The most efficient type of water heater is a tankless gas heater. These only use energy when you are actually running the hot tap and a natural gas water heater is one of the more affordable fuels.
However, even within this single category, there are many differences between each model. Some examples of aspects to consider before buying a new water heater are its energy efficiency, flow rate, anti-scale devices, materials, whether it has a digital display and the warranty. To help you find the best water heater for your needs we have put together this list of gas water heater reviews and hopefully give you all the information that you need to know.
Top 5 Best Natural Gas Water Heaters
To narrow down your search for the best tankless gas water heater, here is a top 5. Or, scroll further down to the buying guide to compare even more models on your own.
1. Best Overall: Takagi T-H3-DV-N
|Flow Rate||10 GPM|
|Dimensions||11.2 x 17.8 x 24.9 in|
Takagi is a highly respected water heater brand and looking at this model it is easy to understand why it is so trusted by consumers. Despite being a compact size, this tankless gas water heater is powerful enough for up to 4 separate bathrooms in a warm climate or 3 bathrooms in a cold climate.
This is a highly efficient model that uses commercial-grade copper alloy instead of stainless steel which allows for faster heat transmission. However, the manufacturer chose to keep using stainless steel in its secondary heat exchanger because this material is less prone to corrosion.
The warranty is a good reflection of the quality that you are getting. Tagaki offers 15 years warranty for the heat exchanger and up to 5 years warranty for other spare parts, both are generous, making it our overall best hot water heater.
It is Energy Star certified with an impressive index of .95%, a high score. It also has a high flow rate of up to 10 gallons per minute which explains why it is perfectly capable of delivering to 4 fixtures.
A final advantage of this model is how quietly it operates. Its noise level is rated as low as 55 decibels which is comparable to the hum of an energy-efficient refrigerator.
- Sleek compact design
- High capacity
- Very energy efficient
- Pricier option
- Warranty only applies to professionally installed pieces
2. Best Control from a Distance: Rinnai V Series HE
|Flow Rate||3.9 GPM|
|Dimensions||14 x 23 x 9 in|
The unique selling point of this Rinnai V series model is the mobile app that lets you change the settings from wherever you are as long as the heater is connected to your home’s wi-fi connection. This is a great tool for monitoring while you are away and quick adjustments whenever needed.
You can also adjust the temperature on the heater itself and check the current temperature in both Fahrenheit and Celsius on its digital display. However, for more advanced settings you need to make use of the Control-R 2.0 application on your smartphone.
Rinnai rates this model’s flow rate at 3.9 gallons per minute with a groundwater temperature of 57°F. It also recommends a maximum of three connected fixtures to ensure that you have a continuous supply but you can upgrade to the V94i which has a flow rate that is high enough to handle up to 4 connected fixtures.
Another advantage of choosing this option is the generous warranty that spans over a decade with residential use. Included in the warranty is labor up to the first 12 months, spare parts up to the first 60 months and heater exchanger up to the first 180 months and therefore on our best gas water heater list.
- Connects to Wi-Fi for control via a mobile app
- Extensive warranty
- .82 Energy Star rating
- Ultra-low NOx
- Not suitable for cold climates
- Requires professional installation
- Poor packaging – prone to faults out of the box
3. Best for Small Homes: Eccotemp FVI12-NG
|Flow Rate||3.5 GPM|
|Dimensions||4 x 15 x 24 in|
Looking for something smaller for a single bathroom and that does not take up too much space in your apartment? Then this Eccotemp, is the best water heater for you, measuring only 4 x 15 x 24 inches will fit in nicely.
On top of that, this compact home appliance comes at a very affordable price so it is also great for those on a budget. Despite its low price, it performs very well with a flow rate of 3.5 gallons per minute.
One important thing to note about this natural gas water heater is that it still requires electricity to run. Even though it heats using natural gas, the internal exhaust fan and the digital display run on regular electricity so you need to hook it up to an outlet.
This is one of the easier models to install so if you are handy enough you could install it yourself. The package comes with a stainless steel horizontal vent kit which you should install slightly sloped to prevent corrosion.
On the heater itself, you find the digital temperature display and the turning knobs for manually adjusting the temperature and gas regulator.
- Compact size
- Simpler installation compared to other models
- Only suitable for single fixture connection
- Poor customer service
4. Most Splurge-Worthy Model: Rinnai RUC98iN Ultra Series
|Flow Rate||9.8 GPM|
|Dimensions||10 x 18.5 x 26 in|
If you are looking for one of the best gas water heaters, note that it is also the most expensive option in our top 5, this is one of the biggest with the most impressive specs far beyond the other products. If you have high demands for your supply then this is your best bet and is at the top of all the best water heaters.
The minimum to maximum gas burn rate is wide from 15,200 – 199,000 BTU with an equally wide flow range of anywhere between 0.25 and 9.8 gallons per minute. With this capacity you are ensured hot supply in several bathrooms at the same time, making it perfect for larger households.
Rinnai markets this product as one of their most energy-efficient models with 95% thermal efficiency on both natural gas and propane (alternative available). For residential use, it can be installed with a temperature range between 98°F – 140°F but for commercial purposes, it is capable of reaching up to 185°F.
You will need a professional to come and install this home appliance but this does provide you with the much-appreciated warranty. Consumers will receive a 12-year warranty on the heat exchangers, 5 years warranty on spare parts and a 1-year warranty for professional help with the option to expand this to 5 years.
- High flow rate
- Suitable for both residential and commercial use
- Wide temperature range
- Energy efficient
- Takes longer to reach the desired temperature
5. Best Budget Choice: Vevor 12L with Shower Head
|Flow Rate||3.2 GPM|
|Dimensions||14 x 6 x 25 in|
The best gas hot water heater on a budget. It is possible to get a good tankless heater on a small budget as shown by this Vevor model that even comes with a shower kit as an extra. However, that does not mean that this is the type that you install in the shower – it still needs to be placed in an area with proper ventilation.
This is a good choice for colder climates since it has anti-freezing functionality. On the opposite side of the spectrum, it is pre-installed to prevent overheating and includes an automatic shutoff after 20 minutes, making this a safe design for the whole family.
Another reason to love this Vevor product is that it works just as well with low pressure which can come in handy if you don’t have a pump or an unstable flow rate throughout the house. One disadvantage of this product is that it is not as energy efficient as the other models on this list with a rating of around 81%.
Considering its specs, the Vevor is best for a single bathroom household since it does not have the biggest capacity and energy efficiency. On the other hand, it is a very respectable design that outperforms its very low price category.
- Very affordable
- Functions off-grid with batteries
- Lower flow rate
- Could be more energy efficient
Natural Gas Tankless Water Heater Buying Guide
Now you have seen our gas water heater reviews here is a guide of what to think about, if you take your time to do a bit of research on what would be the most appropriate heater for your household, you should be able to find one that lasts you well over a decade. Read on to find out all you need to know about this highly efficient type.
How Does It Work?
A tankless water heater is also known as an on-demand heater because the cold supply is instantly warmed up as it passes through. The cold supply enters the main body on one side and hot supply comes out on the other side.
Inside the main body are heating elements, often made of copper coils but there are variations. These elements become hot through a natural gas burner or electric power source, depending on the type.
Since the water warms up as it moves, there is no need for a tank. This is why this type is more energy-efficient, there is no need to heat up more than is actually used.
Why Choose This Type
If you are looking to lower your monthly electricity bills then this is a smart choice. Tankless heaters are often reported as 50% more energy efficient so they do have a significant impact.
The compact size makes this a space-saving solution that is perfect for apartments and smaller houses. Although there are many models that are more expensive than a storage tank heater, you are still able to find good reliable budget options.
One of the main advantages of an on-demand model is that the flow is continuous, theoretically endless. So, if you have a high need for a large supply, like in a large household or for a hot tub, this is the most reliable option.
Things to Remember
There are two types of tankless heaters, one that uses natural gas or propane and one that is electric. However, despite this distinction, the gas type might also still require an electrical supply.
This is because even though the supply is heated through a gas burner, the other features on the appliance like the digital display are electric. So, check the product description carefully if you are looking for a unit that is truly off-grid.
Many units have a lower flow rate which in practice means that the supply to different parts of the house at the same time might not work. Check what the capacity is of the unit and how many fixtures it can handle at the same time or you might need to take turns running different appliances.
Ventilation is very important so it is best to have a professional come and install the unit in a safe space with the correct safety precautions. Installation can be tricky and installing it yourself might default your warranty.
There are several types of water heaters that you can categorize by whether it has a tank or not and its energy source. Below are the different alternative types.
Electric tankless heater: uses heating elements to instantly heat as it moves through the unit.
Storage tank heater: heated inside the tank and so the amount is limited to the volume of the tank.
Solar-powered heater: uses solar energy to heat inside a tank. A great off-grid alternative that has very low running costs.
Heat pump: uses heat from the earth and air to heat inside a tank. A more complicated option that only functions optimally in certain regions.
Condensing heater: uses the residual heat from a home that uses natural gas as its main energy source to heat the water inside a tank.
Read up on each alternative, refer back to your current water heater and decide which type is most suitable for you.