Best Tankless Natural Gas Water Heater

Best Tankless Natural Gas Water Heater

10 minutes Last Updated: 07/05/2019

After 110+ hours of research & testing, we’re comfortable recommending the Rinnai V65IN as the best value tankless gas water. It was rated as one of our 3 highest quality units while being significantly cheaper than the other 2 (by up to $1,000). With that said, if you’re looking for the highest quality unit available (period), we recommend the Rinnai RUC98iN for its high energy factor & long term durability. We maintain these recommendations even after accounting for newer models of other brands that have been released in the first half of 2019. Read further for our findings.

 

Note: we previously recommended the Bosch C 1050 ES as a top pick, but it has since been discontinued.

Takagi T-Kjr2-IN-NG Indoor Tankless Water Heater (Natural Gas)

Takagi T-Kjr2-IN-NG Indoor Tankless Water Heater (Natural Gas)

7/10
  • Inlet and outlet constant temperature monitoring
  • Energy factor of 0.81-0.83
  • Minimum GPM to activate is .5 GPM, minimum PSI is 15
  • Max temperature is 167 Degrees F
  • 10-year heat exchanger warranty and 5-year parts warranty
  • Can require some troubleshooting and additional pieces to install to work effectively
  • Doesn’t heat consistently at lower flows (some reviewers mentioned that heating would cut out on sink faucets unless at higher flows)
  • 4-Inch category III stainless steel venting required
  • Warranties are only valid if unit was installed by a properly licensed technician
Dimensions:
6.7 x 13.8 x 20.3 inches
BTUs:
140,000
Max Flow Rate:
6.6 GPM
Color:
White
Certifications:
Energy Star

Our Review

This unit is best used for smaller apartments and small area heating applications. It is reasonably priced, energy efficient, easy to maintain and worked well for most reviewers. For some, they had to increase the size of their gas lines to make sure the unit was getting enough gas to work properly. The warranty isn’t as long and the minimum PSI is a bit higher than other options. The very high percentage of positive reviews gives this a higher rating.

Eccotemp fvi12-NG FVI-12 Tankless Water Heater (Natural Gas)

Eccotemp fvi12-NG FVI-12 Tankless Water Heater (Natural Gas)

3/10
  • Safe, efficient power ventilation
  • Easy to read digital temperature display
  • Stainless steel horizontal vent
  • Works for indoor use with a safe electronic ignition system that plugs into a standard 120v electrical outlet
  • Max PSI is 80
  • 2-year limited warranty that multiple reviewers said wasn’t supported by the company
  • Manual water heater, so have to adjust water temperature at the face of the unit
  • Best with 35-50 PSI water pressure
  • Doesn’t work well with a mixer faucet as best used for single faucet use
  • Many reviewers found it not reliable and cumbersome
  • Really just for indoor use as is dangerous at below freezing temperatures
Dimensions:
6 x 15.5 x 25 inches
BTUs:
74,000
Max Flow Rate:
3.5 GPM
Color:
White
Certifications:
UL

Our Review

This can work for a small home, cabin or apartment. It functioned well for some and is lower cost, but many had to make adjustments to make it fit their needs. A high percentage of negative reviews lead us to not recommend this unit as well as the patience and understanding required to work with it.

Eccotemp i12-LP Water Heater (Propane)

Eccotemp i12-LP Water Heater (Propane)

5/10
  • Safe, efficient power ventilation
  • Easy to read digital temperature display
  • Stainless steel horizontal vent
  • Sleek modern design with tempered glass front panel and LED display controls
  • Safe electronic ignition system
  • Fully automatic temperature controls
  • Energy saving mode and child lock technology
  • Minimum PSI of 14 and max temperature of 140 degrees F
  • Plugs into standard 110v electrical outlet
  • 2 Year Limited Warranty
  • Reviewers in colder weather have had issues
  • Some have experienced a lack of customer support
  • Exhaust pipe is a non-standard size for most
  • Requires additional purchases to work for many
  • Higher flow rate of .75 GPM required for activation
Dimensions:
15 x 24 x 4 inches
BTUs:
80,000
Max Flow Rate:
3 GPM
Color:
Black
Certifications:
UL

Our Review

This also works for smaller cabins or homes. Reviewers with cabins, trailers, or under 1,000 square foot homes and basic needs seem to get enough hot water and good value out of this product . Minimum water pressure is 14 PSI, though works best at 55-60 PSI per customer comments. This is not for heavy-duty use. Multiple reviewers say you need to purchase the valve kit as well as install a flushing unit as well.

Camplux 10L Outdoor Portable Tankless Water Heater with Digital Display (Propane)

Camplux 10L Outdoor Portable Tankless Water Heater with Digital Display (Propane)

6/10
  • Maximum 110 PSI water pressure
  • 11.5% energy saving technology
  • Eco/Full switch function
  • Flame failure device, anti-freezing protection, overheating protection to ensure safety
  • Easy to setup and install
  • Max temperature of 167 degrees F
  • Minimum water flow PSI is 3.6 and activation GPM is .528
  • Gas water heater can’t be used for drinking water
  • LED temperature readout is Celsius not Fahrenheit
  • 1 year warranty
  • Poor accessories, specifically shower head and some have complained about regulator
Dimensions:
21.6 x 12.9 x 8.3 inches
BTUs:
68,000
Max Flow Rate:
2.64 GPM
Color:
White
Certifications:
CSA approved gas regulator

Our Review

This wall mounted unit works well for camping and outdoor showers, as well as remote spaces like mountain cabins and horse stables. Ignition is via 2 D batteries so works where electricity isn’t available. It seems to be mostly used outdoor but can be adapted for indoor use as well. Many like how simple it is to install. They say it comes with everything you need, which it does technically, but many reviewers suggest to replace the factory regulator and accessories like the shower head. The rating also reduces due to the very limited 1-year warranty.

Takagi T-K4-IN-NG Indoor Tankless Water Heater (Natural Gas)

Takagi T-K4-IN-NG Indoor Tankless Water Heater (Natural Gas)

8/10
  • Exhaust and water temperature control
  • Energy factor of 0.82
  • Compact design allows it to be wall mountable
  • Works for 2-3 bathrooms and is quiet
  • Max temperature of 165 degrees F
  • Built-in freeze protection and works up to 6,000 ft elevation
  • Direct vent capability
  • PSI range: 15- 150
  • Warranty is 12 year heat exchanger and 5 year parts and 1 year labor.
  • Indoor Installation Only
  • High BTU but some customers still feel drop in heat during shower when water used elsewhere
  • Takes some time for water to heat
  • Vent type required is category III stainless steel
  • Warranties are only valid if unit was installed by a properly licensed technician
Dimensions:
8.5 x 13.8 x 20.5 inches
BTUs:
190,000
Max Flow Rate:
8.0 GPM
Color:
White
Certifications:
Energy Star

Our Review

With 2-3 bathroom capacity, this unit should work for a small to medium size house. To get the most out of it you should get it professionally installed. Warranty also requires it. It is quiet, can be mounted on a wall and has a higher maximum water pressure than other options. Only potential negative is that your specific setup might require you to purchase a stainless steel vent which adds a significant additional cost.

Rheem RTGH-95DVLN Indoor Direct Vent Tankless Water Heater (Natural Gas)

Rheem RTGH-95DVLN Indoor Direct Vent Tankless Water Heater (Natural Gas)

8/10
  • Energy factor of 0.94, very efficient!
  • Works for 3 bathroom homes and is quiet for many
  • Built-in freeze protection and high altitude compliant up to 9,840 ft elevation
  • Max temperature is 120 degrees F, though you can an upgrade up to 185 degrees F
  • Direct vent capability with two pipe vent system designed to use PVC pipe
  • Minimum activation flow rate is .40 GPM and minimum PSI is 15
  • Self-diagnostic system with digital display
  • Hot start programming to minimize fluctuation in water temperature
  • Built-in electric blower
  • Relatively low exhaust temperatures
  • Warranty is 12 years on heat exchanger, 5 years on parts, 1 year on labor
  • Indoor installation only
  • Mixed experiences with customer support, some good and some bad
  • Not as consistently quiet as other options as some reviewers mentioned it was noisy
  • Flush valves not included
  • It didn’t last more than a couple years for a few reviewers before having issues
  • Some experienced difficulty installing or had significant added installation costs
Dimensions:
18.5 x 9.8 x 27.5 inches
BTUs:
199,900
Max Flow Rate:
9.5 GPM
Color:
Silver
Certifications:
Energy Star

Our Review

A few reviewers experienced issues with a bit of noise, some breakdown after a couple years, or added installations costs. Even with that in mind, this received a very high percentage of 5 star reviews, has a very high energy factor, a warranty that competes with the best and a system that can use standard PVC pipe. A solid option for a home with 2-3 bathrooms.

Rinnai RUC98iN Ultra Series Twin Pipe Tankless Water Heater (Natural Gas)

Rinnai RUC98iN Ultra Series Twin Pipe Tankless Water Heater (Natural Gas)

9/10
  • Energy factor of 0.96 and quiet, highest max efficiency!
  • Low NOx emissions and works in a house with 3 bathrooms
  • Max temperature of 140 degrees
  • Helpful customer service for most reviewers
  • Works at higher altitudes (with some adjustments) and in colder climates
  • PSI range 50-150 and minimum activation flow rate of .40 GPM
  • Multiple safety devices including flame failure
  • Many were able to install on their own and get to work correctly
  • Direct vent system that works with concentric, PVC, and centrotherm
  • Warranty is 12 years on heat exchanger, 5 years on parts, 1 year on labor
  • Customer service will try to fix piece by piece rather than sending a new unit
  • A higher minimum PSI of 50 vs other options and recommended 60-80 PSI for optimal performance
  • Indoor use only
  • Lower max temperature than other options
Dimensions:
10 x 18.5 x 26 inches
BTUs:
199,000
Max Flow Rate:
9.8 GPM
Color:
Silver
Certifications:
Energy Star

Our Review

From reviews, this unit seems easy to install and also has an energy star rating. With the highest max energy efficiency and multiple options for the direct vent system as well as the same warranty terms, this edges out option #6. If you don’t need a higher max temperature than 140 degrees F and don’t need a lower minimum PSI than 50, this is a great option for a 3 bathroom home.

Rinnai V65IN Indoor Tankless Water Heater (Natural Gas)

Rinnai V65IN Indoor Tankless Water Heater (Natural Gas)

8/10
  • Energy factor of 0.82
  • Low NOx emissions
  • Lightweight and Compact
  • Max temperature of 140 degrees F
  • Compatible with full line of Rinnai digital controllers
  • Quiet and works very well for 1-2 bathroom homes, cabins, offices, etc.
  • One button turn off or on for long periods without use
  • PSI range 20-150 and minimum activation flow rate of .40 GPM
  • Multiple safety devices including flame failure
  • Installs easily with recommended vent kit
  • Works at 6,000 foot elevation
  • Warranty is 10 years on heat exchanger, 5 years on parts, 1 year on labor
  • Indoor use only
  • Lower max temperature than other options
  • If have cold water, won’t get more than 3.3 GPM
  • If have hard water, will need water softener with this unit
Dimensions:
13.9 x 8.8 x 23.6 inches
BTUs:
150,000
Max Flow Rate:
6.6 GPM
Color:
White
Certifications:
Energy Star

Our Review

If you have a smaller house with 1-2 bathrooms, this is worth considering. It has a lower minimum PSI and a lower cost than option #7. It also has a slightly shorter warranty, lower flow rate, and is a bit less efficient (lower energy factor). Same solid brand with a few less features, but most reviewers had very good experiences.

Eccotemp 45H-NG Outdoor Tankless Water Heater (Natural Gas or Liquid Propane)

Eccotemp 45H-NG Outdoor Tankless Water Heater (Natural Gas or Liquid Propane)

2/10
  • Outdoor installation, quiet and compact
  • No venting required
  • Easy and quick installation process
  • Comes with temperature and pressure release valve, shut-off valve for gas and ¾” NPT fittings, digital remote
  • Works for a single family home, 2-4 applications
  • Max temperature of 120 degrees F
  • Not energy star rated
  • 5 year limited warranty is shorter than some of the competition
  • Does not have an adjustable flow sensor
  • A good percentage of reviewers had inconsistent temperatures of water - too hot or cold
Dimensions:
22 x 15 x 6 inches
BTUs:
150,000
Max Flow Rate:
6.8 GPM
Color:
White
Certifications:
UL, CSA

Our Review

It’s nice that there’s no venting required, it’s easy to install, and can mount outdoors. The shorter warranty coupled with reviewers having very inconsistent water heating experiences leads us to not recommend this option. It has a high percentage of 1 star reviews. There are better options.

Vevor 18L Stainless Steel Tankless Water Heater (Propane)

Vevor 18L Stainless Steel Tankless Water Heater (Propane)

6/10
  • Easy to mount on a wall and only turns on when in use
  • Comes with a shower kit and works with up to a 2 bedroom, 1-2 bath under 2,000 square foot house, cabin, or condo
  • Both cold water and warm water can be controlled properly
  • Safe for use with protections from overheating, freezing, low water, flame failure, dry combustion, and high water pressure
  • Uses 2 size D batteries to light pilot so works well in off the grid setups without electricity
  • Max PSI is 70
  • Stainless steel prevents corrosion
  • Provides very hot water
  • Lower cost
  • No certifications
  • You will need some additional items and some reasonable handiness to install properly as some found directions not very helpful
  • Due to .5 water connection vs. standard .75 connection, some reviewers had some flow issues when needing hot water from more than one point in the house
  • 20 minute limit on heat cycles
  • For most reviewers it took a few tries to get water temperature right
  • No warranty details and reviewers have complained about a lack of customer service
Dimensions:
29.5 x 16.5 x 8.7 inches
BTUs:
Unknown
Max Flow Rate:
4.8 GPM
Color:
Stainless Steel
Certifications:
None

Our Review

Though it has a high percentage of 5 star reviews and is very low cost, we can’t give this too high a rating due to a few factors. The 20 minute limit on heat cycles and adapting to .5 inch equipment is cumbersome. Per reviews the directions are not very helpful, customer service isn’t great, and there are no warranty details.

Ridgeyard 18L Tankless Water Heater (Propane)

Ridgeyard 18L Tankless Water Heater (Propane)

4/10
  • Manifold, overheat, over water pressure, and anti-freeze protection
  • Energy saving & low water-pressure startup
  • Battery powered ignition so works well in off the grid setups without electricity
  • Comes with shower head
  • Lower cost
  • Stainless steel panel for anti-corrosion
  • .85 energy factor
  • No certifications
  • Due to .5 water connection vs. standard .75 connection, could be flow issues when needing hot water from more than one point in the house
  • Pipe threads are not American so will need to buy some NPT adapters
  • No warranty details and reviewers have complained about a lack of customer service or water pressure being too low
Dimensions:
15 x 6.3 x 26.8 inches
BTUs:
Unknown
Max Flow Rate:
4.75 GPM
Color:
Silver
Certifications:
None

Our Review

This is a basic tankless water heater that works off propane. It has the necessary protections we like to see and a decent energy factor. It’s also low cost, but there’s not much else to it. It has a higher percentage of 1 star ratings, no certifications, no warranty details as well as a few complaints about a lack of water pressure and customer service. This is too much to overcome in our opinion, thus the low rating.

Marey Power Gas 10L Digital Panel Tankless Water Heater (Propane)

Marey Power Gas 10L Digital Panel Tankless Water Heater (Propane)

5/10
  • Comes with user manual and installation orientations to make it easier to install almost anywhere
  • Compact design with LCD screen
  • No electrical connection required as electrical pulse powered by 2 D batteries
  • .87 energy factor with water temperature control
  • PSI range of 50 to 145
  • Anti-combustion and gas pressure safety protection, rust proof
  • Good for an apartment or small house with 2-3 points of use that might be running at the same time
  • Lower cost
  • Indoor only
  • Warranty is 5 years on parts, 1 year for parts and labor. They will only issue replacement parts, no refunds.
  • Heat can shut off if you switch to cold, though reviewers say it will re-engage if you shut water off and then turn back on
  • It will require more work and some additional spend to install as it has .5 inch equipment rather than .75 inch that many houses have
  • PSI range of 50 to 145, higher minimum PSI to activate than their natural gas version (next option)
  • Inconsistent customer support per reviews
Dimensions:
28 x 15 x 9 inches
BTUs:
79,228
Max Flow Rate:
2.7 GPM
Color:
White
Certifications:
UL, CSA

Our Review

Multiple reviewers mentioned it needs a lot of water flow to kick-in, heating can be intermittent (very hot to cold), and customer support isn’t consistently helpful. With an under $200 price tag and almost half of the reviews being 5 star, it might be worth considering for a limited usage scenario (outdoor shower or small cabin visited from time to time). It does require a bit of work to install and adjust, though it comes with some help via a user manual and installation orientations.

Marey Gas 10L Digital Panel Tankless Water Heater (Natural Gas)

Marey Gas 10L Digital Panel Tankless Water Heater (Natural Gas)

6/10
  • Easy to install almost anywhere, compact design with LCD screen to show water temperature
  • Works with low levels of water pressure with a minimum activation PSI of 10
  • No electrical connection required as electrical pulse powered by 2 D batteries
  • .87 energy factor with water temperature control
  • PSI range of 10 to 145
  • Anti-combustion and gas pressure safety protection, rust-proof
  • Good for an apartment or small house
  • Lower cost
  • Warranty is 5 years on parts, 1 year for parts and labor. They will only issue replacement parts, no refunds.
  • Indoor only
  • Heat can shut off if you switch to cold, though reviewers say it will re-engage if you shut water off and then turn back on
  • This brand’s units don’t work well with single lever faucets
  • Inconsistent customer support
Dimensions:
28 x 15 x 9 inches
BTUs:
79,228
Max Flow Rate:
2.7 GPM
Color:
Silver
Certifications:
UL, CSA

Our Review

This has the same pros and cons as option #12 as is from the same brand. Interestingly, this version that works off natural gas has a lower minimum activation PSI. Given that fact and a lower percentage of negative reviews, we give it a bit higher rating.

Gasland BE158 6L Outdoor Portable Tankless Water Heater (Propane)

Gasland BE158 6L Outdoor Portable Tankless Water Heater (Propane)

7/10
  • Lightweight with LED display and comes with shower hose and mounting bracket for easy installation
  • Works with low levels of water pressure with a minimum activation PSI of 2.5
  • No electrical connection required as electrical pulse powered by 2 D batteries
  • PSI range of 2.5 to 110
  • Safety measures included with flame failure, anti-freezing, and overheating protection
  • Works well for outdoor showers, barns, boats, small off the grid cabins, camp kitchen and shower setups
  • Produces very hot water
  • Lower cost
  • 1 year warranty
  • Need to drain water after each usage if outside temperature is around or below freezing
  • Doesn’t work in strong wind conditions or in altitudes above 3,300 feet
Dimensions:
11.8 x 6.1 x 17.3 inches
BTUs:
41,000
Max Flow Rate:
1.58 GPM
Color:
White
Certifications:
CSA approved regulator and hose, ANSI

Our Review

This product is best for outdoor use, but can be installed indoor with a flue pipe or duct that is well ventilated. It has a very low minimum activation PSI, which is great for outdoor setups. It also provides some of the minimum safety measures we look for. However, the very short warranty and issues with windy conditions and altitude limit it some. Overall, this is a good very low-cost option with indoor/outdoor flexibility.

Camplux Pro BD158 Outdoor Portable Tankless Water Heater (Propane)

Camplux Pro BD158 Outdoor Portable Tankless Water Heater (Propane)

6/10
  • Lightweight with a shower hose and is easy to install
  • Works with low levels of water pressure with a minimum activation PSI of 2.8
  • No electrical connection required as electrical pulse powered by 2 D batteries
  • PSI range of 2.8 to 110
  • Safety measures included with flame failure, anti-freezing, and oxygen depletion shut-off protection
  • Works well for outdoor showers, barns, boats, small off the grid cabins, camp kitchen and shower setups
  • Produces very hot water
  • Lower cost
  • 1 year warranty
  • Low quality shower hose that many reviewers had difficulty with
  • Need to drain when it’s around or below freezing outside
  • Doesn’t work well on windy days
Dimensions:
11.6 x 4.3 x 17.3 inches
BTUs:
41,000
Max Flow Rate:
1.58 GPM
Color:
White
Certifications:
CSA

Our Review

Similar to option #14, this product is best used outdoors and has the same benefits and issues with wind and altitude. It is slightly cheaper as of this writing as well. We gave it a lower rating than option #14 because of the lower quality shower hose.

Tengchang 18L Tankless Water Heater (Propane)

Tengchang 18L Tankless Water Heater (Propane)

7/10
  • .81 energy factor
  • Lightweight, thin-shaped, and comes with a shower hose
  • Works with low levels of water pressure
  • No electrical connection required as ignition powered by batteries
  • Safety measures included with flame failure, manifold, and over water pressure protection
  • Works well for outdoor showers and similar smaller usages
  • It can also be used for indoor showers if ventilated outside
  • Lower cost
  • 3 year warranty for parts
  • Not a lot of reviews or specific details on this product or brand
  • Does not have a drain valve to help prevent against freezing
Dimensions:
26 x 13.6 x 5 inches
BTUs:
Unknown
Max Flow Rate:
4.8 GPM
Color:
White
Certifications:
ISO

Our Review

This product can be used outdoors and indoors with proper ventilation. It also has a 3 year warranty which is 3 times longer than the previous two options! It also has many of the same benefits. The lack of information on this product or brand in general makes us drop the rating and not fully confident in it.

Excel Pro Tankless Water Heater (Natural Gas)

Excel Pro Tankless Water Heater (Natural Gas)

9/10
  • .84 energy factor
  • Minimum activation flow rate of .5 GPM
  • Wall mounted with LCD display and many reviewers found it easy to install
  • Stainless Steel flue included to help with ventilation
  • Delivers instant 35 degree F temperature rise, max temperature of 160 degrees F
  • Certified for installation on manufactured mobile homes
  • Meets needs for most small to medium size houses or apartments
  • PSI range of 10 - 150
  • Works with low levels of water pressure
  • 15 year warranty on heat exchanger
  • Can be used at 6,000 feet elevation
  • Shows the temperature in Celsius
  • Has a little bit of trouble starting when water pressure is too low
  • Warranty only on heat exchanger it seems, not all parts
  • Some reviewers had issues with customer service
Dimensions:
14.5 x 5.5 x 23 inches
BTUs:
140,000
Max Flow Rate:
6.6 GPM
Color:
White
Certifications:
SGS

Our Review

This is a solid product that has a 15 year warranty on the heat exchanger, a low minimum activation PSI, and works up to 6,000 feet. It also includes the stainless steel flue you need for ventilation which a big positive. The temperature registers in celsius and some reviewers had issues with customer service, but getting the stainless steel flue makes this a good deal for smaller houses or apartments.

Bosch C 1050 ES Tankless Water Heater (Natural Gas)

Bosch C 1050 ES Tankless Water Heater (Natural Gas)

10/10
  • .95 energy factor
  • Minimum activation flow rate of .5 GPM
  • 6.3 GPM at 60 degree F temperature increase
  • Works for up to 3 bathrooms or showers and is quiet
  • Wall mounted with digital control panel
  • Compact 2” venting that allows for use of existing vent openings
  • Comes with automated, fully modulating bypass for temperature stability
  • Water heater mobile application for easy access to sizing or technical information
  • Very low NOx emissions
  • External access to inlet water filter
  • 15 year warranty on heat exchanger and 5 years on parts
  • Indoor only
  • Both intake and exhaust vent will need to be purchased if not already available (not included)
  • Per reviewers, install is relatively easy but takes some effort and plumbing expertise
Dimensions:
18 x 11.25 x 30.5 inches
BTUs:
199,000
Max Flow Rate:
9.5 GPM
Color:
Grey
Certifications:
Energy Star

Our Review

This is a well-known and trusted brand. From reviews, people have stuck with this brand for years and been very happy. It has a great warranty at 15 years for heat exchanger and 5 years for parts. It even comes with compact venting to make it easier to work with your existing vent openings and has a very high energy factor and max flow rate. This is our recommendation for someone who needs up to 3 bathrooms or showers taken care of. As of this writing the price is several hundred dollars cheaper than options #19 and #20.

Noritz NR98 Tankless Water Heater (Propane)

Noritz NR98 Tankless Water Heater (Propane)

9/10
  • .88 energy factor
  • 5.6 GPM at 60 degree F temperature increase
  • Works for 2.5 bathroom home and is quiet
  • Minimum flow rate of .5 GPM
  • Wall mounted and comes with a remote control
  • Standard safety features include built in freeze protection, overheat cutoff, flame sensor, and lightning protection
  • Includes automatic scale detection
  • Can purchase indoor or outdoor option
  • Very low NOx emissions
  • Adjustable for high altitude installations
  • 12 year warranty on heat exchanger and 5 years on parts
  • Detailed and informative manual which helps make it easy to install with basic electrical and plumbing knowledge
  • Both intake and exhaust vent will need to be purchased if not already available (not included)
  • Per reviewers, not as quiet as other options (vibration noise that can be heard through shower)
Dimensions:
14 x 10 x 24 inches
BTUs:
199,900
Max Flow Rate:
8.4 GPM
Color:
White
Certifications:
Energy Star

Our Review

This product compares favorably to option #18. We gave it a slightly lower rating because it’s a bit more expensive yet has a lower max flow rate, energy factor, and warranty on the heat exchanger. Detailed instructions and automatic scale detection are also nice features worth highlighting as well. This is our recommended option for a 2 or 2.5 bathroom home.

A.O. Smith ATI-540H-P Tankless Water Heater (Propane)

A.O. Smith ATI-540H-P Tankless Water Heater (Propane)

9/10
  • .93 energy factor for indoor setup, .95 for outdoor
  • 6.3 GPM at 60 degree F temperature increase
  • Works for up to 3 bathrooms or showers and is quiet
  • Built in temperature sensor helps maintain hot water within one degree of set point during use
  • Can purchase indoor or outdoor option
  • Very low NOx emissions
  • Standard safety features include built in freeze protection, manual reset hi limit, overheat cutoff, flame sensor, and inlet and outlet temperature monitors
  • Works up to an altitude of 10,100 feet
  • 15 year warranty on heat exchanger and 5 years on parts
  • Both intake and exhaust vent will need to be purchased if not already available (not included)
  • Per reviewers, install is relatively easy but takes some effort and plumbing expertise. Instructions could be better.
Dimensions:
18 x 11.25 x 23.5 inches
BTUs:
199,000
Max Flow Rate:
9.5 GPM
Color:
Grey
Certifications:
Energy Star

Our Review

If you live at higher altitudes, this is probably your best option among what we reviewed. This has the highest specific altitude of 10,100 feet. It also has a 15 year warranty on heat exchanger, all of the safety features we look for, a high energy factor and a high max flow rate. Only reason it gets a slightly lower rating is because of higher cost and reviewers thinking the instructions could be better.

Don’t see what you’re looking for, or still have questions left unanswered?

Finding a Tankless Water Heater That Works for You

Finding the tankless water heater that works for you really depends on your setup and your needs. Take a walk around your house and think about where the unit would fit and how it could vent if it’s indoors. It’s important to understand your water needs in detail. How many different usages do you have and what is the flow rate (GPM) needed for each? What size gas feed lines do you require? You should also know your groundwater temperature as colder climates may not get to the max temperature advertised.

In the end, consulting with a professional and having them install it is your best bet to get the right unit and the most out of it. Some brands will not honor their warranty unless you have a licensed professional install it. That being said, many handy people have setup tankless water heaters on their own with success.

Here’s what to consider:

  • Fuel Source: Tankless gas water heaters have two different fuel source options – Natural Gas or Propane. Natural gas units are more efficient yet require a setup not available to all homes. Propane can work at any home, indoors and outdoors, and heats up water just as well. However, it is a bit more costly to operate.
  • Flow Rate & PSI: Each of your points of usage will have a flow rate (GPM) requirement at a certain water pressure (PSI). The most common water pressure in houses is 60 PSI. The minimum GPM and PSI can be very important as some units require a higher flow rate and pressure to activate the heater.
  • Energy Factor: This tells you how efficient the unit is. The higher the percentage, the better!
  • Max Temperature or Temperature Increase: This can vary among different brands and units. Some units only go up to 120 degrees F and others can go as high as 185, pending groundwater supply temperature. Some brands will be more specific about flow rate (GPM) at certain temperature increases which is informative and helpful.
  • Warranty: There are a variety of warranties from brands, ranging from 1 year to 15 years. Make sure you read the fine print and register your product warranty immediately. Some companies will not honor the warranty if you don’t register within 30 days or if you don’t have a professional install the unit.

Another detail to keep in mind is that for most tankless water heaters there will be a bit of a delay between turning on water and having hot water. We also suggest you follow any manufacturer suggestions for upkeep like filtration and scale inhibitors. With so much to consider, we took a look at 20 different tankless gas water heaters to help you on your search. We focused on low to reasonably priced models that are under $1,500.

Don’t see what you’re looking for, or still have questions left unanswered?

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