Best Gas Tankless Water Heaters – Reviews & Guide 2020

A water heater is only useful when it can supply adequate hot water to the users instantly at any time of demand, and takes a little space in either the kitchen or the bathroom or the both. These are features of the best form of a tankless gas water heater.

Sadly, getting the right product becomes overwhelming and stressful with lots of factors and products to consider.

But no need for worries, this article has written up seven best gas tankless water heater you can get with a step-to-step buying guide for it.

Top 7 Gas Tankless Water Heaters

Rinnai RUC98iN Series Natural Gas Tankless Water Heater

Rinnai RUC98iN is the most suitable water heater for commercials companies or organizations, extended families, public places or bars. This is because you can use it with your kitchen’s faucets and bathrooms simultaneously without slowing down its efficiency or damaging it. Also, it is a unique water heater with the highest water flow rate. It has a high flow rate of 9.8 gallons of water per minute. That is not all about it.

Furthermore, you can operate it easily without going near it from afar with just a remote control. This makes it safer compared to all other water better. With its insulation valves and pressure relief valve, this product is an efficient and reliable one. More importantly, it is expensive so a person on a budget might not be able to purchase it. It is a long term durable model. It comes with a variable warranty. For home use, it has a 12-year warranty on the heat exchanger and a 5-year warranty on the parts. Also, for commercial use, it has a 5-year limited warranty on the heat exchanger and a 2-year warranty on the parts.


  • The best model for commercial uses
  • A high water flow rate
  • A safe water heater
  • Comes with insulation valves and relief valves
  • Long term durability


  • Expensive
  • Complicated installation procedures

Excel Tankless LPG Has Water Heater

Excel water heater comes in a sleek and beautiful design that makes it an attractive one for all users. For people looking for a tankless water heater with a low price for those on a budget, then this is the best option. It delivers your hot water instantly without any delays. All you need is to open the water heater tap. It uses less pressure to get the water hot, unlike most water heater.

You can install this product all by yourself without ordering for the service of a plumber. This helps to save some amount which you would have paid for the plumber. This model is a suitable one for hunting, RVs, boating, camping, etc. With just a weight of 20 pounds, it can be carried from one place to another without much stress.

It is a compact design product that fits most times into smaller homes. More importantly, it comes with a flow rate of 1.6 gallons per minute. It is also a vent free model and features copper heat exchange which protects the wire from damaging easily.


  • A vent free model
  • Features a copper heat exchange
  • Provides not water instantly
  • A unique indoor water heater
  • Lightweight


  • Expensive
  • Complicated installation processes

Takagi T-KJr2-IN-LP Indoor Tankless Water Heater

If you are in search of a water heater with a small size that can fit into a small space apartment, then this model is the best option for you. It has a high water flow rate of 6.6 gallons of water per minute. Takagi Indoor tankless water heater is an efficient one, so you don’t have to worry about running out of hot water.

This product also helps to save up some cash spent on the supplying of electricity as it uses less energy rate. Moreover, it can also be used to provide pressurized water to both the kitchen and the bathroom at the same period time. You don’t need to worry about regular cleaning of this model as it does not get stain easily and it is easy also to maintain.

Lastly, this product features stainless steel that prevents the design from fading or staining. For home use, it has a 10-year warranty on the exchanger heat and a 3-year warranty on the part, while for commercial use, it has a 5-year warranty on the exchanger heat and a 3-year warranty on the parts.


  • The best model for a small apartment
  • Features a stainless steel
  • Easy to clean and maintain
  • Support a bathroom and kitchen simultaneously
  • Effectiveness and efficiency


  • Most times have complicated installation processes

Rheem RTG-64DVLN Prestige Low Nox Infoor Direct Vent Condensing Tankless Natural Gas Water Heater

Rheem RTG-64DVLN is the best direct vent condensing tankless natural gas water heater. This model combines its pricey nature with its outstanding performance. It supplies constant water supply to you so you would never worry of getting out of water hot. Also, it takes only small spaces and due to this fact gives the user the room to install other valuable material at home.

With 6.8 gallons of water per minute, this model works efficiently and effectively in supplying adequate hot water for the users. It has low Nox version. This product’s temperature level can be adjusted to suit the taste of any user. On another hand, it comes with digital remote control that gives a user easy access to the product without going near it or touching it. This also makes it a safer model.


  • A constant supply of hot water
  • Compact design
  • A high flow rate of 6.8 GPM
  • Features a low Nox version
  • Comes with a digital remote control


  • Limited lifetime warranty

Noritz NRC661-DV-NG Indoor Condensing Direct Tankless Hot Water Heater 6.6 GPM- Natural Gas

For users in search of a luxury gas tankless water heater, then this must be what they are looking for. This model comes in a pricey but combines efficiency with expenses. That is not all. It helps to save up a lot of gas as it only uses 15% KWH or less while pressurizing water. It supplies hot water regular to the user any time of demand. With this product, you don’t need to spend extra cash calling for installation as you can install it without ease.

All you need is the step-by-step instructions that come along with the product. It can supply adequate hot water to two bathrooms or kitchens. Energy Star certified Moritz due to its undoubtedly energy efficiency. It has a variable warranty. For home use, it comes with a 12 years warranty on the exchanger heat and a five warranty on parts and one year on labor.


  • Uses less gas or electric
  • Long term durability
  • Easy installation procedures
  • Supports two bathrooms or kitchen
  • Constant hot water supply


  • Costly

Eccotemp i12-NG Tankless Water Heater

The Eccotemp i12-NG comes in a new, unique revolutionary design, which makes it different from most tankless water heater available out there. This tankless water heater features a modern, sleek black gorilla glass casing to add to your overall home aesthetic.

With its automatic temperature controls, users can precisely get their water at a specific temperature. Plus, its touchscreen with a great user-friendly interface and an LCD temperature display to show not only the precise temperature but also the GPM flow.

Talking about GPM flow, Eccotemp i12-NG Tankless Water Heater comes with an impressive 3 GPM. It is fired using a liquid Propane. The i12-NG is specially designed, for homes with average hot water demands at the same time, to supply them with small to medium hot water production.

What’s more? This tankless water heater is a perfect choice for smaller homes, cottages, and vacation cabins. It includes a horizontal stainless steel vent kit, which makes installing this product a breeze. Also, it comes with a 120 Volts Ul to power both the LCD digit display and internal exhaust fan. Last, but the least, Eccotemp i12-NG Tankless Water Heater is a go-to for people looking for an energy efficient appliance, as it only uses about 2W idol and 1.07A during its operation.


  • Comes well for small homes
  • Automatic temperature controls
  • LED display
  • Quick and easy to install
  • Child lock technology
  • Power saving


  • The exhaust pipe might get stuck

Excel Pro Tankless Gas Water Heater

This compact, yet robust tankless gas water heater using a gas input as high as 140,000 BTU per hour. This model provides the most hot-water needs of most American apartment or home ranging from small to medium size.

Specially designed to do almost anything a 40-gallon tankless water heater is meant to do and even better. This wall-mounted Excel Pro is engineered to function flawlessly with radiant floor or hydronic baseboard heating applications. Plus, provide hot water to all domestic plumbing appliances and fixtures. It also features an LCD control allowing users to get a precise water temperature. All you have to do is set the output temperature.

On top of that, it makes use of a pure copper heat exchangers similar to most top-of-the-line tankless gas water heater brands such as Noritz, Rheem, Takagi, and Rinnai. It offers incredible compactness allowing you to install this product anywhere – 14.5 inches x 23 inches x 5.5 inches and with a capacity of 6.6 gallons per minutes, which one of the highest you can get on the market. Also, it’s capable of a 35F degree rise in temperature instantly. Besides that, this product is certified for installation in Manufactured (Mobile) Homes Pure Copper Heat Exchanger.


  • 6.6 gallons per minutes
  • Compact
  • Ideal for small homes
  • Modulate heat output


  • May have to use tape for tight, waterproof connections

Gas Tankless Water Heater – Buying Guide

Since your choice is to get the best form of a gas tankless water heater, there is some task you have to take. But fortunately, this article has made the job an easy one by writing this buying guide. This guide gives you knowledge on some features you have to look for in the model of this water heater before you get the best. Also, it entails the various factors a user must consider before going for a gas tankless water heater. Some of these are:


A buyer always purchases what gives him or her comfort and relief. The same idea applies to a user in purchasing a tankless water heater. All you need is to know the length of your place of installation. Of it is a bathroom, you would be getting a water heater with medium size while if it is a kitchen that most time is always crowded, you need to give a compact design to fit into these bathrooms or kitchens.

Condensing vs. Non-condensing

This is another major factor to put into consideration. While a condensing water heater has easy installation procedures and if it helps to save a lot of money, non-condensing are cheaper and fit into smaller spaces easily while compared to other gas tankless water heater. Also, condensing provide adequate hot water supply to its users just using little level of energy, while the non-condensing model is suitable for outdoor activities such as hunting camping, etc. Lastly, non-condensing models are in lightweight form and are dangerous if used inside the house.


It might be difficult to get the best form of gas tankless water heater without considering the installation procedure of the product. This may sound or look minor to you, but it is as important as other factors. A model with easy installation procedures does not only help to save time fixing it up, but it also helps to save money which ought to have been paid to a plumber if it had come in complicated installation processes. It is important to know that products which are installed by experts most time stay for an extended period compared to ones installed by the users.


It is also important to consider this factor. This is because this shapes the buying power of a user. For example, a luxury gas electric water heater can only be afforded by upper-class citizens or people that earn a lot of money. So before going for any model of this tankless water heater, it is essential to put these following factors into consideration.