Contents
- Best Tankless Gas Water Heater Reviews
- Gas vs Electric Tankless Water Heater
- Tankless Gas Water Heater Types
- How Does a Gas Tankless Water Heater Work?
- Gas Tankless Water Heater Buying Guide
- How to Install a Gas Tankless Water Heater
- Maintenance of Gas Tankless Water Heaters
- FAQ About Gas Tankless Water Heaters
- Tankless Gas Water Heater Comparison Chart
- Wrap Up
Nowadays, when it comes to building new homes (and renovating older ones), the first phrase that comes to mind is energy efficiency. Of course, besides the best utilization of energy, the thing we tend to worry about the most is cost efficiency, which is perfectly logical. Having that in mind, we will bring you closer to the topic, and help you pick the best tankless gas water heater for your household.
The choices vary, and there are a lot of important facts that you should know and consider, before installing or retrofitting a new tankless water heater. We will go through everything you need to know, and through differences between similar-working models as well.
So, we invite you to stick around and consider our buying guide, as well as our tankless gas water heater reviews, that we will briefly present for 12 of the most popular models in the following sections.
| PRODUCT | DETAILS | ||
|---|---|---|---|
 | Takagi T-KJr2-IN-NG |
| View On Amazon |
 | Rinnai RUC98iN Ultra Series |
| View On Amazon |
 | Rheem RTG-84XLN 8.4 GPM |
| View On Amazon |
 | Eccotemp i12-LP |
| View On Amazon |
 | Aquah Indoor 16L |
| View On Amazon |
 | Takagi T-KJr2-OS-NG |
| View On Amazon |
Best Tankless Gas Water Heater Reviews
1. Takagi T-KJr2-IN-NG
First off, we have an indoor unit that runs on natural gas. It is a well-designed, middle-class, tankless water heating unit with a BTU rating of 140,000. This particular unit is the smallest one from this manufacturer, and they advise it to be used in small apartments or condominiums.
This unit exerts a max flow rate at 6.6 GPM/25 LPM, which should be more than enough for a medium-to-small sized apartment, or a single floor of a bigger house. The connection valves are placed at the bottom of the unit, and 4-inch category III stainless steel venting is required for it to operate.
Mid-range models like this one will get the job done, and this particular model has the energy factor efficiency of 0.81 – 0.83, which is excellent considering its compact size. It also has inlet and outlet thermistors for constant monitoring of the temperature.
Read More: Takagi T-KJr2-IN-NG
2. Rinnai RUC98iN Ultra Series
Here we have a big-league player, a heftier and more powerful unit, with a price that shows it. Weighing in at about 80 pounds, and with a max BTU rating of 199,000, this natural gas water heating unit is up to any challenge you might have. Modernly designed, with a small, discreet LCD monitor and control panel, this model is equipped with a dual vent exhaust system, making it even more efficient, because you can choose between concentric and PVC venting options.
The energy factor of efficiency goes up to 0.96, or 0.92 on the uniform energy factor scale, making it ultra-efficient. You can use this model for a bigger home, or even for commercial purposes. It is a bit pricey, but it sure delivers great results.
The manufacturer is especially proud of all the global regulations this unit meets, so, there will be no need for additional modifications, making it perfect for new homes and retrofitting.
Read More: Rinnai RUC98iN Ultra Series
3. Rheem RTG-84XLN 8.4 GPM
Next up, we have an outdoor only unit from Rheem. Being that it is an outdoor unit, there will be less work on the installation itself, which is a plus. Additionally, more storage space will be available in the garage/bathroom.
As a natural gas tankless water heater, this unit is stronger than the previous, clocking at 8.4 GPM/31.8 LPM at a 35-degree Fahrenheit (19.44-degree Celsius) rise in temperature. This model is a bit larger and can cover a whole medium sized household with more than one bathroom.
A nice additional feature is the UMC-11 remote control and a 10-foot thermostat wire which comes included with the unit, for more convenience. Considering that it is an outside only unit, remote control is a quality-of-life feature not to be underrated. Also, because the unit is stationed outside, no drilling for the exhaust gasses will be necessary, and no pipes need to stick outside of your house`s wall.
Read More: Rheem RTG-84XLN 8.4 GPM
4. Eccotemp i12-LP
Now it is time to dive in into the second type of gas tankless water heaters: propane-powered models. The very first in this group is the beautiful, futuristically designed model from Eccotemp. This model is an indoor one, and we were amazed at how well it fits inside the house. It is compact, and the black LCD screen makes it look really modern.
When it comes to power, it is rated at 3 GPM/11.36 LPM, which may not sound like much, but it is surely enough to supply a small-to-average household with hot water on demand. Additionally, to further save money, this unit does not require a pilot light for ignition. It also has a fully automated temperature control system with a power-saving mode.
It uses standard 1/2-inch water fittings and supports a horizontal setup style, making it extra convenient, even for retrofitting into older homes.
Read More: Eccotemp i12-LP
5. Aquah Indoor 16L
A model of medium-range efficiency and incredibly simple design. This indoor propane tankless unit is designed to support a standard house layout of a single bathroom, restroom or kitchen individually or at the same time depending on use. With the energy efficiency rate of 0.85, the BTU rating goes up to 109,260, making it an average unit.
When it comes to the flow power, this model can achieve 45-degree F (25-degree Celsius) temperature rise at the flow rate of 4.3 GPM/16.28 LPM. The layout of piping and wiring is vertical (bottom side), and it supports the standard valves, as well as the older types, which is extra convenient for older objects.
This unit is quite easy to install, and it has an automatic electrical pulse ignition, meaning that it doesn`t require a standing pilot light, but 2 D batteries or a 120V alternative current adapter.
Read More: Aquah Indoor 16L
6. Takagi T-KJr2-OS-NG
Here we have the outside-only counterpart of the first model reviewed. It is a natural gas tankless water heater compact enough that it will be almost invisible on the side/backside of your house. It also has all of the pipe connectors on the bottom side, and because it is an outside model, no exhaust pipe is needed. Plus, it takes no inside storage space.
The BTU rating ranges from a minimum of 19,500 to a maximum of 140,000 BTU. The flow rate clocks at a maximum of 6.6 GPM/25 LPM, which makes it powerful enough to substantiate an average sized house. The energy efficiency factor is the same as the inside unit, a total of 0.82.
This manufacturer went the extra mile and built in an anti-freeze module, ensuring that it can withstand the coldest of environments.
Read More: Takagi T-KJr2-OS-NG
| PRODUCT | DETAILS | ||
|---|---|---|---|
 | Rinnai V65EN 6.6 GPM |
| View On Amazon |
 | Eccotemp L10 |
| View On Amazon |
 | Rinnai V65IN 6.6 GPM |
| View On Amazon |
 | Camp Chef Triton 10L |
| View On Amazon |
 | Rinnai V65IP 6.6 GPM |
| View On Amazon |
 | Takagi T-KJr2-IN-LP |
| View On Amazon |
7. Rinnai V65EN 6.6 GPM
Coming from the same, quite a popular manufacturer, this gas tankless water heating element is considered a light-to-medium-duty one. It is an outdoor unit, which right away means no exhaust pipes will be needed in your walls.
The BTU rating of the unit comes to a maximum of 150,000, with an energy efficiency factor at 0.82. The model is compatible with older 1/2-inch gas line connectors, so it is also a recommended model in the case of retrofitting.
As a standard natural gas unit operating at a maximum of 6.6 GPM/25 LPM, it can cover an average size household with continuous hot water demands. The default version is fitted for 120V systems, but modifications can easily be made.
This compact unit meets every standard and regulation for the worldwide market, and its sleek white design makes it almost camouflaged on the outside wall of a standard looking house.
Read More: Rinnai V65EN 6.6 GPM
8. Eccotemp L10
From the same manufacturer comes a somewhat unique outside propane-powered tankless water heating model. They advertise this model as an ideal appliance to carry to camping trips, and for around the house. It is an extremely portable model that uses a standard propane tank as a power source.
The portable options shine when it comes to extra features this unit provides. It has a 20-min Safety Shut-off system installed, so no extra waste occurs. Additionally, it has a 45-degree Safety Tilt Switch on board, adding to the portability factor. It also comes with a gas regulator and a hose, showerhead and a garden hose adapter.
As you might have guessed so far, the power this unit can exert is not that great, but it will provide it at any location. The model is rated at 2.6 GPM/9.84 LPM, with an achievable temperature range of 50-140 degrees F (10-60 degrees C).
Read More: Eccotemp L10
9. Rinnai V65IN 6.6 GPM
To prove that the previous model is quite popular, we got to test out the inside version of it. Equipped with similar technology, this Rinnai model uses natural gas as the main fuel source, but has the option to be recalibrated and modified to use propane.
Regarding the heating power, it is practically the same model, with the exception of a more adaptive GPM system, ranging from 0.26 to 6.6 GPM (1 to 25 LPM). Keep in mind that this is strictly an indoor unit, so some drilling to make an exhaust pipe will be necessary. But the compact size makes up for it.
The energy efficiency rating of the model is 0.82, and this unit meets global and US code standards. The BTU rating stays unchanged in regards to its outside counterpart, at 150,000 BTU for natural gas.
Read More: Rinnai V65IN 6.6 GPM
10. Camp Chef Triton 10L
As the name of the manufacturer suggests, this model is the perfect camping addition. A portable propane tankless water heater unit, which can easily be carried to outdoor activities. Its size covers only 10 liters, but the unit does exert an astonishing 2.6 GPM/9.84 LPM for its dimensions.
The design of the model is rectangular and fairly simple. The heating unit automatically ignites when water is turned on, and the ignition process doesn’t require a pilot light but uses 2 D batteries instead. Even though the unit is made to be portable (it has a carrying handle), it also comes with mounting notches, if you wish to mount it on a wall.
We have to admit, it is not a powerful unit, per se, but it makes up the lack of power in portability and price. It is affordable and designed to be as ergonomic as possible. Its portability also makes it a perfect addition for a recreational vehicle or a camping house.
Read More: Camp Chef Triton 10L
11. Rinnai V65IP 6.6 GPM
One of the most powerful propane powered tankless water heaters on this list. This indoor model brings serious heating power, almost as if it was a natural gas one. Minimalistic, white design makes it blend in perfectly with any type of kitchen or basement.
The maximum BTU this model brings goes up to 150,000, and the 6.6 GPM/25 LPM makes it powerful enough to provide hot water for the whole house. It does require an exhaust system to be installed above the unit, but it is worth the trouble. This Rinnai model is the most expensive propane model on this list, and if you have to go with a propane option in your home, this model will fulfill all the needs you may have. So, at a higher price, you will get adequate service with this unit. And, as mentioned before, the Rinnai stands tall when it comes to fitting into any global regulative system.
Read More: Rinnai V65IP 6.6 GPM
12. Takagi T-KJr2-IN-LP
Last, but certainly not least, we have a familiar model from Takagi. This indoor, propane tankless water heater is made in the image of the first model on the list. A great efficiency rating of 0.8 at the max of 140,000 BTU makes it a great addition to your household if there is not any natural gas line available, or you have a stable propane installment in your yard.
The wiring and pipes are vertically set up, with a 4-inch category III stainless steel venting required for it to operate, since it is an indoor model. The maximum flow rate of this unit is 6.6 GPM/25 LPM, similar to its natural gas counterpart. The electronics and the combustion system are powered via a 120V AC power cord, and the water connection is a standard ¾-inch valve.
This model is one of the strongest propane-powered in its class, and it is not to be underestimated. It is powerful enough to provide hot water for a medium sized house. However, it is important to remember that it needs a venting hole opened above the unit, for the exhaust gasses of course.
Read More: Takagi T-KJr2-IN-LP
Gas vs Electric Tankless Water Heater
The first thing you should know is the demands for hot water for your household. In this modern day and age, people almost always decide to go with the tankless water heater, solely because of the on-demand hot water whenever it is needed. The lifestyles of people around the world are getting faster paced by the day, and waiting for the tank to heat up the current batch of water is not an option.
Wait time, electricity and water waste, plus the complicated maintenance is not worth the price. If you are eager to find out more about the differences between the tank and tankless water heaters, feel free to jump over to our detailed tankless electric water heater buying guide that analyzes this topic more thoroughly.
Now, the question is: should you get an electric or a gas-powered water heater for your home? The differences seem minuscule on the first glance, but there are intricate parts of the story, which make a huge difference in the long run.
First off, let`s talk about the main difference: the power source. As the name suggests, electric water heaters use electricity as the main (and only) source of energy to instantly heat the water you demand. Gas units, however, can be divided into types (more about that in the next section), and use gas as the main source of fuel, with the electricity needed only for the pilot light, and optional electronics some manufacturers put in.
To put things into clear perspective: when installing an electric tankless water heating unit, you have to map out, and sometimes reconfigure, your wiring and electrical installations in the whole house. These heaters tend to require a lot of electricity at certain times, and that affects all of the other appliances you are using. Sometimes, even a change of circuit breakers is in order, but in a modern home that is rarely the case. Here`s an expert quickly summarizing the difference in a YouTube video.
On the other hand, installing a gas-powered, combustion type, tankless water heater model requires a stable gas line, or in the cases of propane types, a well-equipped propane tank, usually located in the backyard, underground. However, gas water heaters need just one simple power outlet to enable the pilot light to function properly (and additional electronics onboard).
When it comes to price ranges and variations, it is true that gas-powered water heating units are somewhat more expensive to purchase. They can also seem a bit bulkier because of the extra chamber reserved for gas combustion. One important thing to keep in mind is the necessity of an exhaust vent for the waste gases left over after the combustion process. So, to put it shortly, gas water heaters are more expensive, in the beginning.
The reason we say `in the beginning` is quite logical, and a matter of facts. In the long run, paying for gas to substantiate the heating process is way more affordable than paying for the electricity in the case of electric water heaters. Even though electric water heaters may provide ideal solutions to some, with them being easier to install and requiring no gas line or propane tanks, we must keep in mind that these types of heating systems are being built in to stay.
If we want to compare the factor of maintenance, we would say that it is a tie matchup. Electric water heaters require tending to the electric infrastructure of the whole house and optimizing it in order for the system to work as intended. And, while the gas-powered water heating models require no special treatments of electric wiring, they need to be installed with utmost precision. Whenever we work with gas lines, and gas in general, every valve needs to be properly installed and checked.
Last, but not least, the difference in warranty policies are always present. Gas water heating units are usually covered by warranty policies for a longer period of time, and generally last longer, being that there is a minimum risk of breaks, due to most of its technology being analog. Electric water heaters are slightly more prone to stops, but this difference is quite small.
All in all, when it comes to the rivalry between electric and gas tankless water heaters, there is no straight answer. If we look at the pros and cons of a tankless gas water heater, it depends. Gas ones last longer, and generally have bigger GPM/LPM and BTU rating, but require another source of fuel, and slightly more complicated installation. Although, homeowners who decide to retrofit a tankless heating unit usually decide to go with a gas one, because, as we said multiple times, in the long run, it’s cheaper and more efficient.
Tankless Gas Water Heater Types
In the section above, we mentioned that tankless gas water heating units can be divided into 2 groups: natural gas and propane. The architecture and working mechanisms behind both of these tankless gas water heater types are practically the same, but slight differences occur, and in this case, they are mostly a matter of logistics.
Deciding between natural gas and propane depends on several factors:
- The availability of solid natural gas lines
- The possibility of switching from one source to another (usually propane to natural gas) during retrofitting
- Price of wanted fuel source
Most commonly, people who are switching from a tank to tankless water heater decided to go with natural gas if possible, being that it is usually available in urban areas. But, sometimes there is not a gas line, or the infrastructure is way too complex/old to adapt. In such cases, propane can be a more viable option.
1. Natural Gas Tankless Water Heaters
If you decided to go with the option of a natural gas tankless water heater for your home, you must check if your house meets the requirements. First of all, what every manufacturer insists on, is an adequately regulated, properly installed and serviced gas line. This may seem logical to you, but sometimes, due to gas line irregularities, manufacturers decide that the warranty policies on parts and maintenance are void.
Essentially, this option would be the most cost efficient in the long run. Natural gas is usually available all over the world, in a majority of towns and cities. You can also decide to retrofit one of these models onto your existing infrastructure. As long as the gas lines for a gas tankless water heater are up to code, there are no worries for you. And let us not forget the fact that natural gas is being refined better and better by the day. This means that you will not only be opting for an eco-friendly version but a cost-efficient one. Additionally, the caloric value of natural gas is also getting higher, meaning that your heater will be able to produce more heat with the same volume of natural gas.
Last, but not least, manufacturers of these machines often connect with the natural gas supplier in towns and cities and then let the gas companies help out with the installation, or even picking a unit sometimes.
2. Propane Tankless Water Heaters
The other option besides natural gas is, of course, propane. This type of tankless water heater also proved to be a great addition to the household and doesn`t lack in performance when compared to the natural gas ones. Both types do an exceptional job and can be used as a water heating solution for the whole house.
The main difference between the two is simply the presence or the absence of the gas line. If there is no gas line available to your home, and you want a gas-powered tankless water heating unit, propane is a better and more efficient solution.
Homeowners often decide to go with this option if they have a propane tank available for the household already. This propane tank is usually underground and is used to power ovens, stoves, and sometimes central heating units.
So, if you live in an area that does not have gas lines, or you have a propane tank installed in the ground somewhere in your yard, then a propane tankless water heater is just for you. Even with retrofitting and getting rid of the old tank water heater, people decide to stick with their already installed underground propane reservoirs (because getting rid of it is costly and often exhausting).
How Does a Gas Tankless Water Heater Work?
In order to adequately explain how gas tankless water heaters operate, it would be best to take a trip through the machine and through the pipes. In its core, this is a high capacity, fast temperature rising, long-lasting boiler. But, being that things are never as simple as they seem, we should talk about this heating process, and make everything clearer and easier to understand.
So, when you are in need of hot water and open a tap/faucet, cold water (through the standard plumbing infrastructure) goes inside the heater unit. The electronic module gives the signal to the burner module, using flow sensors, informing it that the flow has started and the hot water demand is on.
While the water is flowing towards the heat exchanging chamber, the computer automatically ignites the burner, and the combustion of natural gas (or propane) begins. The burner system with the burner chamber is positioned underneath the heat exchanging pipe system. At the same time, the electronic system controls the gas valve and the amount of gas getting into the burning process.
Under the burning chamber, in most cases, there is some sort of a fan to help the speed up the burning process. The whole burning chamber is tightly sealed in order to diminish heat loss and maximize efficiency. One of the main differences between the gas and the electric tankless water heaters is that gas water heaters use thermodynamics more efficiently. The whole setup from the bottom to the top is placed in such a way that the tendency of heat to rise is utilized to the fullest, thus using the gas in a most efficient way.
The heat exchanging chamber is more or less similar throughout all of the electric and gas models. Basically, it is a system of pipes coiled together in a way to maximize the contact surface with the heat the gas produces. After the heating of cold-water finishes, the pipes lead it past another sensor and out of the heater, directly to your tap. Here is a short summary, with an infographic in the end.
Nowadays, ever-progressing technology enables electronics inside these units to control everything automatically. All you need to do is set it up (using the instruction manual provided with the model you got) and set up the temperature you want your hot water to run at. Now, these electronic modules are essentially micro processing computers which regulate all the valves and the whole process that gas needs to go through. In short, everything is automated, from cold water getting in, gas igniting and making temperature rise, to hot tap water.
It is important to remember that gas tankless water heating units can often sustain the whole household, while the electric ones are usually restricted by the power they draw from the circuitry and wiring. Also, these types of units are well-suited to exert greater results in colder areas, because extra heating doesn`t require extra electricity. The process stays the same and doesn`t require the machine to be turned off during colder weather.
Gas Tankless Water Heater Buying Guide
Getting a gas tankless water heater is an important investment. As mentioned above, the refining process of natural gas today has really advanced, natural gas and propane are often considered eco-friendlier than using less efficient methods. In the next few sections, we will go through core things that you need to know about gas tankless water heaters. We will talk about things like size, gas line info, warranty policies, and, of course, how climate and elements should be factored in this whole equation.
Some things are more important, yes, but, when it comes to gas units, every little intricate detail can be helpful in making a solid decision.
1. Size
Let us start from the most basic part: size. As you might have already concluded from are reviews, gas tankless water heaters come in various sizes. Size roughly translates to flow when it comes to water heaters. Bigger size means more GPM/LPM can be exerted at wanted times. Gas powered units are known to pack more power (GPM/LPM) than their electric counterparts. To simplify things, we can easily divide sizes into 2 main groups: point-of-use and whole-house units.
As the name suggests, point-of-use tankless water heaters are meant to be installed in the vicinity of the fixtures that it will provide with hot water. This often means that point-of-use models are somewhat more compact and are made to fit into more common rooms of the household. These units often cover up to three taps/showers/fixtures and consume less gas overall. Their GPM/LPM is significantly lower than the whole-house ones, but the price follows. This type of water heater is recommended for smaller houses, and propane ones can be even installed into recreational vehicles.
On the other side of the coin, we have whole-house gas tankless water heaters. As the name suggests these units are made to withstand the challenge of supplying the whole household with hot water at any time. This is achieved through size. These units are bigger, more robust, and all in all heavier. But, the payoff is clearly visible right at the start. Whole-house units can be built inside or outside the house, and are more resistant to the elements and bad weather in general. Although they are more expensive, whole-house gas units are recommended for bigger houses, and larger families altogether.
2. Gas Line
One of the most important factors you should have in check is the gas line. In order for your gas tankless water heating unit to work as intended, the gas infrastructure has to be as immaculate as possible before the installation. Let`s go through several factors you should keep in mind if you want to properly choose, and adequately install the gas tankless heater of your choice.
If you are installing the new heater into a new house, ideally you will have a stable natural gas collection. In this case, a whole-house outside unit is recommended, because it will be able to sustain every need, and will not require storing space inside the house, nor an exhaust pipe (more about it later).
But often that is not the case. Only 15% of gas tankless water heaters are installed on new houses, with the rest being a retrofitting procedure. In the case of retrofitting a gas tankless heater, size plays a role, but gas availability is the most important. We must never forget that natural gas and propane are extremely flammable, thus the infrastructure must be perfectly incorporated.
If there is a public gas line, opting in for a natural gas type is the most logical option for a new home. But, sometimes you want to switch from a propane system to natural gas. This is one of the most expensive options. The main reason for this is getting rid of the underground propane tank. The excavation is usually really difficult to perform, and it comes at a hefty price. So, if you have a propane tank and a stable line already prepared, getting a new propane gas tankless water heating system is a better option. Plus, the retrofitting is less stressful if you stick to propane.
All in all, sometimes fitting a new system in an already built home is a better option, especially in the case of propane as the main fuel source.
3. Warranty
When it comes to warranty policies the manufacturers of gas tankless water heaters offer, the same rule applies for almost all models. Usually, the warranty policies are split into 3 parts and those clauses are covered as follows:
- Labor coverage: it is the shortest form of coverage and it is usually 1-3 years
- Parts coverage: this is the part of the policy that makes the manufacturer promise to replace broken parts. This part usually goes on for 5-7 years
- Working breaks coverage: the longest part covering from 7 years to lifetime warranty. It accounts for everything else (like breaks) and the manufacturers require a professional to check and verify that the installation was executed properly
4. Climate
The last, but certainly not least topic we need to touch on is the climate. Now, not to be taken literally, by the climate we mean weather conditions AND the location of your home. Weather conditions and the elements are less important when it comes to gas tankless water heaters. These units are even ok to be installed on the outside of the house. However, if you live in a harsh, low-temperature part of the world, make sure to insulate and secure your valves, propane tank or natural gas ones. They tend to freeze in extreme freezing temperatures. But, if every valve works as it should, you do not have to worry about it.
The other factor, which is far more important for gas heaters is the quality of gas you are getting. This info can be checked up with your local government. If you live in the area where the gas of lower calorie value is provided, keep in mind that more gas will be needed. In this case, considering a larger unit is a logical way to go. The info about the quality of the gas you are getting is easily obtainable, and once you do it, a factor that out as we recommended.
Of course, location also dictates the temperature of groundwater. Living in a continental or sub-tropical region means that a smaller unit is needed. By the same rule, colder regions require a larger unit, with better (higher) GPM/LPM flow. Here is a visual example of groundwater variations and its effect on unit size.
How to Install a Gas Tankless Water Heater
When it comes to the installation of a gas tankless water heater, it is important to follow instructions provided by the manufacturer in order to keep the warranty policy and keep everything safe, of course. The installation process of a gas tankless water heater can be divided into 3 phases, representing 3 types of circulation: gas setup, water pipe setup and exhaust setup.
1. Phase: Gas setup
Before you start installing, call your local gas provider to see if the gas line is up to code, and it can support a gas tankless water heater. The answer is almost always `yes`, but makes sure to do it, because sometimes they will provide special information if there is any. After you made sure that everything is up to code from the side of the gas provider, you can start the installation:
- Turn off the gas pipe before installation
- On the house end, and under the heater, install a gas supply shut off valve for safety and maintenance reasons
- Install a union connector for service purposes, under the heater shut off valve
- If it is required by code, install a sediment trap
- Check all connections and joints for leaks
2. Phase: Water Pipes
This is a more standard part of the installation, but it needs to be done thoroughly in order to get the most out of your water heating unit:
- Install the cold-water inlet connection
- Get a check valve and install it just beneath the heater. It will make sure that there is no backflow
- Install a union on the inlet and a shut off valve
The process is similar to the outlet water pipes, and it is pretty straightforward, but with a single exception. Make sure to install a pressure release valve on the outlet part.
3. Phase: Exhaust
With natural gas or propane being the fuel for the gas tankless water heating unit, there will be exhaust gases. The rule is simple: make sure to cut a hole above the unit and provide a pipe to the outside. This step is unnecessary if you are installing an outdoor type heater. The exhaust type can be connected to a chimney system, but it is not recommended by the manufacturers. So, it would be best to install a separate exhaust hole for the gasses.
And, in case you get a condensing type tankless water heater, make sure to provide a channel for the condensed water. Always use a heat-resistant plastic tube to get rid of the condensed water. There should not be a lot of water, but the dripping on the floor should be prevented. In case you want to make sure you are doing everything right, watch a professional go through some general tips.
Maintenance of Gas Tankless Water Heaters
Maintaining your gas tankless water heater is an important action that should be done annually. Some manufacturers recommend doing it every 6 months, and some say that once every 2 years is enough. If you want to determine which group you belong to, consider the quality of water in your area. If the water is full of minerals and is harder than the rule would be to service your unit every 6 months. We will split the cleaning process into 2 smaller processes: drain cleaning and gas check-up.
Now, the safety valves and shut off valves come in handy. First of all, shut down the unit via a control module, or if there isn`t any, unplug it from the wall socket. Secure the gas line by shutting it off at the security valve you installed, and disconnect the inlet and outlet water pipes. If the piping is tightly made, you can disconnect the union connectors, and this way secure a better reach.
By performing these actions, you secured the water flow, and now you can pump in the white vinegar for about 45-60 minutes in order to get rid of all sedimentation and minerals. This process should be enough to clean the parts that are in contact with the water. And, in case there is a pre-filter, here is the easiest way to find it and quickly learn/replace it.
After the drain cleaning comes the most important part: gas checkup. By this, we are going to secure several things: pilot light and the ignition module, gas line, and exhaust vents. When it comes to gas line checkups, you can consult your gas provider and ask them if anything (like pressure or calorie value) changed since you installed the heater in the first place. If anything changed from their side, they will give you adequate advice on how and what to change. This usually never happens.
Now, regarding the pilot light and circuitry checkups, most of the units have a checkup program built into the units onboard computing module. Check the user manual and run the diagnostic program. The analysis should tell you if the pilot light needs change or not. This process is pretty much automated and will indicate how to solve potential problems via a screen or indicator lights.
One very important process you should go through every time you are servicing your gas tankless water heater is the checking of gas pipes. Fortunately, these pipes are quite easy to check. The smell should be the first indicator that there are leaks. However, go through every soldered/welded angle and check for leaks. If you find any, replace the pipe and you will be fine. It is also possible to fix your gas tankless water heater after a flood.
Lastly, check the plastic tube for condensed water and make sure that it is not clogged or that it is not bent in any way that stops the flow. When you finish the cleaning and checking on the pipes, you can go the extra mile and clean the gas exhaust pipe, thus making sure that there isn’t anything stuck inside, being that it is the widest, outside facing pipe.
FAQ About Gas Tankless Water Heaters
1. How to decide between natural gas and propane tankless gas water heater?
This is one of the most common questions asked. All around the world natural gas is a preferable option. It is almost always cheaper as a resource and the regulations are governed by the city/town gas providers, which are helpful. However, sometimes natural gas isn`t available, and propane is a better option. Also, if you already have a propane tank installed for your household, switching to natural gas can be costly, so sticking to a solid propane unit is a great choice.
2. How dangerous is having a gas tankless water heater installed?
Whenever there is a gas installation (natural gas or propane), it is of utmost importance to triple check every pipe, every connector and the circuitry around the heating unit. But, the manufacturers made sure that these devices are safe to use, and installed safety systems that will halt any action, and inform you that a problem needs to be addressed. All in all, these gas-powered units are safe to use as long as they are properly operated, so no worries there.
3. What can I do to further increase savings using this type of heater?
It is absolutely true that a gas-powered tankless water heating unit will save you a fortune in the long run. But some small adaptations can be made to further increase money savings. From simple things like reducing hot water usage and lowering the heating temperature of the unit, to properly insulating the water pipes and regular maintenance. If the unit is not properly cleaned it will not do as good of a job and will consume more gas for less heating. So, maintaining and cleaning the cleaner is a good way to save money.
4. Should I install the gas tankless water heater by myself?
The short answer is: yes. If you follow the instructions provided by the manufacturer and our tips and tricks on how to approach the installation, you should not encounter any problems. Also, it is important to remember that most of the manufacturers are affiliated with gas providing companies, and they train licensed maintenance specialist. So, if you have issues with the installation, stop and call your local gas provider, and in the majority of cases, they will provide help. Just make sure you do not damage any part of the equipment because of the warranty.
Tankless Gas Water Heater Comparison Chart
| Product | Size (inches) | Weight (pounds) | GPM | Warranty for parts (years) |
|---|---|---|---|---|
| Takagi T-KJr2_IN-NG | 6.7 x 13.8 x 20.3 | 37 | 6.6 | 5 |
| Rinnai RUC98iN Ultra Series | 10 x 18.5 x 26 | 82 | 9.8 | 5 |
| Rheem RTG-84XLN 8.4 GPM | 14 x 10 x 26 | 54 | 8.4 | 5 |
| Eccotemp i12-LP | 15 x 24 x 4 | 29 | 3 | 2 |
| Aquah Indoor | 16.5 x 8 x 27 | 30 | 4.3 | 2 |
| Takagi T-KJr2-OS-NG | 6.7 x 13.8 x 20.5 | 38 | 6.6 | 5 |
| Rinnai V65EN 6.6 GPM | 13.8 x 6.8 x 20.9 | 47.5 | 6.6 | 5 |
| Eccotemp L10 | 15 x 6.5 x 35 | 27 | 2.6 | 1 |
| Rinnai V65IN 6.6 GPM | 13.9 x 8.8 x 23.6 | 32 | 6.6 | 5 |
| Camp Chef Triton 10L | 31 x 16 x 9.2 | 26.5 | 2.6 | 1 |
| Rinnai V65IP 6.6 GPM | 13.9 x 8.8 x 23.6 | 49.6 | 6.6 | 5 |
| Takagi T-KJr2-IN-LP | 6.7 x 13.8 x 20.3 | 38 | 6.6 | 5 |
Wrap Up
There you have it, detailed insight into the world of gas-powered tankless water heaters. There is a lot of info to process, and a lot to think about. Take your time and decide which is the best tankless gas water heater for your household. There is plenty of choices, the competition is fierce, but now you are armed with facts and knowledge, and the decision should come more easily.
We hope that our tankless gas water heater reviews helped as well. We suggest going through them and pick the right unit to install in a new house or to retrofit into an existing residence. Just make sure to maintain the unit as proposed by the manufacturer, and do it regularly.
In case you have additional questions, feel free to ask in the comment section below, and we will gladly provide answers and help you out.
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