Tankless gas water heaters provide an energy-efficient and continuous supply of hot water without the bulk of traditional tanks. These units instantly heat water on demand, making them ideal for homes looking to save space and utility costs. Below is a summary of the top-rated tankless gas heaters available with essential details to help you find the perfect model.
| Product | Brand | Max Flow Rate (GPM) | BTU | Indoor/Outdoor Use |
|---|---|---|---|---|
| Rinnai RX199iN Condensing Smart Sense | Rinnai | 11.1 | 199,000 | Indoor/Outdoor |
| Rheem RTG-70XLN-3 High Efficiency | Rheem | 7.0 | Not Specified | Outdoor |
| Orbek Natural Gas Tankless Water Heater | Orbek | 4.3 | 100,000 | Indoor |
| Rheem RTGH Series 8.4 GPM | Rheem | 8.4 | 157,000 | Indoor |
| Rheem RTG-95DVLN-3 High Efficiency | Rheem | 9.5 | Not Specified | Indoor |
Rinnai RX199iN Condensing Smart Gas Heater
The Rinnai RX199iN is a compact yet powerful tankless water heater offering up to 11.1 GPM, which supports simultaneous use of up to seven fixtures. It is highly versatile with an installation option for indoor or outdoor settings, powered by either natural gas or propane thanks to its Smart Sense gas control. Its condensing design boasts a very high energy efficiency with a UEF of 0.98.
Additional features include an intuitive user interface, a quick flush system for easy maintenance, and compatibility with WiFi control modules (sold separately). The unit’s small size makes it an excellent fit for compact areas while delivering consistent hot water flow for whole-home use.
Rheem RTG-70XLN-3 High Efficiency Outdoor Heater
This Rheem RTG-70XLN-3 unit offers reliable continuous hot water up to 7.0 GPM, sufficient for an entire household’s simultaneous needs like showers and dishwashers. It is designed specifically for outdoor installation, reducing indoor space requirements and enhancing home safety.
The heater emphasizes energy savings by only operating when hot water is needed and features a water-saving setting that could reduce water use by up to 1,100 gallons annually. Its efficient performance helps lower energy costs while maintaining comfort.
Orbek 100,000 BTU Indoor Tankless Gas Heater
The Orbek tankless heater is engineered for indoor use, delivering up to 4.3 GPM with a strong 100,000 BTU output, supporting 2-3 fixtures simultaneously. It features a durable, oxygen-free copper heat exchanger for improved heat transfer and corrosion resistance.
Safety features include dry combustion protection, overheat and water leakage protection, flame failure detection, and high pressure prevention. Energy efficiency is enhanced by adjustable heating modes to match seasonal needs and reduce costs.
Rheem RTGH Series 8.4 GPM Indoor Heater
The Rheem RTGH84DVLN3701171 model offers a flow rate ranging from 0.4 to 8.4 GPM with a temperature control range of 100 to 140°F, defaulted at 120°F. It features electric ignition for easy startup and uses a stainless steel construction to enhance longevity.
This model is ideal for indoor residential use where moderate to high hot water demands are present. Its temperature settings allow for comfortable customization to suit household preferences and seasonal needs.
Rheem RTG-95DVLN-3 High Efficiency Indoor Heater
This Rheem tankless heater provides continuous hot water at a flow rate of 9.5 GPM. Designed for indoor installation, it supports whole-home comfort even when multiple hot water outlets are in use simultaneously.
The unit is energy-efficient, operating only on demand to reduce usage and save on energy costs. It also includes water-saving settings, helping to conserve up to 1,100 gallons of water yearly without sacrificing performance.
Buying Guide for Tankless Gas Water Heaters
Choosing the right tankless gas water heater involves understanding several important factors to ensure efficient and reliable hot water supply:
Flow Rate (GPM)
Calculate your peak hot water demand by adding the flow rates of showers, faucets, and appliances that will operate simultaneously. Models range from around 3 to over 11 gallons per minute. Selecting a unit with sufficient capacity avoids shortages during high-demand periods.
Fuel Source: Natural Gas vs. Propane
Verify your home’s available fuel source. Many heaters support both natural gas and propane, but some models specialize exclusively in one. Confirm which fuel the heater supports to avoid installation issues.
Indoor or Outdoor Installation
Consider space availability and local building codes. Outdoor units save indoor space and reduce venting complexity but need weather protection. Indoor models require proper venting systems and occupy interior space.
Energy Efficiency and Certification
Higher energy factor ratings (like UEF) mean more efficient water heating, which saves on utility bills. Look for US safety and efficiency certifications such as CSA, UL listings, or ENERGY STAR labels for assured performance and safety.
Temperature Control and Features
Adjustable temperature settings allow precise hot water customization. Some advanced units offer smart controls, WiFi connectivity, and remote monitoring for convenience. Features like quick flush systems help maintain performance and extend lifespan.
Durability and Maintenance
Materials like stainless steel and oxygen-free copper in heat exchangers improve corrosion resistance and longevity. Check for available maintenance functions and warranty coverage to ensure long-term reliability.
By balancing your flow rate needs, installation preferences, energy efficiency, and safety features, you can select a tankless gas water heater that fits your household demands and budget.