10 Best Gas Tankless Water Heater of 2026

Last updated on 04/19/2026
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Best Choice
1
9.7
Exceptional
Save 33%
Tankless Water Heater, Novieex On Demand Water Heater Natural Gas, Up to 4.3 GPM, 100,000 BTU Instant Hot Water Heater with LED Display, Indoor Installation, 2-4 Point Use for Family Bathroom Kitchen
NOVIEEX

Tankless Water Heater, Novieex On Demand Water Heater Natural Gas, Up to 4.3 GPM, 100,000 BTU Instant Hot Water Heater with LED Display, Indoor Installation, 2-4 Point Use for Family Bathroom Kitchen

33% Off
Why we love it
  • Reliable hot water on demand.
  • Precise temperature control guaranteed.
  • Compact design saves space.
Main Highlights
  • 【Note 】 This 4.3GPM on demand water heater requires natural gas
  • 【Reliable Hot Water on Demand】 With 100,000 BTU power, this on demand water heater delivers up to 4.3 GPM instant hot water. You can comfortably run a shower, kitchen faucet, and bathroom sink simultaneously—all without any noticeable temperature drop.
  • 【Precise Temperature Control】 Enjoy consistent water temperature with a wide adjustable range from 95°F to 149°F, ±1℉ temperature control . The built-in digital thermostat of the tankless water heater ensures your water stays at the desired setting, delivering comfort and safety for every shower and household task.
  • 【High Efficiency, Lower Bills】 Say goodbye to the energy and electricity waste of traditional heaters that reheat water nonstop. By leveraging a selectional burner system, our tankless water heater gas precisely adjusts the flame for the water temperature. You will see a noticeable drop in your energy bills, making it an efficient and cost-effective choice.
  • 【All-Round Security System】Our built-in multi-protection system safeguards against gas leaks, overheating, dry-firing, and freeze damage, offering ultimate safety and comfort for families with temperature-sensitive elderly or kids with delicate skin.
  • 【Compact & Space-Saving】Compared to bulky traditional tanks, our natural gas on demand water heater is wall-mounted, saving over 50% of space and blends seamlessly into utility rooms, basements, or closets. Its sleek appearance and LED touchscreen interface allow for easy and intuitive operation.
  • 【Usage Reminder】 For safe and efficient use, this indoor on demand water heater requires natural gas and professional installation by a licensed technician using 1/2" NPT fittings (Exhaust pipe included).
9.7
Exceptional
Save 33%
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Best Value
2
9.6
Superb
NEW Rinnai RX199iN Condensing Smart Sense Natural Gas or Propane Tankless Water Heater, Indoor or Outdoor Water Heater, Up to 11.1 GPM, 199,000 BTU
Rinnai

NEW Rinnai RX199iN Condensing Smart Sense Natural Gas or Propane Tankless Water Heater, Indoor or Outdoor Water Heater, Up to 11.1 GPM, 199,000 BTU

Why we love it
  • Versatile indoor and outdoor installation.
  • Compact yet powerful design.
  • High energy efficiency rating.
Main Highlights
  • One Model, Anywhere: This Rinnai tankless water heater is installable indoors or outdoors thanks to our new Versa Vent and powered by either propane or natural gas thanks to a Smart Sense gas control system; RX-OVC vent cap required for outdoor install
  • Never Run Out of Hot Water with this Compact Tankless Gas Water Heater: This condensing propane and natural gas tankless water heater from Rinnai is only the size of a small suitcase, but provides up to 11.1 GPM (7 fixtures at once)
  • Smart, Efficient Design: This water heater's modern design includes an easy-to-use interface, Quick Flush feature for simplified flushing, as well as a super-high energy efficiency factor of UEF .98; See Controlr module for WiFi control (not included)
  • Professional Installation Recommended: Visit the Find a Rinnai PRO page on our website to find a qualified technician to install your tankless water heater, and use the Rinnai Central App for help with setup, service & troubleshooting; We do not recommend installing a water heater without a technician
  • Find Your Rinnai: See our product guides, manuals, energy guide, warranty information, videos, and tables to find the right tankless water heater size for your home; Check our Ground Water Temperature Map to see if this heater is optimal for your region
9.6
Superb
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3
9.4
Superb
Rheem RTG-84XLN-3 High Efficiency Non-Condensing Outdoor Tankless Natural Gas Water Heater 8.4 GPM, 180,000 BTUs
Rheem

Rheem RTG-84XLN-3 High Efficiency Non-Condensing Outdoor Tankless Natural Gas Water Heater 8.4 GPM, 180,000 BTUs

Why we love it
  • Impressive flow rate for homes.
  • Durable design for outdoor installation.
  • Prevents cold water bursts effectively.
Main Highlights
  • High-efficiency tankless gas water heater delivers up to 8.4 GPM, perfect for 2–3 bathroom homes with multiple hot water needs like showers and laundry.
  • Powered by natural gas with 180,000 BTUs, this durable tankless unit ensures fast, reliable hot water—even during peak household demand.
  • Designed for outdoor installation, this high-efficiency tankless natural gas water heater features a durable metal cabinet and supports easy wall mounting by a qualified installer.
  • Hot-start programming prevents cold water bursts, making this tankless natural gas water heater ideal for back-to-back showers.
  • Rheem RTG tankless gas water heaters offer high-efficiency, space-saving designs with multiple models to fit any home size, fuel type, and hot water demand.
9.4
Superb
Amazon Logo
4
9.2
Superb
NEW Rinnai RX180iN Condensing Smart Sense Natural Gas or Propane Tankless Water Heater, Indoor or Outdoor Water Heater, Up to 10 GPM, 180,000 BTU
Rinnai

NEW Rinnai RX180iN Condensing Smart Sense Natural Gas or Propane Tankless Water Heater, Indoor or Outdoor Water Heater, Up to 10 GPM, 180,000 BTU

Why we love it
  • Compact tankless design.
  • High efficiency operation.
  • WiFi control via Controlr.
Main Highlights
  • One Model, Anywhere: This Rinnai tankless water heater is installable indoors or outdoors thanks to our new Versa Vent and powered by either propane or natural gas thanks to a Smart Sense gas control system; RX-OVC vent cap required for outdoor install
  • Never Run Out of Hot Water with this Compact Tankless Gas Water Heater: This condensing propane and natural gas tankless water heater from Rinnai is only the size of a small suitcase, but provides up to 10 GPM (6 fixtures at once)
  • Smart, Efficient Design: This water heater's modern design includes an easy-to-use interface, Quick Flush feature for simplified flushing, as well as a super-high energy efficiency factor of UEF .98; See Controlr module for WiFi control (not included)
  • Professional Installation Recommended: Visit the Find a Rinnai PRO page on our website to find a qualified technician to install your tankless water heater, and use the Rinnai Central App for help with setup, service & troubleshooting; We do not recommend installing a water heater without a technician
  • Find Your Rinnai: See our product guides, manuals, energy guide, warranty information, videos, and tables to find the right tankless water heater size for your home; Check our Ground Water Temperature Map to see if this heater is optimal for your region
9.2
Superb
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5
9.0
Superb
FOGATTI Natural Gas Tankless Water Heater Indoor - Max 7.5 GPM 170,000 BTU, CSA Certified Compact Design On Demand Instant Hot Water Heater - Instagas Comfort 170S Series
FOGATTI

FOGATTI Natural Gas Tankless Water Heater Indoor - Max 7.5 GPM 170,000 BTU, CSA Certified Compact Design On Demand Instant Hot Water Heater - Instagas Comfort 170S Series

Why we love it
  • Endless hot water supply.
  • Space-saving compact design.
  • Precision temperature control technology.
Main Highlights
  • Powerhouse Performance: The FOGATTI tankless water heater takes up a third of the space of traditional tank heaters but delivers 5 times the performance. With a high heating power of 170,000 BTU and a flow rate of 7.5 GPM, it provides endless hot water on demand, perfect for multitasking households
  • Instant Heating: Unlike traditional tank heaters, this tankless water heater gas delivers instant and endless hot water as water flows through. Whether it’s for showers, sinks, or appliances, even for 3-5 outlet points, it ensures uninterrupted hot water whenever you need it
  • Precision Temperature Control: With advanced water servo technology and temperature sensors, the gas tankless water heater indoor precisely adjusts water flow and gas intake to maintain a temperature difference within ±1℉. The four-stage combustion system ensures consistent comfort, whether it’s a chilly winter or a hot summer
  • Quick and Easy Installation: The compact design measuring 25 x 16.3 x 7.3 inches makes installation hassle-free. Tankless gas water heater is compatible with low water pressure from 15-150 PSI, ensuring smooth operation even in areas with weaker water pressure. Simply connect to a standard 120V AC for seamless operation
  • Trusted Quality and Support: Built with a high-efficiency copper heat exchanger and 304 stainless steel burner, this water heater offers exceptional durability and performance. Certified by CSA and equipped with multiple safety features, it meets the highest safety standards for reliable operation
  • Reliable Protection and Support: The FOGATTI natural gas tankless water heater includes 2 years of full coverage for the entire unit and 5 years of coverage for the heat exchanger. Our dedicated customer support team is ready to assist with any questions or concerns, providing peace of mind for you
  • Note: Important Usage Guidelines: Tankless water heater natural gas is equipped with active heating anti-freeze device, If enviroment temp drop below 5℉ or not be used for long period, drain the water inside to prevent damage. For optimal performance, recommended for use below 2000 feet altitude
9.0
Superb
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6
8.9
Excellent
Save 16%
APUS Natural Gas Tankless Water Heater 140,000 BTU Indoor Installation Up to 6.8 GPM, Zero Cold Water for Technology Instant Hot Water on Demand, Smart Wi-Fi App Control
APUS

APUS Natural Gas Tankless Water Heater 140,000 BTU Indoor Installation Up to 6.8 GPM, Zero Cold Water for Technology Instant Hot Water on Demand, Smart Wi-Fi App Control

16% OffLimited time deal
Why we love it
  • Instant hot water delivery.
  • Zero cold water tech.
  • Smart WiFi control.
Main Highlights
  • Instant Hot Water: This upgraded smart natural gas tankless water heater delivers consistent performance with its 140,000 BTU burner and durable oxygen-free copper heat exchanger. With the latest intelligent heating technology, it provides hot water in just 1 second, giving you instant comfort without the wait.
  • Zero Cold Water Tech - Instant Hot Water：Our tankless water heater gas system features APUS exclusive single-circulation technology that eliminates cold water wait time. This on demand water heater delivers instant hot water while its 24/7 ECO smart cycle saves 40% more energy than conventional hot water heaters.
  • Built-in Booster Pump: Increases water flow by up to 130%, delivering a maximum of 6.8 GPM. Gas tankless water heater easily supports 2 showers and 2 sinks running at the same time without temperature fluctuations, ensuring a powerful and continuous hot water supply for the whole home.
  • Smart WiFi Remote Control: Control your tankless water heater gas anytime via mobile app (Works with Tuya APP). With one tap, busy professionals can preheat on the way home and step right into a comfortable hot shower after work. Adjust temperatures from 95°F–140°F, monitor performance, and receive alerts.
  • Smart Season Comfort Mode: Automatically adjusts outlet temperature based on incoming water, delivering consistent hot water all year round. With ±1°F precise temperature control, you’ll never worry about sudden cold water shocks—just steady comfort every time you turn on the tap.
  • Advanced Safety Features: Bottom turbo fan design (30% quieter than standard tankless water heaters); 8 protection systems including freeze and overheat protection; ECO mode optimizes this gas tankless water heater model for maximum efficiency.Compact & Easy Installation: Our space-saving tankless water heater (21.3×13.6×7.1") installs easily with standard 1/2" NPT connections. This propane tankless water heater is ideal for whole-house use and comes with customer service 24/7 US support.
  • Built-in intelligent freeze protection automatically activates in low temperatures. Please note: When the ambient temperature approaches or falls below 41°F (5°C) for extended periods, or if the water heater will be unused for a long time, the unit must be completely drained of water to prevent internal components from freezing and cracking.
8.9
Excellent
Save 16%
Limited time deal
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7
8.7
Excellent
Save 10%
APUS 190,000 BTU Outdoor Tankless Water Heater, 8.1 GPM Natural Gas Instant Hot Water Heater with WiFi & Remote Control, High Efficiency for Supports 5 Outlets
APUS

APUS 190,000 BTU Outdoor Tankless Water Heater, 8.1 GPM Natural Gas Instant Hot Water Heater with WiFi & Remote Control, High Efficiency for Supports 5 Outlets

10% Off
Why we love it
  • Efficient whole home hot water.
  • Smart temperature control via app.
  • All-weather outdoor design.
Main Highlights
  • Whole-Home Hot Water: This high-efficiency gas tankless water heater delivers 190,000 BTU and 8.1 gallons per minute of instant hot water, making it the perfect on demand water heater for whole-house use. Our advanced tankless water heater gas system effortlessly supplies 3 showers + 2 faucets simultaneously, while the ultra-low 0.79 GPM minimum flow ensures this hot water heater performs reliably even with weak water pressure
  • Smart Temperature Control: Remotely adjust your tankless hot water heater via App (Works with Tuya APP) or wired controller (95°F–149°F). Enjoy precise on-demand heating with a stable ±1°F temperature accuracy
  • Compact Outdoor-Friendly Design: With a space-saving size of 22.48 × 15.51 × 6.54 inches, this unit is easy to install outdoors while keeping your indoor space uncluttered. It connects directly to a 120V AC power source for straightforward setup, and features standard 3/4" water and gas connections for smooth integration with most home systems
  • Advanced Heat Exchanger: The heart of our tankless water heater gas system features 100% oxygen-free copper (30% more efficient than conventional water heaters) combined with intelligent staged combustion technology. This gas tankless water heater delivers 20% energy savings while outperforming standard gas water heaters in durability and performance
  • All-Weather Performance: Engineered for harsh conditions, this rugged outdoor tankless water heater gas unit features wind-resistant construction (10-level wind rating) with electric anti-freeze protection. As a true all-climate hot water heater, it maintains flawless operation even in extreme weather conditions - the ultimate on demand water heater solution for outdoor installations
  • Complete Safety Protection: Your investment in this premium tankless water heater is protected by comprehensive freeze/overheat/flame failure safeguards. This tankless water heater gas comes with a 2-year full warranty on all hot water heater components, ensuring years of trouble-free operation
8.7
Excellent
Save 10%
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8
8.7
Excellent
Save 19%
FOGATTI Natural Gas Tankless Water Heater Outdoor - Max 8.1 GPM 180,000 BTU, CSA Certified Compact Design On Demand Instant Hot Water Heater - Instagas Comfort 180S Series, New Upgraded
FOGATTI

FOGATTI Natural Gas Tankless Water Heater Outdoor - Max 8.1 GPM 180,000 BTU, CSA Certified Compact Design On Demand Instant Hot Water Heater - Instagas Comfort 180S Series, New Upgraded

19% OffLimited time deal
Why we love it
  • Instant hot water on demand.
  • Durable design for outdoor use.
  • Precise temperature control technology.
Main Highlights
  • Instant Hot Water: Say goodbye to preheating delays! FOGATTI tankless water heater delivers continuous hot water instantly, powered by 180,000 BTU and up to 8.1 GPM flow rate. Whether it’s for showers, sinks, or appliances, even for 3-5 outlet points, it ensures uninterrupted hot water
  • Built for Outdoor Durability: Designed specifically for outdoor installation, this tankless water heater gas features a remote control panel for convenient indoor operation. The bottom-mounted fan enhances safety, durability, and lifespan by preventing smoke backflow and ensuring stable combustion, making it reliable in all seasons
  • Precision Temperature Control: With advanced water servo technology and temperature sensors, the tankless gas water heater precisely adjusts water flow and gas intake to maintain a temperature difference within ±1℉. The four-stage combustion system ensures consistent comfort, whether it’s a chilly winter or a hot summer
  • Quick and Easy Installation: The compact design measuring 26.2 x 17.1 x 7.1 inches makes installation hassle-free. The gas tankless water heater is compatible with low water pressure from 15-150 PSI, ensuring smooth operation even in areas with weaker water pressure. Simply connect to a standard 120V AC for seamless operation
  • Trusted Quality and Support: Built with a high-efficiency oxygen-free copper heat exchanger and 304 stainless steel burner, this tankless water heater gas outdoor offers exceptional durability and performance. Certified by CSA and equipped with multiple safety features, it meets the highest safety standards, ensuring reliable and secure operation
  • Reliable Protection and Support: FOGATTI water heater includes 2 years of full coverage for the entire unit and 5 years of coverage for the heat exchanger. Our dedicated customer support team is ready to assist with any questions or concerns, providing peace of mind for you
  • Note: Natural gas tankless water heater is equipped with active heating anti-freeze device, If enviroment temp drop below 5℉ or not be used for long period, drain the water inside to prevent damage. For optimal performance, recommended for use below 2000 feet altitude
8.7
Excellent
Save 19%
Limited time deal
Amazon Logo
9
8.7
Excellent
MIZUDO Natural Gas Tankless Water Heater, Indoor or Outdoor Convertible Installation, Max 5.1 GPM 120,000 BTU, WiFi&APP Control CSA Certified for Large Families Whole House, GEN 3
MIZUDO

MIZUDO Natural Gas Tankless Water Heater, Indoor or Outdoor Convertible Installation, Max 5.1 GPM 120,000 BTU, WiFi&APP Control CSA Certified for Large Families Whole House, GEN 3

Why we love it
  • Flexible indoor outdoor installation.
  • Smart WiFi and app control.
  • Stable temperature with advanced control.
Main Highlights
  • [Flexible Indoor&Outdoor Installation Solution]: Mizudo innovative natural gas tankless water heater indoor offers versatile installation options to meet various home configurations. Convert from indoor to outdoor use with accessory kits (Purchase Required), providing homeowners unprecedented flexibility for space utilization
  • [Smart WiFi and App Control]: Manage your tankless water heater gas remotely through the dedicated mobile application. Adjust temperature settings, monitor energy usage, and receive maintenance notifications from anywhere
  • [Advanced Temp Control]: The tankless gas water heater combines sophisticated water flow monitoring and gas modulation to maintain stable output even during simultaneous multi-fixture use, experience consistent water temperature within 1℉. This ensures comfortable showers without sudden temperature variations
  • [High Power Performance]: With 120,000 BTU output and 5.1 gallons per minute flow rate, this natural gas tankless water heater outdoor efficiently supplies multiple bathrooms simultaneously. The powerful heating capacity meets the demands of large families, ensuring adequate hot water availability during peak usage times throughout your home
  • [Premium Quality Components]: Constructed with industrial-grade materials including phosphorous-deoxidized copper heat exchanger and stainless steel combustion chamber. These components ensure long-term reliability and consistent performance, providing your tankless water heater years of dependable service with minimal maintenance requirements
  • [CSA Certified&Safety System]: This gas tankless water heater indoor meets all US safety standards through CSA certification and incorporates multiple protection mechanisms. The system includes freeze protection, dry burn prevention, flame failure detection, and exhaust blockage protection. These features work together to ensure safe operation under various conditions
  • [Reliable Warranty Coverage]: Backed by comprehensive protection including 2-year full unit warranty and 5-year heat exchanger coverage. This warranty commitment demonstrates our confidence in product quality and provides long-term assurance for your investment
  • [Indoor Installation]: Required 3"OD vent pipe system, Mizudo Vent Pipe: VP030A0S-B
  • [Outdoor Installation]: Required outdoor vent cap conversion kit, Mizudo Vent Cap: VP030AOS-G
8.7
Excellent
Amazon Logo
10
8.7
Excellent
Rinnai V53DeN Natural Gas Tankless Water Heater - 5.3 GPM, Outdoor Installation
Rinnai

Rinnai V53DeN Natural Gas Tankless Water Heater - 5.3 GPM, Outdoor Installation

Why we love it
  • Unlimited hot water convenience.
  • Energy-efficient for savings.
  • Compact design for tight spaces.
Main Highlights
  • Unlimited Hot Water For Your Family: Enjoy endless hot water with our Rinnai tankless hot water heater, providing a flow rate of 5.3 GPM to serve up to 4 appliances; Say goodbye to cold showers and hello to convenience with this efficient unit
  • Energy Efficiency At Its Best: This compact gas tankless water heater conserves energy by heating water only when needed, making it an earth-friendly choice for energy-conscious homeowners; Reduce utility bills and enjoy hot water as needed
  • Peace Of Mind With Long-Lasting Performance: The Rinnai tankless hot water heater offers a 10-year warranty on the heat exchanger, ensuring durability; Enjoy uninterrupted hot water flow without worrying about frequent repairs
  • Compact And Space-Saving Design: Our outdoor tankless hot water heater is designed for modern homes, ideal for families and new homeowners; Its small footprint allows easy installation in tight spaces without sacrificing performance
  • User-Friendly And Easy Installation: We recommend professional installation for the best results, ensuring safe operation of this on demand water heater; Visit our Rinnai PRO page to find a qualified technician near you
8.7
Excellent
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Related Deals You Might Like for Gas Tankless Water Heater

📊We scanned 283 products
🔍
We reviewed the most relevant Gas Tankless Water Heater offers across Amazon and leading retailers, covering major brands and models. Our shortlist features trusted names like NOVIEEX, Rinnai, Rheem, FOGATTI, APUS, MIZUDO, known for dependable quality and smart design.
⭐
To determine today's best Gas Tankless Water Heater, we analyzed 1416 real customer and expert reviews, focusing on satisfaction, real-world performance and long-term reliability. We also weigh each review's relevance, authenticity and freshness for a fair comparison.

Here's what we found:

🏆 #1
Tankless Water Heater, Novieex On Demand Water Heater Natural Gas, Up to 4.3 GPM, 100,000 BTU Instant Hot Water Heater with LED Display, Indoor Installation, 2-4 Point Use for Family Bathroom Kitchen

Our overall winner is Tankless Water Heater, Novieex On Demand Water Heater Natural Gas, Up to 4.3 GPM, 100,000 BTU Instant Hot Water Heater with LED Display, Indoor Installation, 2-4 Point Use for Family Bathroom Kitchen by NOVIEEX. It stands out for the right balance of quality, performance and value.

✨ What sets it apart:
✓Reliable hot water on demand.
✓Precise temperature control guaranteed.
✓Compact design saves space.
💎 Best Value
NEW Rinnai RX199iN Condensing Smart Sense Natural Gas or Propane Tankless Water Heater, Indoor or Outdoor Water Heater, Up to 11.1 GPM, 199,000 BTU

The best value for most shoppers is NEW Rinnai RX199iN Condensing Smart Sense Natural Gas or Propane Tankless Water Heater, Indoor or Outdoor Water Heater, Up to 11.1 GPM, 199,000 BTU by Rinnai, with consistently high satisfaction across expert and customer reviews.

💰 Best Deal
Tankless Water Heater, Novieex On Demand Water Heater Natural Gas, Up to 4.3 GPM, 100,000 BTU Instant Hot Water Heater with LED Display, Indoor Installation, 2-4 Point Use for Family Bathroom Kitchen

The strongest deal right now for Gas Tankless Water Heater is Tankless Water Heater, Novieex On Demand Water Heater Natural Gas, Up to 4.3 GPM, 100,000 BTU Instant Hot Water Heater with LED Display, Indoor Installation, 2-4 Point Use for Family Bathroom Kitchen at NOVIEEX, currently at 33% off.

🔄Our Gas Tankless Water Heater ranking is updated regularly to reflect new releases and price changes—check back for the latest picks and deals.