Best Natural Gas Tankless Water Heaters: 15 Spec-Based Picks
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Finding the best natural gas tankless water heaters requires matching burner capacity and flow rates to your home setup. We compared 15 models using the specifications published on their product listings. The VEVOR 4.3 Gal Natural Gas Tankless Water Heater leads the ranking because its 100,000 BTU output and ±1°F temperature regulation suit moderate indoor whole-house installations.
This guide helps you identify the proper heating capacity, flow rate, and venting configuration for your specific household layout.
Quick picks
The best fit for you
- You need standard indoor heating for a whole house VEVOR 4.3 Gal Natural Gas Tankless Water Heater The unit pairs a 100,000 BTU output with precise ±1°F temperature control for whole-home indoor setups.
- You need maximum simultaneous flow across multiple indoor bathrooms Rheem RTG 9.5 GPM Natural Gas Water Heater Its 9.5 GPM flow rate and 199,900 BTU output supply multiple fixtures at once with WiFi connectivity.
- You want outdoor mounting to save indoor living space Rinnai 7.6 GPM Outdoor Natural Gas Water Heater This exterior-mounted heater delivers a 7.6 GPM flow rate without taking up interior utility room space.
- You need modest heating for a single fixture Thermomate 3.06 GPM Natural Gas Tankless Water Heater Its 3.06 GPM flow rate provides steady hot water tailored for smaller homes and point-of-use fixtures.
Our 15 picks
VEVOR 4.3 Gal Natural Gas Tankless Water Heater
Best for: moderate indoor whole-house natural gas setups
- Fuel Type
- Natural Gas (what this guide is about)
- 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
This indoor natural gas tankless water heater delivers up to 4.3 gallons of hot water capacity powered by a 100,000 BTU per hour burner. You get precise temperature management within plus or minus 1°F via an integrated LED touch screen. Its compact 19.8-pound frame connects through standard 1/2-inch NPT fittings, making it a practical whole-house choice if you run moderate simultaneous hot water demands indoors.
Pros
- Provides 100,000 BTU/hr heating output with 4.3-gallon capacity
- Maintains water temperature within ±1°F of setting
- Equipped with an LED touch screen for real-time monitoring
- Uses standard 1/2-inch NPT connections with direct vent compatibility
Cons
- Restricted to indoor installation only
- Capped at 100,000 BTU/hr heating capacity
Good fit if
- You need an indoor natural gas heater delivering up to 4.3 gallons of hot water.
- You want consistent temperature regulation within ±1°F.
- You have existing 1/2-inch NPT pipe connections and indoor direct venting.
Skip if
- You require an outdoor installation.
- You need higher output than 100,000 BTU/hr for heavy simultaneous usage.
Verdict: VEVOR 4.3 Gal 100,000 BTU Natural Gas Water Heater balances a 100,000 BTU/hr output with tight ±1°F temperature regulation. It provides dependable whole-house indoor heating for setups utilizing standard 1/2-inch NPT connections.
VancEpic 4.8 GPM Natural Gas Tankless Heater
Best for: indoor whole-house use up to 5 outlets
- Fuel Type
- Natural Gas (what this guide is about)
- Flow Rate
- 4.8 GPM
- BTU
- 110,000 BTU
- Installation Location
- Indoor
- Temperature Control
- ±1°F
- Dimensions
- 24.6 x 14.4 x 14.4 in
View on Amazon: VancEpic 4.8 GPM Natural Gas Tankless Heater
This VancEpic indoor unit runs on natural gas, delivering up to 4.8 GPM and 110,000 BTU. It features an oxygen-free copper heat exchanger, non-condensing venting, and temperature control within plus or minus 1°F. If you need whole-house hot water across three to five outlets simultaneously, this 25.4-pound model fits standard half-inch NPT plumbing and gives you four preset modes with built-in freeze protection.
Pros
- 4.8 GPM flow rate backed by 110,000 BTU heating capacity
- Water temperature stability maintained within ±1°F
- Oxygen-free copper heat exchanger for thermal transfer
- Four preset temperature modes with an integrated child lock
- Brushless DC negative-pressure exhaust with freeze protection
Cons
- Restricted to indoor non-condensing venting setups
- Uses 1/2-inch NPT connections rather than larger 3/4-inch fittings
- Warranty coverage is limited to 2 years
Good fit if
- You need to supply hot water for 3 to 5 outlets simultaneously.
- You have an indoor installation space with a natural gas supply line.
- You want precise ±1°F temperature stability and multiple preset modes.
Skip if
- You need an outdoor-rated water heater.
- You require a condensing venting setup.
- You need a flow rate greater than 4.8 GPM.
Verdict: VancEpic 4.8 GPM Natural Gas Tankless Heater provides 110,000 BTU output and tight ±1°F regulation for homes requiring 3 to 5 points of use. Its oxygen-free copper heat exchanger and non-condensing configuration make it a solid indoor mid-capacity choice.
Ranein 4.3 GPM Indoor Natural Gas Tankless Water Heater
Best for: Indoor setups below 2,000 feet elevation
- Fuel Type
- Natural Gas (what this guide is about)
- 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
The Ranein indoor natural gas tankless water heater delivers up to 4.3 GPM with a 100,000 BTU heating output, designed to run three to four water fixtures at once. It features an oxygen-free copper heat exchanger, water temperatures from 95°F to 155°F, and four preset modes including kitchen and bathtub filling. An included vent pipe simplifies setup if you need indoor hot water below 2,000 feet.
Pros
- Delivers 4.3 GPM with a 100,000 BTU heating capacity
- Includes original vent pipe in the package
- Equipped with an oxygen-free copper heat exchanger
- Offers four preset modes and a 95°F to 155°F temperature range
- Built-in freeze protection rated down to 14°F
Cons
- Not rated for altitudes above 2,000 feet
- Requires manual water draining below 14°F to prevent freezing damage
- Restricted to indoor installation only
Good fit if
- You live at an elevation under 2,000 feet.
- You need to supply three to four fixtures simultaneously using natural gas.
- You want an indoor unit that includes the matching vent pipe.
Skip if
- You live at an altitude higher than 2,000 feet.
- You need an outdoor-mounted water heater.
Verdict: Ranein 4.3 GPM Indoor Natural Gas Tankless Water Heater pairs 100,000 BTU heating performance with an included vent pipe and flexible temperature presets. It is an efficient choice for low-elevation homes operating multiple taps at once.
APUS 4.42 GPM Natural Gas Tankless Water Heater
Best for: quiet indoor natural gas heating setups
- Fuel Type
- Natural Gas (what this guide is about)
- Flow Rate
- 4.42 GPM
- BTU
- 95,000 BTU
- Installation Location
- Indoor
- Voltage
- 120V AC
- Temperature Control
- ±1°F, 95°F-140°F
View on Amazon: APUS 4.42 GPM Natural Gas Tankless Water Heater
The APUS 4.42 GPM Natural Gas Tankless Water Heater is an indoor unit producing up to 95,000 BTU. It delivers a maximum flow rate of 4.42 GPM and starts heating at a low 0.66 GPM flow. With an operating noise level of 36 dB and dimensions of 20.55 by 13.27 by 5.91 inches, you get steady 95°F to 140°F hot water for small to mid-sized households needing multiple simultaneous taps.
Pros
- 95,000 BTU heating capacity with up to 4.42 GPM flow rate
- Low minimum activation flow rate of 0.66 GPM
- Quiet 36 dB operating noise level
- Copper heat exchanger with 0.81 UEF rating
Cons
- Indoor installation only
- Requires manual draining when ambient temperatures approach 41°F
- Maximum temperature setting is limited to 140°F
Good fit if
- You need up to 4.42 GPM to supply multiple fixtures simultaneously
- You want a quiet indoor unit operating at 36 dB
- You use low-flow fixtures that trigger at 0.66 GPM
Skip if
- You need an outdoor-rated water heater
- You require water temperatures exceeding 140°F
Verdict: APUS 4.42 GPM Natural Gas Tankless Water Heater provides steady 95,000 BTU heating with low 36 dB noise and a 0.66 GPM activation point. It serves indoor installations needing balanced capacity for multiple simultaneous taps.
Rinnai 7.6 GPM Outdoor Natural Gas Water Heater
Best for: Outdoor installation in high-demand homes
- Fuel Type
- Natural Gas (what this guide is about)
- Flow Rate
- 7.6 GPM
- Installation Location
- Outdoor
- Dimensions
- 24.6 x 14.1 x 10.8 in
- Venting Type
- Non-Condensing
- Weight
- 53.3 pounds
View on Amazon: Rinnai 7.6 GPM Outdoor Natural Gas Water Heater
This outdoor non-condensing unit delivers up to 7.6 GPM of continuous hot water, enough to support up to six fixtures at once. Measuring 24.6 by 14.1 by 10.8 inches and weighing 53.3 pounds, it mounts outside to save interior wall space. It suits larger households with high hot water demand that need an exterior-mounted natural gas system.
Pros
- Delivers up to 7.6 GPM to run up to 6 fixtures simultaneously
- Outdoor installation eliminates indoor venting runs
- LED screen shows service reminders and error codes
- Offers up to a 15-year warranty on the heat exchanger
Cons
- Outdoor installation only
- Requires separate purchase of Controlr module for WiFi control
- Does not include an internal recirculation pump
Good fit if
- You need to run up to six fixtures at the same time.
- You prefer an exterior wall installation to preserve indoor utility space.
- You want a high-output natural gas unit with long warranty coverage.
Skip if
- You require an indoor water heater installation.
- You want built-in WiFi connectivity or an integrated pump out of the box.
Verdict: Rinnai 7.6 GPM Outdoor Natural Gas Water Heater provides high-capacity hot water for multiple fixtures from an exterior wall. It works well if you want high output without taking up interior space.
Rheem RTG 9.5 GPM Natural Gas Water Heater
Best for: large homes needing high simultaneous indoor flow
- Fuel Type
- Natural Gas (what this guide is about)
- Flow Rate
- 9.5 GPM
- BTU
- 199,900 BTU/hr
- Installation Location
- Indoor
- Temperature Control
- ±1°F
- Certification
- CSA
The Rheem RTG 9.5 GPM is an indoor natural gas tankless water heater designed for high-demand homes. It delivers up to 199,900 BTU per hour and a 9.5 GPM flow rate at a 35°F rise, supporting three to four simultaneous showers. You get built-in WiFi monitoring, direct venting, and digital controls accurate to 1°F. It suits your multi-bathroom household if you need high capacity without installing an outdoor unit.
Pros
- 199,900 BTU/hr output delivering up to 9.5 GPM at a 35°F rise
- Built-in WiFi connectivity and digital LED display with ±1°F precision
- 15-year heat exchanger and 5-year parts warranty
- Built-in freeze protection and flame failure protection
Cons
- Non-condensing design with a 0.82 Uniform Energy Factor
- Direct vent indoor configuration requires professional installation
Good fit if
- You run three to four hot water fixtures at the same time.
- You want remote WiFi controls and precision ±1°F adjustments.
- You need a high-capacity indoor wall-mount natural gas unit.
Skip if
- You need an outdoor-rated installation.
- You prefer a condensing model with an efficiency factor above 0.82.
Verdict: Rheem RTG 9.5 GPM Indoor Natural Gas Water Heater pairs a high 199,900 BTU output with WiFi controls to supply multiple bathrooms at once. It provides dependable indoor capacity backed by a 15-year heat exchanger warranty.
Thermomate 3.06 GPM Natural Gas Tankless Water Heater
Best for: single-fixture setups and smaller households
- Fuel Type
- Natural Gas (what this guide is about)
- Flow Rate
- Up to 3.06 GPM
- BTU
- 75,000 BTU/hr
- Installation Location
- Indoor
- Temperature Control
- 90–140 °F, ±1°F
- Dimensions
- 21" H x 13" W x 7" D
View on Amazon: Thermomate 3.06 GPM Natural Gas Tankless Water Heater
The Thermomate 3.06 GPM Natural Gas Tankless Water Heater provides on-demand hot water for compact indoor spaces. With a 75,000 BTU heating capacity and a maximum flow rate of 3.06 GPM, it handles a single shower at 2 GPM under 52°F incoming water. It features a 0.81 UEF rating, oxygen-free copper heat exchanger, and 90°F to 140°F digital control, making it practical if you have smaller household hot water demands.
Pros
- Delivers up to 3.06 GPM with a 75,000 BTU natural gas burner
- Energy-efficient operation with a 0.81 UEF rating and oxygen-free copper heat exchanger
- Precise 90°F to 140°F temperature adjustment via a 3.5-inch diagnostic LED display
- Built-in frost protection activates automatically at 41°F
Cons
- Max 3.06 GPM flow rate limits concurrent fixture use
- 75,000 BTU output is not intended for whole-home demand in cold climates
Good fit if
- You need a dedicated indoor water heater for a single shower or small bathroom.
- You want a compact wall-mount unit with standard 1/2-inch gas and 3/4-inch water connections.
Skip if
- You regularly run multiple hot water fixtures at the same time.
- You live in a cold region requiring higher flow rates above 3.06 GPM.
Verdict: Thermomate 3.06 GPM Natural Gas Tankless Water Heater delivers steady temperature stability and dependable performance for point-of-use or modest single-fixture applications.
QERPRE 3.6 GPM Natural Gas Tankless Water Heater
Best for: low-pressure indoor setups below 2,000 feet
- Fuel Type
- Natural Gas (what this guide is about)
- Flow Rate
- 3.6 GPM
- BTU
- 85,000 BTU/hr
- Installation Location
- Indoor
- Temperature Control
- ±1°F
- Dimensions
- 22 x 14 x 6.5 inches
View on Amazon: QERPRE 3.6 GPM Natural Gas Tankless Water Heater
The QERPRE 3.6 GPM Natural Gas Tankless Water Heater delivers 85,000 BTU per hour for indoor setups serving two to three fixtures. You get self-modulating temperature control accurate to 1°F, standard 1/2-inch NPT fittings, and an included exhaust pipe. It activates at water pressures as low as 3.6 PSI. This unit suits smaller households seeking dedicated indoor natural gas water heating without buying separate exhaust piping.
Pros
- Includes exhaust pipe in the box
- Ignites at low water pressure down to 3.6 PSI
- Self-modulating burner stabilizes temperature within ±1°F
- Three operational presets including a bathtub volume alert
Cons
- Not recommended for installations above 2,000 feet altitude
- Capped at 3.6 GPM flow rate and 85,000 BTU output
- Uses 1/2-inch NPT connections rather than 3/4-inch
Good fit if
- You live at an altitude below 2,000 feet.
- You experience low incoming water pressure down to 3.6 PSI.
- You want an indoor heater supplied with an exhaust pipe.
Skip if
- You live at an elevation exceeding 2,000 feet.
- You require flow rates above 3.6 GPM for high concurrent water usage.
Verdict: QERPRE 3.6 GPM Natural Gas Tankless Water Heater delivers steady indoor heating with included exhaust hardware for households situated below 2,000 feet elevation. Its 85,000 BTU output and low-pressure ignition reliably support two to three concurrent fixtures.
APUS 190,000 BTU Outdoor Natural Gas Water Heater
Best for: large households with outdoor space
- Fuel Type
- Natural Gas (what this guide is about)
- Flow Rate
- 8.1 GPM
- BTU
- 190,000 BTU
- Installation Location
- Outdoor
- Voltage
- 120V AC
- Temperature Control
- 95°F–149°F, ±1°F
View on Amazon: APUS 190,000 BTU Outdoor Natural Gas Water Heater
The APUS 190,000 BTU unit delivers 8.1 GPM of hot water for whole-house use. It features outdoor installation and smart temperature control via the Tuya app. The system maintains a stable ±1°F accuracy across a 95°F–149°F range. Its ultra-low 0.79 GPM minimum flow ensures reliable performance even with weak water pressure. This model suits large homes needing high output.
Pros
- 190,000 BTU input provides 8.1 GPM flow rate
- Smart temperature control via Tuya app or wired controller
- Stable ±1°F temperature accuracy
- Ultra-low 0.79 GPM minimum flow requirement
Cons
- Outdoor installation only
- 2-year warranty is shorter than standard industry norms
- Requires 120V AC power connection
Good fit if
- You need high flow for multiple simultaneous fixtures
- You want precise temperature control via a smartphone app
- You have an outdoor location for installation
Skip if
- You require indoor installation only
- You need a warranty longer than 2 years
- You have very low water pressure issues
Verdict: APUS 190k BTU Outdoor Natural Gas Heater is a high-output option for large households with outdoor space. It prioritizes flow rate and smart control over long-term warranty coverage.
MIZUDO 8.1 GPM Outdoor Natural Gas Tankless Heater
Best for: outdoor whole-house hot water
- Fuel Type
- Natural Gas (what this guide is about)
- Flow Rate
- 8.1 GPM
- BTU
- 180,000 BTU
- Installation Location
- Outdoor
- Voltage
- 120V
- Temperature Control
- ±1°F, up to 167°F
View on Amazon: MIZUDO 8.1 GPM Outdoor Natural Gas Tankless Heater
This MIZUDO unit delivers 8.1 GPM at 180,000 BTU for whole-house outdoor use. It features precise ±1°F temperature control and a low 0.53 GPM activation rate. The 26.2 x 17.1 x 7.1 inch design fits exterior walls. You get a 2-year full warranty and 5-year heat exchanger coverage. It suits busy homes needing high flow for multiple bathrooms and laundry.
Pros
- 8.1 GPM flow rate supports 2–3 bathrooms simultaneously
- 180,000 BTU input provides rapid heating in 13 seconds
- ±1°F precise temperature control with adjustable range up to 167°F
- 0.53 GPM low-flow activation for efficiency at faucets and showers
- CSA certified for safe outdoor installation
Cons
- Outdoor installation only, not suitable for indoor use
- Not recommended for elevations above 2,000 feet
- Requires professional installation with 3/4" NPT connections
Good fit if
- You need high flow for a large household with multiple bathrooms
- You have an exterior wall for outdoor installation
- You want precise temperature control for soaking tubs or laundry
Skip if
- You require indoor installation
- You live at an elevation above 2,000 feet
- You prefer a compact unit for small spaces
Verdict: MIZUDO 180,000 BTU Outdoor Natural Gas Heater delivers high capacity for busy outdoor setups. It fits homes needing strong simultaneous flow for multiple fixtures without indoor space constraints.
Rheem RTG 9.5 GPM Outdoor Natural Gas Tankless Heater
Best for: multi-bathroom homes needing outdoor-only installation
- Fuel Type
- Natural Gas (what this guide is about)
- Flow Rate
- 9.5 GPM
- BTU
- 199,900 BTU/hr
- Installation Location
- Outdoor
- Temperature Control
- ±1°F
- Certification
- CSA
View on Amazon: Rheem RTG 9.5 GPM Outdoor Natural Gas Tankless Heater
The Rheem RTG Series delivers up to 9.5 GPM at a 35°F rise using a 199,900 BTU burner. Designed for outdoor wall mounting, it eliminates indoor exhaust venting requirements entirely. It features a 0.82 Uniform Energy Factor and digital temperature control with precision to 1°F. This unit suits you if you run a large household with three to four simultaneous showers and prefer exterior installation.
Pros
- 199,900 BTU output provides up to 9.5 GPM at a 35°F rise
- Outdoor wall mounting eliminates indoor exhaust ducting
- Digital LED control panel adjusts temperature by 1°F increments
- 15-year heat exchanger warranty and 5-year parts warranty
Cons
- Designed exclusively for outdoor installation
- Lower 0.82 UEF efficiency compared to condensing units
- Does not include Wi-Fi connectivity
Good fit if
- You want an exterior setup that avoids running indoor vent pipes.
- You need sufficient flow for three to four simultaneous showers.
- You want precise digital temperature adjustment within 1°F.
Skip if
- You need an indoor-mounted tankless water heater.
- You require built-in Wi-Fi monitoring and controls.
Verdict: Rheem RTG Series 9.5 GPM Outdoor Gas Tankless Heater provides high flow capacity for multi-bathroom homes without taking up interior space or requiring indoor exhaust venting. Its 199,900 BTU output handles heavy hot water demand reliably from outside the home.
Rheem RTGH 6.8 GPM Indoor Natural Gas Tankless Heater
Best for: Large households needing high indoor flow
- Fuel Type
- Natural Gas (what this guide is about)
- 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
This Rheem unit delivers 6.8 GPM at a 35°F rise using 120,000 BTUs of natural gas. It features a 0.93 UEF rating and ±1°F digital temperature control. The indoor design includes direct venting and freeze protection. You get endless hot water for multiple showers. The compact 23.7-inch height fits standard spaces. This model suits large households needing high flow.
Pros
- 6.8 GPM flow rate for whole-house use
- 0.93 Uniform Energy Factor for efficiency
- ±1°F precise digital temperature control
- 120,000 BTU/hr heating power
- Built-in freeze protection
Cons
- Indoor installation only
- No WiFi connectivity on this variant
- Requires professional installation
Good fit if
- You need high flow for 2-3 simultaneous showers
- You want ultra-low NOx emissions compliance
- You prefer indoor direct vent installation
Skip if
- You require outdoor installation
- You need WiFi smart home integration
- You want a compact unit under 20 inches tall
Verdict: Rheem RTGH-68DVLN 6.8 GPM Indoor offers high efficiency and precise control for large families. It fits homes needing strong indoor hot water delivery without smart features.
Garvee Natural Gas 3.17 GPM Indoor Unit
Best for: small indoor spaces needing precise temp control
- Fuel Type
- Natural Gas (what this guide is about)
- Flow Rate
- Up to 3.17 GMP
- Installation Location
- Indoor
- Temperature Control
- ±1°F
- Dimensions
- 5.91 x 13.8 x 13.8 inches
- Weight
- 23.2 pounds
This Garvee unit delivers up to 3.17 GPM of hot water for indoor use. It features precise temperature control within ±1°F and includes a full accessory kit for wall mounting. The compact design measures 13.8 inches wide and weighs 23.2 pounds. It is suitable for smaller households or single-point applications where high flow rates are not required.
Pros
- Flow rate of up to 3.17 GPM
- Temperature accuracy within ±1°F
- Includes complete installation accessory kit
- Compact dimensions of 13.8 x 13.8 x 5.91 inches
Cons
- Lower flow rate compared to many competitors on this list
- Indoor installation only
- Heavier than some lightweight alternatives
Good fit if
- You need a compact unit for a small bathroom or kitchen
- You require precise temperature stability within ±1°F
- You want a complete indoor installation kit included
Skip if
- You need high flow rates for multiple simultaneous showers
- You require outdoor installation capability
- You prefer a lighter unit under 20 pounds
Verdict: Garvee Natural Gas 3.17 GPM Indoor Unit suits small households or single-point applications where space is limited and precise temperature control is prioritized over high volume.
FOGATTI 5.1 GPM Natural Gas Outdoor Heater
Best for: Outdoor medium-flow homes
- Fuel Type
- Natural Gas (what this guide is about)
- Flow Rate
- 5.1 GPM
- BTU
- 120,000 BTU
- Installation Location
- Outdoor
- Voltage
- 120V AC
- Temperature Control
- ±1°F
The FOGATTI outdoor unit delivers 5.1 GPM at 120,000 BTU. It uses a copper heat exchanger and includes a remote control panel. The device maintains temperature within ±1°F. It fits homes with medium flow needs. You get precise water servo technology for consistent heat. The compact design allows for simple installation in outdoor spaces.
Pros
- 5.1 GPM flow rate for multiple outlets
- 120,000 BTU heating capacity
- Includes remote control panel
- ±1°F temperature precision
Cons
- Outdoor installation only
- Limited to altitudes below 2000 feet
- Requires ambient temperature above 5°F or active anti-freeze
Good fit if
- You need an outdoor unit for a medium-sized home
- You want precise temperature control within ±1°F
- You prefer a remote control panel for indoor operation
Skip if
- You require an indoor installation model
- You live at an altitude above 2000 feet
- You need a unit for extreme cold climates without active heating
Verdict: FOGATTI 5.1 GPM Natural Gas Outdoor Heater suits buyers needing reliable outdoor performance with precise temperature control. It is ideal for medium families who value a remote panel and consistent hot water delivery.
Novieex 4.3 GPM Indoor Natural Gas Water Heater
Best for: indoor homes below 2,000 feet elevation
- Fuel Type
- Natural Gas (what this guide is about)
- Flow Rate
- 4.3 GPM
- BTU
- 100,000 BTU
- Installation Location
- Indoor
- Voltage
- 110V-120V AC/60Hz
- Temperature Control
- 95°F to 149°F, ±1°F
View on Amazon: Novieex 4.3 GPM Indoor Natural Gas Water Heater
The Novieex 4.3 GPM Indoor Natural Gas Water Heater supplies 100,000 BTU of heating capacity for indoor setups. You get water delivery between 95°F and 149°F in 1°F increments, controlled via a front LED touchscreen. It runs on standard 110V to 120V electrical power and utilizes 1/2-inch NPT connections. This unit suits you if you need moderate indoor flow rates for simultaneous fixtures at elevations under 2,000 feet.
Pros
- Delivers up to 4.3 GPM output at 100,000 BTU
- Precise temperature settings from 95°F to 149°F in 1°F increments
- Exhaust pipe included with the unit
- Low minimum water pressure requirement of 1.5 psi
Cons
- Recommended only for elevations below 2,000 feet
- Limited to a 1-year manufacturer warranty
- Requires a 110V–120V electrical outlet for operation
Good fit if
- You live at an elevation below 2,000 feet.
- You need up to 4.3 GPM across indoor fixtures.
- You have existing 1/2-inch NPT gas and water lines.
Skip if
- You live at an elevation above 2,000 feet.
- You need an outdoor installation.
- You require flow rates greater than 4.3 GPM.
Verdict: Novieex 4.3 GPM Indoor Natural Gas Water Heater provides precise 100,000 BTU heating for mid-demand homes at lower altitudes. Its included exhaust piping and 1/2-inch NPT connections streamline indoor utility closet and basement setups.
Specifications side by side
| Spec | VEVOR 4.3 Gal Natural Gas Tankless Water Heater | VancEpic 4.8 GPM Natural Gas Tankless Heater | Ranein 4.3 GPM Indoor Natural Gas Tankless Water Heater | APUS 4.42 GPM Natural Gas Tankless Water Heater | Rinnai 7.6 GPM Outdoor Natural Gas Water Heater | Rheem RTG 9.5 GPM Natural Gas Water Heater | Thermomate 3.06 GPM Natural Gas Tankless Water Heater | QERPRE 3.6 GPM Natural Gas Tankless Water Heater | APUS 190,000 BTU Outdoor Natural Gas Water Heater | MIZUDO 8.1 GPM Outdoor Natural Gas Tankless Heater | Rheem RTG 9.5 GPM Outdoor Natural Gas Tankless Heater | Rheem RTGH 6.8 GPM Indoor Natural Gas Tankless Heater | Garvee Natural Gas 3.17 GPM Indoor Unit | FOGATTI 5.1 GPM Natural Gas Outdoor Heater | Novieex 4.3 GPM Indoor Natural Gas Water Heater |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Fuel Type | Gas | Natural Gas | Natural Gas | Natural Gas | Natural Gas | Natural Gas | Natural Gas | Natural Gas | Natural Gas | Natural Gas | Natural Gas | Natural Gas | Natural Gas | Natural Gas | Natural Gas |
| Flow Rate | not specified | 4.8 GPM | 4.3 GPM | 4.42 GPM | 7.6 GPM | 9.5 GPM | Up to 3.06 GPM | 3.6 GPM | 8.1 GPM | 8.1 GPM | 9.5 GPM | 6.8 GPM | Up to 3.17 GMP | 5.1 GPM | 4.3 GPM |
| BTU | 100,000 BTU/hr | 110,000 BTU | 100,000 BTU | 95,000 BTU | not specified | 199,900 BTU/hr | 75,000 BTU/hr | 85,000 BTU/hr | 190,000 BTU | 180,000 BTU | 199,900 BTU/hr | 120,000 BTU/hr | not specified | 120,000 BTU | 100,000 BTU |
| Installation Location | Indoor | Indoor | Indoor | Indoor | Outdoor | Indoor | Indoor | Indoor | Outdoor | Outdoor | Outdoor | Indoor | Indoor | Outdoor | Indoor |
| Capacity | 4.3 Gal | not specified | not specified | not specified | not specified | not specified | not specified | not specified | not specified | not specified | not specified | not specified | not specified | not specified | not specified |
| Voltage | not specified | not specified | not specified | 120V AC | not specified | not specified | not specified | not specified | 120V AC | 120V | not specified | not specified | not specified | 120V AC | 110V-120V AC/60Hz |
| Temperature Control | ±1°F | ±1°F | 95°F-155°F | ±1°F, 95°F-140°F | not specified | ±1°F | 90–140 °F, ±1°F | ±1°F | 95°F–149°F, ±1°F | ±1°F, up to 167°F | ±1°F | ±1°F | ±1°F | ±1°F | 95°F to 149°F, ±1°F |
| Certification | not specified | not specified | not specified | not specified | not specified | CSA | not specified | not specified | not specified | CSA | CSA | CSA | not specified | CSA | not specified |
| Dimensions | 21.7 x 13.8 x 13.8 inches | 24.6 x 14.4 x 14.4 in | 25.6 x 16.9 x 16.9 inches | 20.55 x 13.27 x 5.91 inches | 24.6 x 14.1 x 10.8 in | 24.2 x 13.5 x 10.3 inches | 21" H x 13" W x 7" D | 22 x 14 x 6.5 inches | 22.48 x 15.51 x 6.54 in | 26.2 x 17.1 x 7.1 inches | 20.8 x 13.5 x 9.4 inches | 23.7 x 17.7 x 9.8 inches | 5.91 x 13.8 x 13.8 inches | 26.2 x 17.1 x 7.1 inches | 28.5 x 17.3 x 10.8 in |
| Use | Whole House | not specified | not specified | not specified | not specified | not specified | not specified | Whole House | not specified | not specified | not specified | not specified | not specified | not specified | not specified |
| Venting Type | not specified | Non-Condensing | not specified | not specified | Non-Condensing | Non-Condensing | not specified | not specified | not specified | not specified | Non-Condensing | not specified | not specified | not specified | not specified |
| Features | not specified | not specified | not specified | not specified | not specified | WiFi | not specified | not specified | not specified | not specified | WiFi | WiFi | not specified | not specified | not specified |
| Weight | 19.8 pounds | 25.4 pounds | not specified | 19.2 pounds | 53.3 pounds | 46.5 pounds | 19.8 pounds | 24.1 pounds | 42.5 pounds | not specified | 39.3 pounds | 59.9 pounds | 23.2 pounds | 29.3 pounds | 19.8 pounds |
| Size | 4.3 Gal | 4.8GPM, 110,000BTU, NG | 4.3 GPM Indoor | not specified | 9.8 GPM | 9.5 GPM (WiFi) | not specified | 3.6GPM,Natural Gas | not specified | Natural Gas, 8.1 GPM, 180,000 BTU, Indoor | 9.5 GPM (No WiFi) | 6.8 GPM (No WiFi) | 3.17 GMP | 5.1 GPM, Outdoor Installation | 4.3GPM Nature gas |
| Color | Silver Gray | Non-Condensing | Gray-NG | Natural Gas,4.42GPM,95,000BTU，Space Gray | Silver | Gray | Metallic Silver | Gray | Gray | White 8.1NG | Gray | Gray | White | Gray | Pearl Grey |
| Model | JSQ30-A | VH11K-W-NG-U01 | RH10K | AP-AWH-Q13NG | REU-VE2737WD-US-N | RTG-95DVELN-3 | CZ264NG | 3.6GPM,Natural Gas | AP-AWH-W26NG | HS180A0W-NG | RTG-95XLN-3 | RTGH-68DVLN-3 | PTH_33KVHBTYAg-T | InstaGas Comfort | RS-16 |
Is Natural Gas Worth It?
Natural gas delivers high burner capacity, often reaching 199,900 BTU, to support simultaneous multi-fixture use. You get consistent hot water for whole-house needs without waiting for storage tanks to reheat. The fuel type allows for compact indoor or outdoor mounting. You benefit from precise temperature regulation, often within ±1°F, ensuring steady comfort. However, you must have a gas line and proper venting for indoor units. This setup suits homes with existing natural gas infrastructure.
Worth it if
- You have existing natural gas lines
- You need high simultaneous flow for multiple bathrooms
- You want precise temperature stability
Skip it if
- You lack natural gas infrastructure
- You cannot install required indoor exhaust venting
- You prefer electric-only systems
If you plan to extend your gas line outdoors, you can compare the best natural gas grills by burner output.
How we picked natural gas units
We selected these models by scanning Amazon listings for the Natural Gas fuel type. We looked for products that explicitly list this fuel source in their title or feature descriptions. This ensures every unit on the list runs on natural gas without requiring propane adapters or electric ignition for fuel combustion. We only include one size or variant per product family to keep the comparison clear and direct.
The products are ordered by availability first. Next, we use the listing's overall rating weighted by the number of ratings. Finally, we sort by how many of our core criteria the published specs meet. We rely strictly on the specifications provided by the manufacturer. We do not test these units ourselves, nor do we quote customer opinions or prices.
How to choose the right one
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Match flow to fixtures
Check your simultaneous fixture count. The Rinnai 7.6 GPM Outdoor Natural Gas Water Heater supports high-demand homes with multiple bathrooms. Smaller units like the Thermomate 3.06 GPM suit single-fixture setups. Match the GPM rating to your peak usage. Higher flow rates ensure consistent pressure when multiple taps run. Verify the spec sheet lists the maximum GPM output. This number dictates how many showers or sinks can operate at once without temperature drops.
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Verify installation location
Indoor units require specific venting and clearance. The VEVOR 4.3 Gal Natural Gas Tankless Water Heater is designed for indoor whole-house setups. Outdoor models like the Rinnai 5.3 GPM Outdoor Natural Gas Tankless Heater mount on exterior walls. Choose based on available space and local codes. Indoor units save exterior space but need proper exhaust routing. Outdoor units are weather-resistant but may require insulation in cold climates. Confirm the product attributes list your preferred installation location before purchasing.
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Check burner capacity
BTU output determines heating speed and volume. The Rheem RTG 9.5 GPM Indoor Natural Gas Water Heater offers 199,900 BTU for large homes. Mid-range units like the VancEpic 4.8 GPM provide 110,000 BTU for standard households. Higher BTU values handle colder inlet water temperatures better. Match the BTU rating to your home size and climate. Larger homes with multiple bathrooms benefit from higher capacity. Smaller units may struggle to maintain temperature during heavy use.
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Consider elevation limits
Altitude affects combustion efficiency and output. The Ranein 4.3 GPM Indoor Natural Gas Tankless Water Heater is optimized for setups below 2,000 feet elevation. Higher altitudes may require derating or specific models. Check the specifications for elevation restrictions. Units not rated for your altitude may underperform. If you live above 2,000 feet, look for models with altitude adjustment capabilities. This ensures consistent hot water delivery regardless of air density changes.
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Review temperature control
Precision regulation ensures comfort and safety. The VEVOR 4.3 Gal unit provides tight ±1°F temperature regulation. Look for models with digital displays and precise controls. Consistent temperature prevents scalding and ensures comfort. Units with ±1°F regulation maintain stable output during flow changes. Avoid models with wide temperature swings. Check the specs for temperature stability claims. This feature is crucial for whole-house setups where multiple fixtures draw water simultaneously.
Frequently asked questions
Can I install a natural gas tankless water heater outdoors?
Yes, several models are designed for exterior mounting. The Rinnai 7.6 GPM Outdoor Natural Gas Water Heater and the Rheem RTG 9.5 GPM Outdoor unit both feature outdoor configurations. These units save interior space and do not require indoor exhaust venting. They are suitable for homes needing high output without taking up interior room.
What flow rate do I need for a whole house?
You generally need 4 to 9.5 GPM depending on your fixture count. The VEVOR 4.3 Gal model provides 4.3 GPM for moderate whole-house use. For larger homes with multiple bathrooms, the Rheem RTG 9.5 GPM model offers 9.5 GPM. This higher capacity supports simultaneous use across several fixtures reliably.
How much space does a natural gas tankless heater take?
These units are compact and wall-mountable. The APUS 4.42 GPM model measures just 5.9 inches wide and 20.6 inches tall. The Rinnai 5.3 GPM Outdoor unit is wider at 18 inches but remains slim. Most indoor models fit easily into utility closets or basements without crowding the area.
Do I need special venting for indoor models?
Yes, indoor units typically require dedicated exhaust venting. The Ranein 4.3 GPM model comes with an included vent pipe for easy setup. The VEVOR 4.3 Gal model uses standard 1/2-inch NPT connections. Always verify your local codes for proper venting requirements before installation to ensure safe operation.
Which unit is best for low water pressure?
Some models activate at lower flow rates. The APUS 4.42 GPM unit has a low 0.66 GPM activation point. The VELPAX 4.74 GPM model also features low-pressure activation for balanced delivery. These units are suitable for homes with lower incoming water pressure, ensuring reliable ignition and heating even at minimal flow.
Are there smart controls for natural gas heaters?
Yes, select models include WiFi or app connectivity. The Rheem RTG 9.5 GPM Indoor model features WiFi controls for remote management. The APUS 6.8 GPM unit pairs with the Tuya app for whole-home control. These features allow you to monitor and adjust settings from your smartphone conveniently.
Can I use these units at high elevations?
Many models are optimized for low elevations below 2,000 feet. The Ranein 4.3 GPM and Novieex 4.3 GPM units are specified for indoor setups below this altitude. The Amzgachfktch 4.75 GPM model also targets low-elevation homes. Check the specifications carefully if you live at higher altitudes to ensure proper performance.