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
“for the modestly competent mechanically inclined”
The EZ Ultra HE is an extremely affordable gas water heater with very high reviews. We think it’s the best bet in the gas category for someone on a budget in a small to medium-size household with fairly low demand for hot water.
It can supply you with with 2-3 fixtures at once in a warm climate, so it’s practical for an average household in most of the country. It’ll also provide ample hot water for apartments and smaller homes in cold climates.
You’ll need to come up with your own GPM requirements, but if you’re using low-flow fixtures and efficient appliances, you should easily be able to do two things at once with this, even in a cold climate. Some folks in warmer spots may even be able to get a third running without issues.
In short, if you’re on a tighter budget and can make do with using 4.4 GPM or less, this is a fantastic little workhorse.
It’s a great value. This isn’t the cheapest gas tankless water heater out there, but we think it’s the cheapest that’s worth your money.
This EZ Tankless will have no trouble in cold climates, unlike many other inexpensive gas units. This unit is an excellent choice for those living in homes with 1-2 baths.
It is also quiet at about 61 decibels, which is equivalent to the normal human voice.
“We have a 2 bath/shower home and no reduction at all in water pressure was noted.”
This unit is not the hottest selling item on the market as it is a lesser known brand, but it does have the highest ratings, with 5 star averages on several review sites. 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.
“an extremely compact water heater, even for a tankless unit!”
If you don’t use low-flow shower heads or efficient appliances, you won’t get more than 2 things going at once with this unit. We always recommend making your household plumbing more efficient before moving to a tankless system, but if that’s not something you’re prepared to do, you should opt for one of our larger picks.
If you have a medium-sized household in a cold spot, the Rinnai will give you more wiggle room when winter rolls along.
Likewise, the Rinnai will safely run three things at once (as long as they’re only 2-2.5 GPM each). If you want that kind of capacity, you’ll need to spend a bit more.
Customers cited that the unit was reasonably easy to install, but it did require a lot of pre-planning. You should have the setup done by a professional, if you want the warranty to cover you (and who wouldn’t?). The difference is that you shouldn’t have to pay for as much labor time with this as with some other units we’ve come across.
The EZ Ultra HE also comes in a propane version.
The price and specs are the same, but could be an option for a household without a natural gas line.
“a good choice for the average household.”
Rinnai’s V75-IN is our top midrange recommendation for a gas tankless water heater. It’s rated at up to 7.5 GPM, and we think it’s a good choice for the average household.
You can easily run two or three things at once on this (provided you’re using low-flow plumbing fixtures and efficient appliances), depending on where you are. It’s part of Rinnai’s High Efficiency series, and has a superb .82 energy factor.
It’s a nice balance between the massive output and massive price tag of the Rheem, and the affordability of the Takagi.
With an output of up to 7.5 GPM, the Rinnai is ideal for the average household, in any climate. You can easily have two showers running at once on this one, and still have some spare hot water for a sink. Or, you could run a load of laundry, take a shower, and have someone else do dishes at the same time.
“ideal for the average household, in any climate.”
Your actual results will depend on the efficiency of your fixtures and appliances, as well as your inlet temperature. Still, this is a good choice for the average small to medium-sized household where several things are often running at once.
It’s very efficient, as we’ve already mentioned, and it has low emissions ratings to boot. The Rinnai is SCAQMD-approved. This is a lot more environmentally-friendly than other midrange gas units.
It’s certified for mobile and prefab homes, too! A lot of tankless models aren’t, which is a shame because they’re ideal for tighter living spaces.
“You wouldn’t feel bad leaving this exposed”
Like the best tankless water heaters, the Rinnai is neat and compact: 14” x 9” x 23”. We think it looks good, too. You wouldn’t feel bad leaving this exposed, especially if you can install it next to another white appliance (such as a washing machine).
We think the controls are just right on this one. Some models these days are annoyingly “tech-y” and draw more attention than you want to a water heater. The Rinnai has an unobtrusive display, but still gives you easy access to everything you need.
You can choose settings between 98-140 degrees. There’s a temperature lock to prevent any accidental changes to the temperature settings and limit.
Rinnai units have a great track record for long-term performance. This one has as solid a reputation as you’d expect from the brands. We haven’t discovered any long-term issues or design flaws.
You’re covered by warranty for 10 years on the heat exchanger, 1 year on labor, and 5 years on parts. Follow the links in this review to purchase one with extended warranty coverage, if you like to add that.
One reason we prefer this to other midsize gas units is the smart safety system built in. It’s a well-designed way to keep things sound for years. Scale detection prevents any damage to the unit and automatically shuts things off if you haven’t followed the cleaning schedule, or if your water composition needs more frequent descaling.
There’s also built-in leak detection, which is a fantastic feature we wish more companies would roll out. If one of these should somehow spring a leak, it’ll sense it and shut itself off to prevent water damage. That’s the worst case scenario when water heaters go south, so we’re big fans of this feature!
Like any midrange tankless model, it’s a bit slower to respond than a small model like the EZ Ultra HE. It’s still only about a 30-second wait for most people, but that’s something to consider if you’re deciding between the EZ Ultra HE and the Rinnai. The EZ Ultra HEwill get you your water slightly faster, but the Rinnai has a higher capacity once it’s up and running.
You’ll need to get a direct-venting kit. This doesn’t come with anything but the heater unit.
This is our recommendation to the average home. That’s a pretty vague term, so you should get some hard numbers to use as a benchmark for your water requirement. In general, this ought to be suitable for the typical family in a small to medium-sized home. Medium and large homes with heavy usage requirements, or medium size homes in particularly cold areas would be better off with the Rheem below.
“one beast of a tankless water heater!”
This is one beast of a 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! Not only does it have a massive output capacity, but it uses energy very sparingly. It’s a condensing unit, which is the most energy-efficient gas option on the market.
All that power and efficiency comes at a cost that will make it prohibitive for a some folks, but if you have a large demand for hot water, this is a great investment. It’s easy to install, works quickly and quietly, and can compete with any tank model in the flow department. And of course, you’ll never run out of supply!
This is a great tankless water heater for big households or small/medium households with high demand. The Rheem is not intimidated by even the coldest of climates. It’s also the ideal tankless model for folks who never want to have to think about managing their hot water usage. If price is no object, this is the unit you want, without question!
With a very high flow rate of 9.5 gallons per minute (GPM), this Rheem could heat three full-flow showers at once. You truly will never run out of hot water with this one, even at times of peak usage. It’s ideal for larger households, even 4-bedroom and larger.
“It’s ideal for larger households”
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. We’ve heard from buyers in the coldest parts of the country who have all attested to the fact that it cranks at full-bore no matter the weather.
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 is third-party certified to 94%; non-condensing heaters max out around 82% efficient, even 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! There’s a built-in electric blower to help out with venting, too. That’s something a lot of other large models neglect to include.
As with the Rinnai and Takagi, it’s a low-NOx model. Between the low emissions and the ultra-efficient design, it’s comparable to many electric models in the eco-friendly department.
“it’s comparable to many electric models in the eco-friendly department.”
It includes a remote control in the box, so you don’t need to buy anything separately.
Many other large-capacity tankless models are fairly industrial, but this Rheem balances brute force with brains. It has lots of smart features, like the Rinnai. There are self-diagnostic controls, and maintenance codes are displayed on the panel, as well as temperature settings. You can quickly pair these units up, and they’ll work together seamlessly to heat the largest demands.
“They don’t come hardier than this!”
It’s still industrial-quality, though. The Rheem works up to 9840 feet above sea level and packs freeze protection to -30F. They don’t come hardier than this! If you’re in an extremely cold spot and need to compensate, this should be right up your alley.
As with our other recommendations, the Rheem is extremely reliable. It has a 10-year warranty on the heat exchanger, and 1 year of coverage on the parts.
The big drawback to this unit is the price tag. It’s the most expensive gas model we recommend. Be prepared to spend at least $1K for the heater, not including fittings or installation costs.
This is overkill for a lot of people. Smaller households (1-4 people) do not need something this powerful, and can very easily do with one of our less expensive options. Be sure to come up with your own GPM requirements and check your inlet temperature, to make sure you can justify buying this!
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. Now check 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 cost: 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 before you buy.
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!
All of our recommendations are reliable, efficient and rugged. They’ll all last for years of service, and they should all more than pay for themselves over time. Still, the best one for you depends on your specific needs.
The EZ Tankless is a very affordable option for people on a budget who can stand to use 2 or fewer fixtures/appliances at once. It’s all you need in a one-bathroom home, or for someone who primarily lives alone. You could also use it in a medium-sized home, as long as you don’t plan to run more than two things at a time. If you want more flexibility, go for either the Rinnai or the Rheem.
The Rinnai is the best choice for the “average” person, who wants to comfortably be able to run 2-3 things at a time, in any climate. It’s not too much bigger than the EZ Ultra HE, but gives you enough extra power to avoid budgeting your hot water usage so much. It’s a better choice than the EZ Ultra HE for smaller homes in very cold spots, and should be all a medium-sized home needs in a more temperate area. Again, check your own GPM needs!
Finally, the Rheem is the best way to go if you don’t want to worry about capacity at all. Even if you have three bathrooms, you can shower in each of them at the same time. It’s ideal for larger households, spacious homes, and folks who simply don’t like to have to budget their hot water use. Just know that it’s quite expensive, and that many people don’t actually need something this powerful.
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 !