Tankless gas water heaters last longer than tanked heaters, provide hot water whenever you want it, for as long as you want it, and will save you a nice chunk of change every month. Most reviewers report 30-40% reductions in their gas bills! These devices are a worthwhile investment based on their convenience alone. Their financial savings and environmental friendliness only sweeten the bargain!
Compared to electric models, gas-powered units have better cold-weather performance and average lower fuel costs over time. They’re also more reliable over the long term.
To get the full range of benefits, it’s super important to select the right water heater for your household’s specific needs. The range of options on the market is vast and it’s all too easy to get an inadequate unit for your needs, or to overpay for one you won’t fully make use of. This equipment can be costly, especially because gas units require you to install proper ventilation ports and fuel hookups. This guide will help you get it right the first time.
We’ve got the know-how, and have come up with a list of high-quality options available today. We’ve sorted them into easy categories: top sellers, highest overall quality, and the best value buys.
Best Gas Tankless Water Heater Reviews
- Rheem RTGH-95DVLN: for those who want limitless supply
- EcoTemp FVI -12-LP: for those with low demand, and those looking for maximum savings
- Takagi TK JR2 NG: for the average household
1. Rheem RTGH-95DVLN 9.5 GPM Indoor Direct Vent Tankless Natural Gas Water Heater
This is one amazing residential tankless water heater. Someone could take two showers, run the dishwasher, hand wash a pan, and do a load of laundry––all at the same time! It is a condensing unit, which is the most energy-efficient option. All its amazingness comes with a cost that will make it prohibitive for a lot of folks, but if you have a large demand for hot water, this is a great value. It’s easy to install, works quickly and quietly, and many buyers say it puts out just as much flow as their old tanked heaters.
With a very high flow rate of 9.5 gallons per minute (GPM), this Rheem could heat three high-flow showers at once. You truly will never run out of hot water with this one, even at times of peak usage. With this Rheem, the coldest climates will never cause a drop in pressure or temperature, and you do not have to compromise on functionality, ever.
Also, as a condensing unit, this Rheem extracts heat from exhaust gasses, which makes it more energy-efficient and thus cheaper long-term than non-condensing models. Efficiency ranges from 90% to up to 98% under ideal conditions; non-condensing heaters max out around 80% efficient in ideal conditions. And because the exhaust gasses aren’t as hot upon their exit, you can use cheaper venting materials in the installation phase.
The big drawback to this unit is the price tag. Smaller households (1-4 people) do not need something this powerful, and can probably get away with a cheaper choice.
Some reviewers also noted trouble getting their units serviced, because like every tankless water heater, the warranty only covers parts and not labor.
This is a great tankless water heater for big households or small households with high demand. The Rheem is not intimidated by even the coldest of climates. If price is no object, this is the unit you want, without question.
Folks in warmer climates or in small households may want to look at our other picks, but in terms of purely reliable functionality, this should treat you nicely.
2. Ecotemp FVI-12-LP High Capacity Propane Tankless Water Heater
This Ecotemp is a popular and much more affordable choice than the Rheem. It’s also one of the most energy-efficient on the market. It’s not a great choice for supplying multiple fixtures or appliances at once, but the Ecotemp is a great option for people who live alone, or for households where hot water usage is staggered.
The price is by far the most appealing part of this tankless heater. It’s hard to argue with how much cheaper it is relative to other heaters. It’s designed to use even lower amounts of fuel than other gas units, too. Since it is a smaller size, you might also be able to attach it to the gas line input from your old tanked unit, which saves you money on installation.
Even though it’s budget-priced and compact, you’ll hardly be roughing it. Thanks to an output rate of 3.5 GPM, one hot water task at a time should be no problem. That’s more than enough to run a shower, and if you’re using a low-flow fixture, it’ll perform fine in winter months.
It’s effective for its size. Previous buyers say it has a very short lag time, and once it’s on, it provides a continuous supply of hot water with no gaps or struggles.
While two low-flow (1.5 GPM) showerheads could theoretically run off this unit at the same time, that’s probably pushing it. You may be able to get away with using a sink while someone’s in the shower, but this unit is really better suited for people who won’t have overlapping hot water usage. Even one shower in the coldest weeks of winter might be an issue if you’re not using a low-flow showerhead. With a fixture that runs closer to 3-3.5 GPM, run the risk of having lower water pressure in order for the water heater to reach the appropriate temp.
Several reviewers complained about poor customer service when the unit failed. Overall, EcoTemp doesn’t have a great reputation as a company. Their products are generally good, but their service isn’t exactly stellar.
This is a great choice for smaller households and could even work okay in medium-sized households (3-5 people) in warm climates, provided you get used to taking one shower at a time. If you are already environmentally conscious and have low-flow showerheads, this heater might be a perfect budget option. Larger homes and households with higher hot water demand should look at our other choices, though.
3. Takagi T-KJr2-IN-NG Indoor Tankless Water Heater, Natural Gas
The Takagi is an extremely well-reviewed water heater that should be perfect for most households of five or fewer people. While it’s not as crazy-powerful as the Rheem above, two showers at once shouldn’t be a problem. If you have at least one low-flow showerhead, you may even be able to get away with a third fixture. This one is a great price for all of its capabilities! We think this is an excellent, convenient choice for small to medium households.
Even though it’s close to the same price as the Ecotemp, The Takagi comes with a higher hot water capacity. In fact, it’s three whole gallons per minute higher, at 6.6 GPM!
This Takagi will have no trouble in cold climates, and will satisfy demand for all medium-use households. If you’re using low-flow fixtures, you should have no problems running two showers at once, even in colder weather. In warmer spots, you may even be able to run three different fixtures, as long as they’re all rated as low-flow.
The Takagi is one of the most well-reviewed units on the market right now! In fact, the only complaints we could find about this model had to do with the installation costs, which are about on par with other gas units. As always, we recommend doing your research on the installation costs up front, so that you’re prepared to make a sound budget call on which unit you can afford.
It’s very user-friendly. There is a digital remote for precise control available, and reviewers say it’s worth the slight price increase. Previous buyers also complimented the easy, quick installation process. You’ll just need to hook it up to gas and water lines, then plug it in. Easy as pie! They said it works perfectly from the first use.
It’s more reliable than the Ecotemp over the long term.
One reviewer described noticing slightly cooler temperatures during simultaneous showers, but had no problems with one shower at a time. Since it’s an isolated complaint and they didn’t mention their fixtures’ usage rates, we’re going to assume they were running two normal-flow showerheads, which would be pushing the Takagi to its limit. Remember that you’ll always have better results with low-flow showerheads. The top tier of hot water demand households (more than two bathrooms, homes with gigantic square footage, or folks who don’t want to have to meter hot water usage) might want to go for a bigger unit.
The Takagi is big enough to satiate the hot water desires of most households, and not so expensive as to be out of range for the average consumer. A good choice for most mid- to high-demand living spaces. It’s a also a great choice for smaller homes in colder climates.
Best Retrofit Option-Marey Power Gas 10L 3.1 GPM Propane Gas Digital Panel Tankless Water Heater
The size of the gas input on most water heaters with a tank is ½”, but most tankless water heaters are ¾” or even 1”, so there is an added cost of installing the correct size piping. (Exact costs vary depending on your exact situation; consult with a qualified technician for specific information). This water heater is ready to use right away, because it only needs ½” pipe. This is a great option if you want a water heater that is easier and cheaper to install.
The main advantage of the Marey is price, including the lower installation cost. This is the cheapest solid option on the market right now–even cheaper than the Ecotemp.
At 3.1 GPM, this heater has a limited output. Simultaneous showers are out of the question, and people in cold water climates will only have good results using low-flow fixtures.
A cost-effective option for environmentally conscious households with low-flow showerheads and small households in general (i.e., apartments, efficiencies). This one is not ideal for houses of any reasonable size (i.e., more than 2 bedrooms, more than 1 bath).
The promise of tankless gas water heaters (unlimited hot water, and substantial long-term energy savings)! will only ring true for you if you buy a unit that’s appropriate for your needs. With so many options to choose from, it’s a tricky thing to find your ideal balance between price and functionality.
A hugely important factor to consider is household size. Generally speaking, an apartment shouldn’t need the same gallons per minute (GPM) output from its water heater as a five-bedroom house. If you’re only running one shower or hot water-driven appliance at one time, there’s no reason to spend lots more money for something that’s designed to run several.
That brings us back to price. A smaller household or apartment can get its needs met with a much cheaper unit. Likewise, people who own larger homes with multiple bathrooms should plan on spending substantially more at the checkout.
To figure out how much you need to spend, you need to figure out how much hot water you need at any one time. This is a matter of finding your GPM (gallons per minute) usage. Look at the GPM rating on your shower head to find out how much water it uses.
The shower is by far the appliance with the largest hot water demand. The standard shower ranges from 2.5-3 GPM, while low-flow showerheads typically output 1.5 GPM. Do the same for your sinks. It’s also a good idea to check your appliances like a dishwasher or a washing machine to see how much they use.
Then, think about how many of those feeds you use at once, and how much that total GPM would be. For instance, if you live alone but like to run a load of laundry while you shower, you will want to add the washing machine to the shower head to get your total. If you live alone, and don’t run any other appliances while you’re in the shower, your total will simply be the flow rate on your shower head.
We always recommend rounding up by about 50% of your total requirements, in order to give yourself an appropriate margin of error.
In colder climates where your unit will have to work harder to heat your water, you should round up by as much as 75-100%. That’s because most models are tested at average input temperatures, which don’t apply in some far northern or high altitude regions.
Climate determines how cold incoming water is, which in turn determines the effectiveness of your hot water heater. The GPM output that companies list is the maximum possible output of water that unit can heat. You do not want to underestimate demand, especially in colder climates. Tropical climates like Florida can get away with much less powerful units, even in large households, because the heaters themselves have to do so much less work. Conversely, an apartment in Chicago should probably invest in a more powerful unit.
The final thing to consider is installation costs: specifically, the amount you’ll have to pay for venting construction and retrofitting your gas line. Tankless gas water heaters have a higher upfront cost than their electric counterparts. That’s because indoor units must be vented, and outdoor units cost even more to be weatherproofed.
Even if you’ve already got a gas line going into your house, you’ll probably need to make some slight modifications. Most water heaters with tanks use a ½” gas line, but most tankless heaters require a larger gas input, ¾” at least.
In short, installation isn’t usually as simple as just plugging and playing. It’s always worth consulting a qualified plumber to determine the full cost of retrofitting your house for a tankless gas heater.
All that said, though, natural gas is significantly cheaper than electricity, and if you pick the right unit that lasts, you will save money every month until it pays for itself. Most buyers say that their machines paid for themselves within the first 1.5-2 years!
Any of these units is a reliable, effective choice.They will all save you money on your utility bills and, should they last long enough, will pay for themselves in the process. Choosing your ideal one depends on your specific situation.
Do you live alone or have a single-bathroom apartment? The Eccotemp (option #2) or the Marey (option #4) might be perfect. Do you have a big house, a ton of people using hot water, live in a frigid climate, and/or just want hot water peace of mind? The Rheem (option #1) is right for you. In between those extremes, the Takagi (option #3) is a terrific choice.
Welcome to the world of on demand gas water heaters!
Electricity might be more expensive than natural gas in the long run, but many people prefer electric heaters because the upfront cost tends to be lower, both in the cost of the unit and in the installation. See our overall picks, read our Best Tankless Water Heater Reviews 2017!