Rheem RTGH Series 6.8 GPM Natural Gas Tankless Water Heater Alternatives: 6 Similar Picks Compared
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The rheem rtgh series 6 8 gpm natural gas tankless water heater delivers high efficiency for indoor homes. It provides precise temperature control and reliable performance for households needing steady hot water. This unit suits buyers who prioritize energy savings and compact indoor installation over smart connectivity features.
You might look for alternatives if you need a higher flow rate for larger families. Some homes require outdoor installation or different venting options. The alternatives listed here were chosen because their specifications overlap with the original model. Each pick shares key traits like natural gas fuel and indoor compatibility. This list compares 6 similar picks to help you find the right fit for your specific hot water demands.
Our top pick: Rheem RTGH 6.8 GPM Indoor Natural Gas Tankless Heater.
How each alternative compares
Rheem RTG 9.5 GPM Natural Gas Water Heater
The Rheem RTG 9.5 GPM Natural Gas Water Heater offers a higher flow rate of 9.5 GPM compared to the RTGH’s 6.8 GPM. This makes it better for large homes with simultaneous shower use. It shares the same indoor installation and WiFi features. However, it is non-condensing, which typically means lower efficiency than the RTGH’s condensing technology. The unit is slightly narrower at 13.5 inches wide but heavier. Choose this if you need more hot water volume and do not mind higher gas usage for that capacity.
Westinghouse 9.2 GPM Indoor Natural Gas Tankless Heater
The Westinghouse 9.2 GPM Indoor Natural Gas Tankless Heater provides a significant flow rate increase to 9.2 GPM. It includes WiFi connectivity for remote control, similar to the RTGH. This model is wider at 15.9 inches and taller at 24.8 inches. It suits large households needing high-volume hot water. The RTGH is more compact and likely more energy-efficient due to its condensing design. Pick the Westinghouse if your primary need is maximum flow rate for multiple bathrooms, and you have the space for a larger unit.
MIZUDO 7.9 GPM Natural Gas WiFi Heater
The MIZUDO 7.9 GPM Natural Gas WiFi Heater delivers 7.9 GPM, which is higher than the RTGH’s 6.8 GPM. It features WiFi control and indoor installation. The unit is wider at 16.3 inches and includes a 180,000 BTU input, suggesting higher power. It is lighter at 39.6 pounds. The RTGH offers higher efficiency and precise temperature control. Choose the MIZUDO if you need a moderate flow boost and prefer a lighter, wider unit for your installation space, while accepting potentially lower efficiency.
Rheem IKONIC 10.1 GPM Natural Gas Tankless Water Heater
The Rheem IKONIC 10.1 GPM Natural Gas Tankless Water Heater provides a substantial flow rate of 10.1 GPM. It includes WiFi and recirculation features for water savings. This unit is larger, standing 28.6 inches tall and weighing 86 pounds. It is designed for whole-house use in large households. The RTGH is more compact and efficient. Select the IKONIC if you have ample space and need the highest possible flow rate with smart recirculation capabilities, rather than prioritizing compact size or maximum energy efficiency.
Ranein 4.3 GPM Indoor Natural Gas Tankless Water Heater
The Ranein 4.3 GPM Indoor Natural Gas Tankless Water Heater offers a lower flow rate of 4.3 GPM. It is designed for small households with moderate hot water needs. The unit is wider at 16.9 inches and includes venting. It lacks WiFi features found in the RTGH. The RTGH provides higher capacity and efficiency. Choose the Ranein if you have a small space or low demand, and you want a simpler, preset solution without the need for smart connectivity or high-volume output.
VEVOR 4.3 Gal Natural Gas Tankless Water Heater
The VEVOR 4.3 Gal Natural Gas Tankless Water Heater is a compact unit with a 4.3-gallon capacity. It is designed for single-bathroom precision heating. The unit is smaller, weighing only 19.8 pounds. It lacks WiFi and high-flow capabilities. The RTGH provides endless hot water and higher efficiency. Pick the VEVOR if you need a small, lightweight heater for a single bathroom or tiny home, where high flow rates and smart features are unnecessary. It suits users prioritizing minimal space and basic functionality.
Quick picks
Our 7 picks
Rheem RTGH 6.8 GPM Indoor Natural Gas Tankless Heater
Best for: Indoor homes needing efficient hot water
- Fuel Type
- Natural Gas
- Flow Rate
- 6.8 GPM
- BTU
- 120,000 BTU/hr
- Installation Location
- Indoor
- Temperature Control
- ±1°F
- Certification
- CSA
View on Amazon: Rheem RTGH 6.8 GPM Indoor Natural Gas Tankless Heater Affiliate link
This Rheem unit delivers 6.8 GPM at a 35°F rise, powered by 120,000 BTU/hr. It features a 0.93 UEF and indoor direct-vent installation. The digital LED control offers ±1°F precision. It suits homes with two to three simultaneous showers. The compact 23.7-inch height fits tight spaces. You get endless hot water with high efficiency.
Pros
- 6.8 GPM flow rate for whole-house use
- 0.93 UEF for ultra-low gas bills
- Digital LED control with ±1°F precision
- Indoor direct-vent installation with low NOx emissions
Cons
- No WiFi connectivity in this 6.8 GPM model
- Indoor installation only, not outdoor rated
- Requires professional installation for safety
Good fit if
- You need high efficiency for a multi-bathroom home
- You have indoor venting capability available
- You want precise temperature control without smart features
Skip if
- You require WiFi remote control
- You need outdoor installation options
- You want a flow rate above 6.8 GPM
Verdict: Rheem RTGH 6.8 GPM Natural Gas provides reliable high-efficiency performance for indoor homes. It fits buyers who prioritize energy savings and precise temperature control over smart connectivity.
Rheem RTG 9.5 GPM Natural Gas Water Heater
Best for: Large homes with high hot water demand
- Fuel Type
- Natural Gas
- Flow Rate
- 9.5 GPM
- BTU
- 199,900 BTU/hr
- Installation Location
- Indoor
- Temperature Control
- ±1°F
- Certification
- CSA
View on Amazon: Rheem RTG 9.5 GPM Natural Gas Water Heater Affiliate link
The Rheem RTG Series delivers 9.5 GPM at a 35°F rise with 199,900 BTU/hr output. This indoor unit features a digital LED panel with ±1°F precision and WiFi connectivity. It is designed for whole-house use, supporting 3-4 simultaneous showers. The non-condensing design offers a 0.82 UEF rating. It suits large families needing high flow rates and smart monitoring capabilities.
Pros
- 9.5 GPM flow rate supports multiple simultaneous uses
- 199,900 BTU/hr heating capacity for whole-house demand
- WiFi enabled for remote monitoring and control
- Digital LED display with ±1°F temperature precision
- 0.82 Uniform Energy Factor rating
Cons
- Indoor installation only, requiring venting
- Non-condensing design limits efficiency compared to condensing models
- Heavier build at 46.5 pounds
Good fit if
- You need high flow for 3-4 bathrooms
- You want WiFi connectivity for monitoring
- You are replacing an aging tank heater
Skip if
- You require outdoor installation
- You need a condensing unit for maximum efficiency
- You have limited space for a 24.2-inch height
Verdict: The Rheem RTG 9.5 GPM Natural Gas Tankless is ideal for large homes requiring high capacity and smart features. It fits buyers who prioritize flow rate and digital control over compact size or outdoor versatility.
Westinghouse 9.2 GPM Indoor Natural Gas Tankless Heater
Best for: Large homes needing high flow and smart control
- Fuel Type
- Natural Gas
- Flow Rate
- 10.3 GPM
- BTU
- 199,000 BTU
- Installation Location
- Indoor
- Temperature Control
- ±1.8°F
- Certification
- CSA
View on Amazon: Westinghouse 9.2 GPM Indoor Natural Gas Tankless Heater Affiliate link
This indoor natural gas unit delivers 9.2 GPM and 199,000 BTU for whole-home use. It maintains temperature stability within ±1.8°F and includes smart WiFi app control. The design features freeze protection down to -13°F and a copper heat exchanger. It suits large households needing high flow rates and remote management capabilities for their water heating system.
Pros
- 9.2 GPM flow rate for multiple bathrooms
- 199,000 BTU heating capacity
- Smart WiFi app and voice control
- ±1.8°F temperature stability
- Freeze protection down to -13°F
Cons
- Heavier at 56.7 pounds
- Requires 3" x 5" double-wall vent pipe
- Indoor installation only
Good fit if
- You need high flow for 4+ bathrooms
- You want remote temperature adjustments via app
- You require freeze protection for cold climates
Skip if
- You need outdoor installation
- You prefer propane fuel
- You lack space for double-wall venting
Verdict: Westinghouse 9.2 GPM WiFi Gas Heater offers robust performance for large homes requiring precise temperature control and smart connectivity. It is an ideal fit for households prioritizing high flow rates and remote management over compact sizing.
MIZUDO 7.9 GPM Natural Gas WiFi Heater
Best for: Multi-fixture indoor use with app control
- Fuel Type
- Natural Gas
- Flow Rate
- Up to 7.9 GPM
- BTU
- 180,000 BTU/h
- Installation Location
- Indoor
- Voltage
- 120V AC
- Temperature Control
- 95 to 149°F, ±1°F
View on Amazon: MIZUDO 7.9 GPM Natural Gas WiFi Heater Affiliate link
This indoor natural gas unit delivers 7.9 GPM with 180,000 BTU/h input. It features WiFi control for remote temperature adjustments and maintains stability within ±1°F. The sealed combustion system draws air from outside, ensuring safe indoor installation. It suits larger households needing simultaneous hot water across multiple fixtures, provided you have the necessary gas and venting infrastructure.
Pros
- 7.9 GPM flow rate for multiple fixtures
- WiFi app control for remote monitoring
- ±1°F temperature stability
- Sealed combustion for indoor safety
Cons
- 2-year unit warranty is shorter than competitors
- Requires 3-in/5-in concentric direct vent
- Heavier at 39.6 pounds
Good fit if
- You need high flow for 3-5 draw points
- You want remote temperature control via app
- You have indoor direct-vent capability
Skip if
- You need a 5-year unit warranty
- You are installing outdoors
- You prefer propane fuel
Verdict: MIZUDO 7.9 GPM Natural Gas WiFi Heater offers precise temperature control and high capacity for busy homes, but its shorter warranty and specific venting needs limit its appeal for those seeking long-term simplicity.
Rheem IKONIC 10.1 GPM Natural Gas Tankless Water Heater
Best for: Whole-house hot water with smart controls
- Fuel Type
- Natural Gas
- Flow Rate
- 10.1 GPM
- BTU
- 180,000 BTUs
- Installation Location
- Indoor
- Dimensions
- 28.6 x 17.3 x 13.7 inches
- Features
- WiFi
View on Amazon: Rheem IKONIC 10.1 GPM Natural Gas Tankless Water Heater Affiliate link
This Rheem unit delivers 10.1 GPM of hot water using 180,000 BTUs of natural gas power. It features built-in EcoNet Wi-Fi for remote control and a recirculation system to save water. The compact design allows for flexible indoor installation with minimal side clearance. It includes hot-start programming to maintain ready water temperature between uses.
Pros
- 10.1 GPM flow rate for whole-house supply
- 180,000 BTU high-efficiency condensing technology
- Built-in EcoNet Wi-Fi for mobile control
- Customizable recirculation saves average 11,000 gallons yearly
Cons
- Limited to indoor installation only
- 86-pound weight requires sturdy mounting
- Outdoor use requires separate conversion kit
Good fit if
- You need high flow for multiple simultaneous uses
- You want remote temperature and usage control
- You have space for an indoor unit
Skip if
- You require outdoor installation without extra kits
- You need a portable or compact unit under 50 pounds
- You prefer a non-condensing standard efficiency model
Verdict: Rheem IKONIC 10.1 GPM Natural Gas suits large households needing high-volume hot water with smart monitoring. Its Wi-Fi integration and recirculation features make it ideal for homes prioritizing water savings and remote management.
Ranein 4.3 GPM Indoor Natural Gas Tankless Water Heater
Best for: small indoor installations with moderate hot water needs
- Fuel Type
- Natural Gas
- Flow Rate
- 4.3 GPM
- BTU
- 100,000 BTU
- Installation Location
- Indoor
- Temperature Control
- 95°F-155°F
- Dimensions
- 25.6 x 16.9 x 16.9 inches
View on Amazon: Ranein 4.3 GPM Indoor Natural Gas Tankless Water Heater Affiliate link
This Ranein unit delivers 4.3 GPM at 100,000 BTU for indoor natural gas installation. It features an oxygen-free copper heat exchanger and four preset modes for kitchen, shower, and bath use. The LED display shows real-time temperature and fault codes. Anti-freeze protection handles temperatures down to 14°F. It includes a vent pipe for straightforward setup.
Pros
- 4.3 GPM flow rate supports 3-4 water points
- 100,000 BTU heating power
- Oxygen-free copper heat exchanger
- Four intelligent preset modes
- Includes vent pipe for indoor use
Cons
- Lower 4.3 GPM flow rate compared to 6.8+ GPM alternatives
- Indoor installation only
- Not rated for elevations above 2,000 feet
Good fit if
- You need a compact indoor unit for a single bathroom or kitchen
- You want preset modes for specific fixtures
- You prefer a unit that includes the vent pipe
Skip if
- You require more than 4.3 GPM for whole-house use
- You live at an elevation above 2,000 feet
- You need an outdoor-rated unit
Verdict: Ranein 4.3 GPM Natural Gas Indoor Heater suits small households needing reliable indoor heating with included venting. It fits buyers prioritizing preset convenience over high-volume flow.
VEVOR 4.3 Gal Natural Gas Tankless Water Heater
Best for: single bathroom precision heating
- Fuel Type
- Gas
- BTU
- 100,000 BTU/hr
- Installation Location
- Indoor
- Capacity
- 4.3 Gal
- Temperature Control
- ±1°F
- Dimensions
- 21.7 x 13.8 x 13.8 inches
View on Amazon: VEVOR 4.3 Gal Natural Gas Tankless Water Heater Affiliate link
This VEVOR unit delivers 100,000 BTU/hr of heating power for indoor use. It holds a 4.3-gallon capacity and maintains temperature within ±1°F. The silver-gray design includes an LED display for real-time monitoring. You get multiple safety protections against overheating or leaks. This compact heater suits small households needing reliable, instant hot water without large storage tanks.
Pros
- 100,000 BTU/hr heating output
- ±1°F precise temperature control
- LED display shows real-time data
- Multiple safety protections included
Cons
- 4.3-gallon capacity limits whole-house use
- No WiFi or smart app mentioned
- Indoor installation only
Good fit if
- You need precise temperature stability
- You want a compact indoor unit
- You prioritize safety features
Skip if
- You require whole-house flow for multiple baths
- You need remote smart control
- You want outdoor installation
Verdict: VEVOR 4.3 Gal Gas Tankless Heater offers stable heat and safety for small homes. It fits single-bathroom setups where precision matters more than high flow rates.
Specifications side by side
| Spec | Rheem RTGH 6.8 GPM Indoor Natural Gas Tankless Heater | Rheem RTG 9.5 GPM Natural Gas Water Heater | Westinghouse 9.2 GPM Indoor Natural Gas Tankless Heater | MIZUDO 7.9 GPM Natural Gas WiFi Heater | Rheem IKONIC 10.1 GPM Natural Gas Tankless Water Heater | Ranein 4.3 GPM Indoor Natural Gas Tankless Water Heater | VEVOR 4.3 Gal Natural Gas Tankless Water Heater |
|---|---|---|---|---|---|---|---|
| Fuel Type | Natural Gas | Natural Gas | Natural Gas | Natural Gas | Natural Gas | Natural Gas | Gas |
| Flow Rate | 6.8 GPM | 9.5 GPM | 10.3 GPM | Up to 7.9 GPM | 10.1 GPM | 4.3 GPM | not stated |
| BTU | 120,000 BTU/hr | 199,900 BTU/hr | 199,000 BTU | 180,000 BTU/h | 180,000 BTUs | 100,000 BTU | 100,000 BTU/hr |
| Installation Location | Indoor | Indoor | Indoor | Indoor | Indoor | Indoor | Indoor |
| Capacity | not stated | not stated | not stated | not stated | not stated | not stated | 4.3 Gal |
| Voltage | not stated | not stated | not stated | 120V AC | not stated | not stated | not stated |
| Temperature Control | ±1°F | ±1°F | ±1.8°F | 95 to 149°F, ±1°F | not stated | 95°F-155°F | ±1°F |
| Certification | CSA | CSA | CSA | CSA | not stated | not stated | not stated |
| Dimensions | 23.7 x 17.7 x 9.8 inches | 24.2 x 13.5 x 10.3 inches | not stated | 25 x 16.3 x 7.3 in | 28.6 x 17.3 x 13.7 inches | 25.6 x 16.9 x 16.9 inches | 21.7 x 13.8 x 13.8 inches |
| Use | not stated | not stated | Whole House | not stated | not stated | Whole House | Whole House |
| Venting Type | not stated | Non-Condensing | not stated | not stated | not stated | not stated | not stated |
| Features | WiFi | WiFi | WiFi | WiFi | WiFi | not stated | not stated |
| Weight | 59.9 pounds | 46.5 pounds | 56.7 pounds | 39.6 pounds | 86 pounds | not stated | 19.8 pounds |
| Size | 6.8 GPM (No WiFi) | 9.5 GPM (WiFi) | not stated | Natural Gas, 7.9 GPM, 180,000 BTU, Indoor | 10.1 GPM (w Recirc) | 4.3 GPM Indoor | 4.3 Gal |
| Color | Gray | Gray | Grey 103NI | White 7.9N | Gray | Gray-NG | Silver Gray |
| Model | RTGH-68DVLN-3 | RTG-95DVELN-3 | HW199A0G-NG | HW180A0W-NG | RECTGH-SR10iN | RH10K | JSQ30-A |
If you plan an outdoor fuel line, you can compare the best natural gas patio heaters by rated heat output.
Frequently asked questions
What is the best alternative to the Rheem RTGH 6.8 GPM for large homes?
The Rheem RTG 9.5 GPM Natural Gas Water Heater is the top choice for large households. It delivers a higher flow rate of 9.5 GPM compared to the RTGH’s 6.8 GPM. This extra capacity handles simultaneous shower use better. It also features WiFi connectivity for remote monitoring and control.
Does the Rheem RTGH 6.8 GPM support smart home integration?
Yes, the Rheem RTGH 6.8 GPM includes WiFi capabilities. You can monitor and control the unit remotely via a smartphone app. This feature allows you to adjust settings and check status from anywhere, adding convenience to your daily hot water management.
Which tankless heater offers the highest flow rate in this list?
The Rheem IKONIC 10.1 GPM Natural Gas Tankless Water Heater provides the highest flow rate at 10.1 GPM. It is designed for whole-house hot water needs. The unit also includes recirculation features to save water and maintain consistent temperatures throughout your home.
Is there a compact option for small indoor installations?
The Ranein 4.3 GPM Indoor Natural Gas Tankless Water Heater is ideal for small spaces. It offers a moderate flow rate suitable for single-bathroom setups. The unit is designed for indoor installation and provides reliable heating without requiring excessive floor or wall space.
Can I use WiFi with the Westinghouse 9.2 GPM heater?
Yes, the Westinghouse 9.2 GPM Indoor Natural Gas Tankless Heater features WiFi connectivity. You can manage temperature settings and monitor performance remotely. This smart control is useful for large homes needing precise hot water management and energy efficiency.
What is the smallest unit available for single bathroom use?
The VEVOR 4.3 Gal Natural Gas Tankless Water Heater is the smallest option listed. It provides stable heat for single-bathroom precision heating. The compact design fits well in tight spaces while delivering reliable performance for households with moderate hot water demands.
Does the MIZUDO 7.9 GPM heater include WiFi?
Yes, the MIZUDO 7.9 GPM Natural Gas WiFi Heater includes WiFi functionality. You can control the unit remotely for precise temperature adjustments. This feature is helpful for busy homes needing to manage hot water usage efficiently across multiple fixtures.