10 Best Natural Gas Hot Water Heater of December 2025

• V65iN HE High Efficiency Tankless Hot Water Heater - Natural Gas: Indoor Installation Only
• Up to 6.5 GPM hot water flow rate (varies by groundwater temp)
• Control-R 2.0 mobile app features timers and schedules throughout the day and allows you to remotely put the system into vacation mode.
• Endless hot water for your entire home
• Residential Factory Warranty - 120 months (heat exchanger), 12 months (labor), 60 months (parts)

Rinnai

• INDOOR installation only. Fuel Type: NATURAL GAS.
• Concentric or PVC venting option
• Up to 0.96 Energy Factor/Up to 0.92 Uniform Energy Factor
• The space-saving design allows Indoor Installation type
• Ultra low NOx emissions
• 199,000 max BTU

Rinnai

• [Ease to Use] For whole home on demand indoor use with safe, efficient power ventilation , perfect for any small homes, cabins or apartments.
• [Modern Design] Exclusive color digital temperature display for easy to read.
• [Saving More Energy] Eco and Full gas switch for energy saving and get ideal hot water temperature.
• [More Safety] Flame-out protection, anti-freezing protection, over-heating protection, air flow pressure switch protection to ensure the safety.
• [Controls Water Temperature Easily ] Uses standard 1/2" NPT water fittings and is equipped with easy to use manual water temperature controls.

CAMPLUX ENJOY OUTDOOR LIFE

• Blue Diamond glass coating provides superior corrosion resistance to industry-standard glass lining
• Self-powered electronic gas valve uses thermopile to generate power needed to operate the electronic gas control without requiring external power
• Internal microprocessor provides enhanced operating parameters and tighter differentials for precise sensing and faster heating response
• Dynaclean diffuser dip tube helps reduce lime and sediment buildup, maximizes hot water output; made from long-lasting PEX cross-linked polymer
• Meets all current regulations set forth by the National Appliance Energy Conservation Act (NAECA)

A. O. Smith

• Natural gas tankless water heater for indoor installation only
• Up to 9.4 GPM hot water flow rate (varies by groundwater temp)
• Circ-Logic technology allows you to set recirculation patterns that coincide with your typical habits.
• 10,300 BTU (Minimum) / 199,000 BTU (Maximum)
• Residential Factory Warranty - 120 months (heat exchanger), 12 months (labor), 60 months (parts).
• Endless hot water for your entire home, right when you need it.

Rinnai

• Modulates heat output in response to the flow rate of water running through the unit.
• Power vented directly vertically (rooftop) or sideways (wall) via Stainless Steel CAT III Flue 3.5" Diameter Included (20")
• NATURAL GAS - European Model - Digital Display is in Celsius
• Delivers 6.6 gpm of hot water with a 35°F Instant Temperature Rise (Equivalent to 5.5gpm with a 45F temp Rise)
• Certified for Installation in Manufactured (Mobile) Homes Pure Copper Heat Exchanger

GASFLEX

• Endless hot water for your entire home
• V65eN HE High Efficiency Tankless Hot Water Heater - Natural Gas: Outdoor Installation Only
• Up to 6.5 GPM hot water flow rate (varies by groundwater temp)
• Control-R 2.0 mobile app features timers and schedules throughout the day and allows you to remotely put the system into vacation mode.
• Residential Factory Warranty - 120 months (heat exchanger), 12 months (labor), 60 months (parts)

Rinnai

• RU199iN Sensei SE+ Super High Efficiency Tankless Hot Water Heater - Natural Gas: Indoor Installation Only
• Up to 11 GPM hot water flow rate (varies by groundwater temp)
• 15,000 BTU (Minimum) / 199,000 BTU (Maximum)
• Circ-Logic technology allows you to set recirculation patterns that coincide with your typical habits. Hot water is available when you need it!
• Endless hot water for your entire home
• Residential Factory Warranty - 120 months (heat exchanger), 12 months (labor), 60 months (parts)

Rinnai

• Digital Temperature Display
• Compact design saves space and allows for easy installation just about anywhere
• Does not require electricity (operates with 2 D Cell battery)
• Only uses gas while water is flowing
• Saves water and up to 60% less electricity than conventional tank water heater, making it cost effective and

MAREY

• Rated for 2-3 applications used simultaneously means that taking a shower and running two sinks at the same time is effortless. The Eccotemp 20H is ideal for normal hot water heating applications in ANY size residential single-family home.
• Best in class 10-year product warranty offers peace of mind that the Eccotemp 20H will withstand the time and use you need. The Eccotemp 20H can be complemented with our patented one of a kind EZ-Flush descaling kit to ensure your tankless water heater is running at maximum efficiency all year long.
• Rated at 6.0 GPM at 150,000 BTU with a temperature rise of 38 degrees this ultra-efficient tankless water heater is ideal for just about every single-family home in the US and Canada. With Advanced incoming and outgoing water temperature sensor technology you always have total confidence when it comes to safety.
• CSA certified for installation in the US and Canada. This tankless water heater meets and exceeds all safety and efficiency requirements according to the DOE. With an Energy Factor Rating of .83, you can have peace of mind knowing this tankless water heater is ideal for individuals looking to save money.
• Advanced Generation 3 Computer board with high performance processing and smart adjust technology built in. Our proprietary developed programming meets and exceeds today’s consumer demand needs.

Eccotemp