app control
- Customizable recirculation saves water and energy
- Ultra-low NOx burner for sustainability
Cons
- Indoor installation only without conversion kit
- Heavier build at 86 pounds
- Larger footprint than non-condensing models
Good fit if
- You need indoor propane heating with smart features
- You want to reduce water waste via recirculation
- You prefer high-efficiency condensing technology
Skip if
- You require outdoor-only installation
- You need a lighter unit for easy mounting
- You prefer non-condensing simplicity
Verdict: Rheem IKONIC 8.4 GPM Propane Indoor offers smart control and high efficiency for indoor propane users. It fits homes prioritizing water savings and remote management over compact size.
Specifications side by side
| Spec | Rheem 8.4 GPM Indoor Propane Tankless Water Heater | Rheem RTG 8.4 GPM Outdoor Propane Tankless Water Heater | Rinnai RE160iP 6.6 GPM Propane Indoor | Rheem RTG 8.4 GPM Indoor Natural Gas Water Heater | Rheem RTG 8.4 GPM Outdoor Natural Gas Tankless Heater | Rheem RTGH Series 8.4 GPM Indoor Propane | Rheem IKONIC 8.4 GPM Propane Tankless Heater |
|---|---|---|---|---|---|---|---|
| Fuel Type | Liquid Propane | Liquid Propane | Propane | Natural Gas | Natural Gas | Liquid Propane | Liquid Propane |
| Flow Rate | 8.4 GPM at 35°F rise | 8.4 GPM at 35°F rise | 6.6 GPM | 8.4 GPM | 8.4 GPM | 8.4 GPM at 35°F rise | 8.4 GPM |
| BTU | 180,000 BTU/hr | 180,000 BTU/hr | 160k BTU | 180,000 BTU/hr | 180,000 BTU/hr | 157,000 BTU/hr | 157,000 BTU/hr |
| Installation Location | Indoor | Outdoor | Indoor | Indoor | Outdoor | Indoor | Indoor |
| Temperature Control | Digital LED, ±1°F | Digital LED, ±1°F | not stated | ±1°F | ±1°F | Digital LED, ±1°F | not stated |
| Certification | CSA | CSA | not stated | CSA | CSA | CSA | not stated |
| Dimensions | 24.2 x 13.5 x 10.3 inches | 20.8 x 13.5 x 9.4 inches | 27.3 x 14.1 x 10.8 in | 24.2 x 13.5 x 10.3 inches | 20.8 x 13.5 x 9.4 inches | 23.7 x 17.7 x 9.8 inches | 28.6 x 17.3 x 13.7 inches |
| Venting Type | Non-Condensing | Non-Condensing | Non-Condensing | Non-Condensing | Non-Condensing | not stated | not stated |
| Features | WiFi | WiFi | not stated | not stated | WiFi | WiFi | WiFi |
| Weight | 46.5 pounds | 39.3 pounds | 48.5 pounds | 46.5 pounds | 39.3 pounds | 59.9 pounds | 86 pounds |
| Size | 8.4 GPM (No WiFi) | 8.4 GPM (Non-WiFi) | 6.6 GPM | 8.4 GPM (Standard) | 8.4 GPM (No WiFi) | 8.4 GPM (Without WiFi) | 8.4 GPM (w Recirc) |
| Color | Gray | Gray | Silver | Gray | Gray | Gray | Gray |
| Model | RTG-84DVLP-3 | RTG-84XLP-3 | REU-VE2125FFD-US-P | RTG-84DVLN-3 | RTG-84XLN-3 | RTGH-84DVLP-3 | RECTGH-SR84iP |
Frequently asked questions
Can I use these 8.4 GPM units in a small apartment?
You should consider your hot water demand carefully. An 8.4 GPM flow rate is designed for whole-house use in large families. Smaller spaces typically need lower flow rates, such as 2.5 GPM. Using a high-output unit in a small apartment may lead to unnecessary energy consumption. Check your fixture count before choosing a high-capacity model.
Do all these propane models require indoor venting?
No. Some models like the Rheem RTG 8.4 GPM Outdoor Propane are built for exterior installation. These outdoor units do not need indoor venting systems. Other models, such as the Rheem RTG 8.4 GPM Indoor Propane, are designed for indoor use and require specific non-condensing venting. Verify the installation location for each unit.
Which alternative is best for outdoor installation?
The Rheem RTG 8.4 GPM Outdoor Propane is the top choice for exterior setups. It delivers the same 8.4 GPM flow rate as the indoor version. Its design allows for outdoor placement without indoor venting requirements. This makes it ideal for homes where indoor space is limited or where exterior access is easier.
Are there options if my home uses natural gas instead of propane?
Yes. The Rheem RTG 8.4 GPM Indoor Natural Gas model provides the same 8.4 GPM output. It uses natural gas fuel instead of propane. The dimensions and indoor venting requirements are similar to the propane indoor unit. This allows you to maintain high flow rates while switching fuel sources.
Do these high-flow heaters support smart home integration?
Several models include WiFi capabilities for remote management. The Rheem RTG 8.4 GPM Indoor Propane and Outdoor Propane both feature WiFi. The Rheem IKONIC 8.4 GPM Propane also offers smart control. These features allow you to monitor and adjust settings remotely. Not all models include this technology, so check the specific attributes.
How much space does a 6.6 GPM unit take compared to 8.4 GPM models?
The Rinnai RE160iP 6.6 GPM is slightly taller but similar in width. It measures 27.3 inches in height and 14.1 inches in width. In contrast, the Rheem 8.4 GPM Indoor Propane is 24.2 inches tall and 13.5 inches wide. Both fit standard indoor spaces. Consider your available wall space when choosing between flow rates.
Is there a high-efficiency option for propane users?
The Rheem RTGH 8.4 GPM Indoor Propane is designed for high efficiency. It delivers 8.4 GPM with precise temperature control. This model is suitable for homes needing strong flow rates without smart features. It maintains a compact indoor footprint while optimizing energy use for consistent hot water delivery.