10 Best Tankless Gas Water Heaters of 2026

Last updated on 04/04/2026
Advertising disclosure
Best Choice
1
9.8
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).
9.8
Exceptional
Save 33%
Amazon Logo
🛡️Trusted by 100M+ UsersWhy?
Best Value
2
9.8
Exceptional
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
9.8
Exceptional
Amazon Logo
3
9.7
Exceptional
Save 7%
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

7% Off
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
9.7
Exceptional
Save 7%
Amazon Logo
4
9.6
Superb
Rheem RRTGH84DVLN3701171 Rheem RTGH Series 8.4 GPM 157,000 BTU 120 Volt Residential Indoor Natural Gas Tankless Water Heater Stainless Steel
Rheem

Rheem RRTGH84DVLN3701171 Rheem RTGH Series 8.4 GPM 157,000 BTU 120 Volt Residential Indoor Natural Gas Tankless Water Heater Stainless Steel

Why we love it
  • Versatile flow rate options available.
  • Customizable temperature settings provided.
  • Comprehensive warranty for peace of mind.
Main Highlights
  • Flow rate of 0.4 - 8.4 GPM
  • Available temperature settings range from 100 to 140F (default setting of 120F)
  • Includes electric ignition
  • Covered under 1 year labor, 15 year heat exchanger, and 5 year parts manufacturer warranties
  • Width 17-11/16-in
9.6
Superb
Amazon Logo
5
9.4
Superb
Rheem RTG-70DVLN-3 High Efficiency Non-Condensing Indoor Tankless Natural Gas Water Heater 7.0 GPM, 160,000 BTUs
Rheem

Rheem RTG-70DVLN-3 High Efficiency Non-Condensing Indoor Tankless Natural Gas Water Heater 7.0 GPM, 160,000 BTUs

Why we love it
  • Endless hot water supply.
  • Energy-efficient and cost-effective.
  • Protects from water damage.
Main Highlights
  • High-efficiency tankless gas water heater delivers up to 7.0 GPM, perfect for 2–3 bathroom homes with multiple hot water needs like showers and laundry.
  • Powered by natural gas with 160,000 BTUs, this durable tankless unit ensures fast, reliable hot water—even during peak household demand.
  • Designed for indoor installation, this high-efficiency tankless natural gas water heater features a durable, compact 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
6
9.3
Superb
Save 16%
Rheem RTG-95DVLN-3 High Efficiency Non-Condensing Indoor Tankless Natural Gas Water Heater 9.5 GPM, 199,900 BTUs
Rheem

Rheem RTG-95DVLN-3 High Efficiency Non-Condensing Indoor Tankless Natural Gas Water Heater 9.5 GPM, 199,900 BTUs

16% Off
Why we love it
  • Provides endless hot water.
  • Saves energy and reduces costs.
  • Prevents water damage effectively.
Main Highlights
  • High-efficiency tankless gas water heater delivers up to 9.5 GPM, perfect for 2–3 bathroom homes with multiple hot water needs like showers and laundry.
  • Powered by natural gas with 199,900 BTUs, this durable tankless unit ensures fast, reliable hot water—even during peak household demand.
  • Designed for indoor installation, this high-efficiency tankless natural gas water heater features a durable, compact 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.
9.3
Superb
Save 16%
Amazon Logo
7
9.3
Superb
Save 9%
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

9% Off
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.
9.3
Superb
Save 9%
Amazon Logo
8
9.1
Superb
Rinnai RE199iN Non-Condensing Natural Gas Tankless Water Heater, Up to 9.8 GPM, Indoor Installation, 199,000 BTU
Rinnai

Rinnai RE199iN Non-Condensing Natural Gas Tankless Water Heater, Up to 9.8 GPM, Indoor Installation, 199,000 BTU

Why we love it
  • Smart design saves energy efficiently.
  • Compact size fits small spaces.
  • Durable guarantees ensure long-lasting performance.
Main Highlights
  • Smart Design: Improved design of tankless hot water heater only heats when necessary to conserve energy; Speeds installation and enhances serviceability with a cleaner internal layout; LED screen provides service reminders and error codes
  • Never Run Out of Hot Water with this Compact Tankless Gas Water Heater: This non-condensing indoor tankless hot water heater from Rinnai is only the size of a small suitcase, but provides up to 7.6 GPM (6 fixtures at once)
  • Smart, Durable Design: Water heater includes 15-, 5-, and 1-year residential guarantee for heat exchanger, labor, and parts, respectively; See Controlr module for WiFi control (not included); See REP199iN for model with included pump
  • Professional Installation Recommended: Visit the Find a Rinnai PRO page on our website to locate a qualified technician in your area to install your tankless water heater; 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 for your home; Check our Ground Water Temperature Map to see if this heater is optimal for your region
9.1
Superb
Amazon Logo
9
9.0
Superb
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
9.0
Superb
Save 10%
Amazon Logo
10
8.9
Excellent
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
8.9
Excellent
Amazon Logo

Related Deals You Might Like for Tankless Gas Water Heaters

📊We scanned 283 products
🔍
We reviewed the most relevant Tankless Gas Water Heaters offers across Amazon and leading retailers, covering major brands and models. Our shortlist features trusted names like NOVIEEX, Rinnai, Rheem, APUS, FOGATTI, known for dependable quality and smart design.
⭐
To determine today's best Tankless Gas Water Heaters, 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 Tankless Gas Water Heaters 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 Tankless Gas Water Heaters ranking is updated regularly to reflect new releases and price changes—check back for the latest picks and deals.