Best Tankless Gas Water Heater

Best Tankless Gas Water Heater for Every Household

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Brenda Nyawara

Brenda Nyawara is an editor at Archute. She is a graduate architect with a passion for edge-cutting ideas in design, fashion, art and modern world interests.
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According to the US Department of Energy, tankless water heaters boost energy efficiency by 24-34% compared to the regular water heater storage tank, which heats and stores gallons of hot water. Therefore, investing in the best tankless gas water heater will save you money. We have listed excellent options and the crucial considerations when buying an ideal for your home.

What is a Tankless Water Heater?

Tankless water heaters also referred to as instantaneous, on-demand, continuous flow, or instant-on water heaters. The products instantly heat water as it goes through the devices and retains no water inside them except for what is in the heat exchanger coil. Besides, they deliver a constant supply of hot water when it's required.

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These water heater models don't have the standby energy losses that storage water heaters have therefore saving money. Now that we know what a tankless device is, let's check out the best models for your home.

1. EcoSmart ECO 11 Electric Tankless Water Heater

Sale
EcoSmart ECO 11 Electric Tankless Water Heater, 13KW at...
  • Endless On-Demand Hot Water; Consistent hot water when you need...
  • Save Space; EcoSmart tankless electric water heaters are 90%...
  • Save Energy; EcoSmart tankless electric water heaters are 99%...
  • EcoSmart ECO 11 Sizing; 13-kilowatt tankless electric water...

The now popular EcoSmart ECO 11 model can be evaluated as an optimal option for creating on-demand hot water solutions in conditions of limited space.

The CCS system of the EcoSmart ECO 11 has been beneficial for us. The never ending hot water supply is one of the many magnificent featuress that enables us to shower as long as we want to without slowing down on the hot water supply at all. It is also convenient that with the help of a small number of buttons we are able to set the temperature, which is comfortable for us.

Some difficulties where observed during installation especially on electrical needs that may be a challenge for some. Installing the cabling was also less difficult although it required a considerable amount of time and energy.

With regards to using it, we noted that it works well for lower flow applications. The external dimensions of this unit are 1500 x 760 x 760 mm which allows it to provide hot water for two showers at once in warmer climates, which makes it suitable for families or several people living in the house. We would consider it a worthwhile investment for those who need to replace their existing water heating system.

Pros:

  • Energy and space efficient
  • Ideal capacity for one or two adults
  • Offers optimal water pressure
  • Easy to install

Cons:

  • Limited output for simultaneous high-demand uses.
    Performance can vary based on climate and flow rates.

2. Rheem 18kW 240V Tankless Electric Water Heater

Sale
Rheem 18kW 240V Tankless Electric Water Heater, Gray
  • External digital thermostatic control with LED display (+/1...
  • Most advanced self-modulation, adjust power to meet hot water...
  • Durable Copper immersion two heating elements, field Serviceable....
  • Simple installation – bottom 3/4 inch NPT water connections
  • Threaded for easy replacement, simple installation, digital...

The Rheem 18kW Tankless Electric Water Heater is the best due to its ability to save space and heat water within the smallest amount of time.

Indeed the Rheem tankless system has really made a big difference in our home. The installation process was hassle-free; however, we needed to have our home prepared for 240V wiring. The first thing that we found impressive about the unit was just how sleek and non-intrusive it is, given its size, which it managed to occupy a rather small area without appearing to overshadow everything else.

The most unique experience is in the availability of hot water with no interruption at all. As compared to other systems that will be problematic if many showers are in use at the same time, this serves our family’s needs well. We lack spikes in power usage, especially during the rush hours or at nighttime as most families turn on all their gadgets.

We have been able to make savings in terms of energy bills on a monthly basis. This has relatively high costs of purchase for a start but the long-term effects such as reduced cost of maintenance and better performance make any investment in it worthwhile.

Pros:

  • Compact size allows for flexible installation.
  • Self-modulating technology reduces energy consumption.
  • Consistently delivers hot water on demand.

Cons:

  • Installation may require specific electrical setups.
  • Performance can vary with colder inlet water temperatures.
  • Higher upfront cost compared to traditional tank heaters.

3. EcoSmart ECO 27 Tankless Water Heater

Sale
EcoSmart ECO 27 Tankless Water Heater, Electric, 27-kW...
  • Endless on-Demand Hot Water; Consistent hot water when you need...
  • Save Space; EcoSmart tankless electric water heaters are 90%...
  • Save Energy; EcoSmart tankless electric water heaters are 99%...
  • EcoSmart ECO 27 Sizing; Refer to the sizing map. Requires 3x40...
  • Warranty and Certifications; Limited Lifetime Warranty on...

The recommended EcoSmart ECO 27 is an ideal water heater for those in search of the best tankless water heater.

To sum it up, we have been using the EcoSmart ECO 27 for several months now and receive hot water every time we need it. Whether we needed water for a shower or to fill the bathtub, this unit was able to deliver water without any stops. Its self-regulating system effectively balances the power with the required temperature, and it feels quite reliable.

Out of all these, the one that strikes me most is the space it saves. This is different from large water heaters that are usually placed on the floor, occupying a lot of space; this unit requires installation on a wall. In its use, we realized that it was most suitable for small houses or apartments.

Though these translates to a substantial saving in energy, the process of installation might be a challenge. We needed to make sure that the electrical system was compatible which can prove quite challenging and one might need to call an electrician if not well equipped with wires.

Therefore, the EcoSmart ECO 27 can be considered a great investment in modern hot water systems for large families as well as for people who need to replace old-fashioned hot water tanks.

Pros:

  • Provides endless hot water when needed.
  • Space-saving design; much smaller than traditional heaters.
  • Very energy efficient, potentially reducing electricity costs.

Cons:

  • Requires careful sizing to match your water needs.
  • Installation might need a professional, depending on upgrades.
  • Initial cost can be higher than conventional models.

4. Stiebel Eltron Tankless Water Heater

Stiebel Eltron Tankless Water Heater – Tempra 24 Plus...
  • CONTINUOUS FLOW – Advanced Flow Control patented technology...
  • SPACE & ENERGY SAVER – Its small, sleek white design saves...
  • EASY OPERATION – Electronic switch activates the hot water...
  • TEMPRA 24 PLUS – This specific model is 24kW, 240V, requires a...
  • WARRANTIES INCLUDED – Stiebel Eltron’s top-rated electric...

After using the Stiebel Eltron Tempra 24 Plus, we've been impressed by its reliable performance. This tankless water heater seamlessly supplies hot water on demand, eliminating the annoyance of running out mid-shower. The advanced flow control technology maintains temperature effectively, ensuring comfort without interruption.

We also appreciate the compact design, which freed up significant space in our utility room. Unlike bulky conventional heaters, this unit is sleek and easy to install. It does require an adequate electric service, but once set up, it operates quietly and efficiently.

On the downside, installation might be a hurdle for some. It’s best to have a knowledgeable electrician handle the setup, which can increase initial purchase costs. Additionally, while the system generally holds up well, we noticed that during peak usage times, the flow of hot water may be slightly reduced. Overall, if you're ready to invest a little more upfront, the Stiebel Eltron Tempra 24 Plus is a worthwhile upgrade for continuous hot water.

Pros:

  • Provides endless hot water with advanced flow control technology.
  • Compact design allows for space-saving installation.
  • Energy-efficient operation can lead to reduced utility bills.

Cons:

  • Installation may require professional assistance, which can add to costs.
  • High demand may slightly reduce flow during peak usage.

5. Rheem 240V Heating Chamber RTEX-13 Residential Tankless Water Heater

Rheem 240V Heating Chamber RTEX-13 Residential Tankless...
  • External adjustable digital thermostatic control with LED display...
  • Durable Copper immersion two heating elements, field...
  • Simple installation – 1/2 NPT adapters included; side 1/2 inch...
  • 99.8% energy efficient. External controls to adjust temperature...
  • Threaded for easy replacement, simple installation, digital...

When using the Rheem RTEX-13, we established that it significantly changed the way we utilized hot water. The constant supply has been considered very convenient particularly when usage is most especially high. One feature that we found favorable immediately is that the digital thermostat supports precise adjustments.

Installation is a rather easy affair due to the fact that 1/2 inch adapters are included with the kit. It poses no challenge during the setup stage, which is perfect for homeowners that want the upgrade without complications.

On the other hand, factors such as electrical needs should be given some thought. This unit requires a very heavy 60-amp breaker which could be a problem in most homes especially the older ones. Other than that, in situations that require heavy usage of the heater it might not be sufficient for people in colder regions.

Pros:

  • Provides endless hot water consistently.
  • Easy installation with included adapters.
  • Energy-efficient operation to lower utility bills.

Cons:

  • Requires substantial electrical capacity.
  • May struggle in colder climates with heavy demand.
  • Customer service experience can vary.

Factors to Consider Before Buying the Best Tankless Water Heater

1. Intended Use

Where do you plan to use your tankless gas water heater? Depending on the setup location, you can go for a whole-house tankless water heater or a point-of-use water heater. But of course, the former is more powerful than the latter.

Furthermore, whole-house tankless heaters provide enough hot water for an entire residence and have significantly larger flow rates and power inputs. On the other hand, point-of-use models are designed for use on a single fixture, with enough flow and power to heat water for one shower or sink.

2. Fuel Type

Before buying the best gas tankless water heaters, consider the fuel type. There are two types of gas fuel for these models; natural gas and propane gas. You can also get an electric tankless water heater. Let's go into detail on these types of fuels.

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i) Propane Gas 

It is the most expensive fuel option and is often not piped into residential homes. Therefore, it's more likely you will require a fuel tank for the water heater, which will take up space saved by the tankless design. However, propane tankless water heaters offer the best energy production, even outperforming natural gas. Also, they are ideal for recreational vehicles because of their liquid propane portability.

ii) Natural Gas

It is less expensive than propane gas and electricity. Besides, it's best for long-term investment due to the lower cost of natural gas, which will eventually pay for the unit. Also, natural gas is an excellent option for high-demand families.

However, natural gas is not easy to store. Also, we wouldn't recommend using it in an RV or at a campsite. Moreover, keep in mind that your home might not have natural gas connections, and if this is the case, extending a line into your house will raise the installation fee.

iii) Electric

Tankless electric water heaters are the least expensive option for initial purchase and installation. However, the high electrical requirements and lower total power production can quickly add up. One thing to remember about electric models is that their efficiency rating is about 10% higher than that of gas ones. Consequently, you can save more energy than with a gas model.

Conversely, depending on the current price of electricity vs. gas in your location, it may cost more. In addition, electric tankless water heaters have significant power requirements that an older home may not meet. Therefore, if the current electrical system doesn't meet the manufacturer's requirements, you will need a different water heater or pay more to upgrade the electrical system.

3. Flow Rate

Before getting the best tankless gas water heater, consider the flow rate, usually measured in gallons per minute (GPM). The manufacturer lists the measurements, which you can establish the maximum flow of hot water the heater can generate. Besides, each fixture in the house will consume a fraction of the water heater's total flow rate.

 For example, a sink uses roughly 1.5 GPM on average, whereas a shower requires about 3 GPM. Therefore, to operate both the sink and the shower at full capacity, the tankless water heater must have a flow rate of at least 4.5 GPM.

Conversely, households with more than four adults should invest in tankless water heaters with a flow rate of 7 to 8 GPM, while those with three or fewer adults should be fine with a flow rate of 3.5 to 5 GPM.

4. Condensing vs. Non-Condensing

i). Condensing

These tankless water heaters come with a condensing unit that absorbs and reuses the remaining exhaust heat before discharging a considerably cooler exhaust via the ventilation channels to the outside. Though this type is more expensive, it saves on ventilation material and achieves 98% efficiency.

iI). Non-Condensing

This type of tankless water heater will instantly exhaust the steam; therefore, ventilation materials must be able to tolerate high temperatures when hot steam passes through the their channels. Besides, these high-quality materials are expensive, and installation costs can be high.

The heat lost due to the quick venting of this steam results in an efficiency rating of around 80-85%. However, this type of water heater is less expensive to buy.

5. Safety Features

Before buying the best tankless gas water heater, it's wise to check for safety features. Keep in mind not all manufacturers make their tankless gas water heaters with safety features. In addition, you want protection from freezing and overheating if the unit is to be installed outsides or in a less ventilated area.

Some gas tankless hot water heaters have an automatic shutoff feature that usually shuts down the unit if there is excess water pressure or when it runs out of water. Besides, if you install the water heater in the open and have kids, a child safety lock feature on the controls will prevent accidents.

Frequently Asked Questions on the Best Tankless Gas Water Heater

1. What size gas tankless water heater do I require for a two-bathroom house?

As a general rule, the minimum size should be a 5 GPM flow rate for a two-bathroom house. For larger households, we recommend a 6 GPM flow rate or higher.

2. How do you install gas tankless water heaters?

Installation of a tankless gas water heater requires a professional plumber since a gas line needs to be safely connected to the unit and tested to confirm the connection does not leak fuel.

3. What are the cons of a tankless water heater?

The main setback of tankless water heaters is that they're substantially more expensive to buy (unit and installation) than tank-style heaters. On average, tankless water heaters cost three times as much as tank-style water heaters, including installation.

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About the author

Brenda Nyawara

Brenda Nyawara is an editor at Archute. She is a graduate architect with a passion for edge-cutting ideas in design, fashion, art and modern world interests.
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