When you buy through links on our site, we may earn an affiliate commission at no cost to you.
There’s practically a good reason why having the best tankless water heater at home could be one of your life’s significant options. And here’s why.
Having regular hot water has always been an essential requirement for every home. We use hot water for showers, washing the dishes and cleaning our clothes. But should we always have to buy water tanks just to keep stock on hot water?
Water tanks usually last 10 to 13 years and require regular cleaning maintenance. More so, maintaining 40 to 60 gallons of hot water every day in a tank can really take a toll on your gas or electricity bill.
So my point is, why not opt for the best tankless water heater that could sustain you the hot water you need on demand, get more savings on energy use and can surpass years of use compared to the tanks?
- 1 Gas vs. Electric Tankless Water Heater
- 2 Top 10 Best Tankless Water Heater 2020 Reviews
- 2.1 1. Takagi T-H3-DV-N Condensing High Efficiency Natural Gas Indoor Tankless Water Heater
- 2.2 2. Rheem RTG-64XLN 6.4 GPM
- 2.3 3. Takagi T-KJr2-IN-NG Indoor Tankless Water Heater, Natural Gas
- 2.4 4. EcoSmart ECO 27 Electric Tankless Water Heater
- 2.5 5. Stiebel Eltron Tempra 24 Plus Electric Tankless Whole House Water Heater
- 2.6 6. Bosch T 2.5-Gallon Electric Mini-Tank Under Sink Water Heater
- 2.7 7. Eccotemp L5 Portable Tankless Water Heater and Outdoor Shower
- 2.8 8. Eccotemp FVI-12-LP High Capacity Propane Tankless Water Heater
- 2.9 9. Stiebel Eltron Tempra 29 Plus Electric Tankless Whole House Water Heater
- 2.10 10. Rinnai RL75iN Natural Gas Tankless Water Heater
- 3 Consider These When Buying Your Best Tankless Water Heater
- 4 Conclusion
Gas vs. Electric Tankless Water Heater
Tankless water heaters are available in two general types, the gas and the electricity powered heaters. For your info, tankless gas water heaters generally use natural gas that is cheaper to buy and can also heat up elements faster and more efficient. On the one hand, the electric type water heaters have longer service life, easier or cheaper to install and offer smaller operating costs.
Here, we have put up the 10 tankless water heater reviews to show you the top of the line units (tankless water gas and electric water heaters) that any home deserve to have.
Top 10 Best Tankless Water Heater 2020 Reviews
1. Takagi T-H3-DV-N Condensing High Efficiency Natural Gas Indoor Tankless Water Heater
This tankless gas heater could best suit your household need as it can supply everyone in your family with endless hot water on demand. It has many uses too like your radiant floor system if you install it in your basement and heat up your floor during winter. It can also be your recirculation water system if adequately installed so that every faucet in your home can get hot water from it.
This Japanese made unit offers ultra-low NOx condensing technology, meaning, there’s almost no toxic fumes that will come out of it so even you install it under your basement with very little ventilation, you’ll be safe.
With gas heat input of about 180,000 BTU, many homeowners confide that this can supply non-stop hot water on 2 bathrooms even in cold weather. With a heat exchanger made up of copper alloy for quick water heating, this is also ENERGY STAR approved.
Our Rating: (4.3 / 5)
- Made in Japan.
- Uses natural gas (.95 energy factor).
- Heater only turns on when a water tap (faucet or shower) is opened and shuts off once tap is turned off.
- Heat requirement – 180,000 BTU.
- Flow rate: 8 GPM (gallons per minute) at 35 degrees Fahrenheit.
- Heat exchanger made from HRS35 copper alloy.
- With built-in computerized safety mechanism to prevent overheating and freezing.
- Surge protected and with troubleshooting diagnostic codes.
- Burner passed the 2012 SCAQMD Rule 1146.2.
- ENERGY STAR approved.
- Ultra-Low NOx Emissions.
- Can be remotely controlled (comes with remote control).
- Very compact with sleek, attractive design.
- Comes with installation guide (also downloadable).
- Limited 5-year warranty on heat exchanger (residential use).
- Needs specialized gas lines to handle high volume of gas to meet up BTU requirement.
- Requirement for high quality pipes may add up to the overall installation expenses.
2. Rheem RTG-64XLN 6.4 GPM
This amazing product from Rheem can give you hot water around 4 to 6 GPM (depending on altitude and weather) thus using 2 showers plus sink simultaneously would not be a problem. With its “simultaneous usage” feature, it has an energy efficiency of 0.82 rating and requires around 150,000 BTU from natural gas (methane) to turn its copper heat exchanger blazing hot.
Following environment safety standards, this product is also a certified “Low NOx” unit but was designed for outdoor installation so it would be better if you put up a shade for it. Weighing only 54 pounds, the convenience your get from its remote control is a lot. It can also be manually operated using its long thermostat wire so there’s no need to go out to operate it.
Our Rating: (4.5 / 5)
- Easy to install. Comes with an installation illustration.
- With sensor that prevents start up until everything in its system is properly hooked up.
- Heats up water only as needed.
- Capable of simultaneous tap or shower usage.
- Lightweight and uses natural gas.
- Hot water output is 6.4 GPM on fair weather.
- With remote control and 10 feet thermostat wire for manual control.
- Low NOx version.
- With manual gas isolation valve.
- Burner passes SCAQMD rule 1146.2 requirements.
- Need to have ¾” gas line.
- Must have service valve kit for maintenance.
- Not for inside home installation.
3. Takagi T-KJr2-IN-NG Indoor Tankless Water Heater, Natural Gas
This Made in Japan unit has been raving good reviews all over. As a top quality water heater, it is one of the most compact units that can provide continuous hot water on two bathrooms at the same time.
This unit only needs 140,000 BTU to fire up and as tested, it can equal the heating capacity of a 40-gallon tank water heater. With a flow rate of 6.6 GPM, it can serve households better that need hot water without interruption.
Equipped with a thermistor (temperature sensor), this will ensure that the temperature of the water remains as set and the machine will automatically shut down once the water temperature goes above the set temperature.
It is also features an Air Fuel Ratio sensor that keeps track on its emission. This will tell you if there are harmful pollutants coming out of its exhaust.
Our Rating: (4.4 / 5)
- Made in Japan.
- Easy to install. Comes with a schematic catalogue and step-by-step installation manual.
- With automatic thermistor sensor to monitor water temperature.
- Featured with an air fuel ratio sensor to keep track for harmful emissions.
- Surge breakdown protector, freeze protector and digital meter protector to guard against system failures.
- Can be relied for radiant heating applications.
- Hot water flow rate of 6.6 GPM.
- Heating requirement – 140,000 BTU.
- Built-in advanced switches to adapt to various altitude up to 6,000 feet.
- Low maintenance cost.
- Energy-star certified. Energy factor is 0.81 to 0.83.
- Minimum life span: 10 years.
- Perfect for apartment units or medium size homes.
- Warranties: 10 years on heat exchanger, 5 years on parts for residential use and 3 years for commercial use. Warranty is valid only if installed by a licensed technician.
- Expensive installation if you hire a professional technician though this comes with increased safety.
- May not supply enough hot water on taps when used simultaneously with showers.
- Requires a 4-inch category III vent pipe for ventilation.
4. EcoSmart ECO 27 Electric Tankless Water Heater
Considered by many homeowners to be a very reliable tankless electric water heater that can handle hot water on demand even on frigid climates, the ECO 27 is also one of the favorites among cabin, lake house and vacation home owners. With a price that justifies its essentials, this could be your best choice for your medium-size home as long as there’s electricity to power it.
Now, what makes it rise above its competitors is the unit’s self-modulating flow sensor which control its use of electricity. The result is higher energy efficiency while meeting your desired water heating requirements.
This unit is installed with 3 heating elements that work in series and only draw voltage on demand so it could save you up to 60% on your water heating bills.
And unlike other electric tankless water heaters, that won’t work on very low temperatures, the ECO 27 is designed to work on colder climates. So even your water is as cold as 37 degrees Fahrenheit, this unit can heat it up to 105 degrees Fahrenheit at 2.70 GPM flow rate.
Our Rating: (4.2 / 5)
- With digital temperature control.
- Features 3 heating elements that heat up water successively.
- Heat water on demand at 2.70 GPM.
- Configured for cold climates but perform best on fair climates.
- Best choice for medium-size homes with 3-5 residents.
- Around 50-60% savings on energy bill.
- Self-adjustable power usage and pressure settings to provide consistent output.
- Heat exchangers are made of copper and stainless components.
- Compact and has attractive design.
- Lifetime warranty.
- May not work best on high altitudes or far north regions.
- Warranty may be voided if unit is not registered or improperly installed.
- Limited GPM (hot water output).
5. Stiebel Eltron Tempra 24 Plus Electric Tankless Whole House Water Heater
This product is a fresh addition in the market among tankless electric water heaters. It features a bright digital temperature monitor that will let you program it easily and monitor the water temperature at a glance. It also has an advanced flow rate sensor that controls the water temperature and prevents it to exceed beyond its set point. With a 4.0 GPM, this can supply hot water on two water outlets continuously and simultaneously.
According to Stiebel Eltron, this is the best tankless water heater when it comes to preventing risks to households such as accidental water overheating. And as expected from all electrical appliances, it won’t produce fumes also unlike gas heaters.
With a nice design and robust construction, this product is well praised by many to be the best tankless water heater among electrically powered tankless water heaters and very much energy efficient too as it only produces hot water on demand.
Our Rating: (4.7 / 5)
- Equipped with a digital temperature control with monitor for easy setting and monitoring of water temperature.
- With advanced flow rate sensor that efficiently controls water temperature.
- Adaptable to all kinds of weather.
- Compact and beautifully designed.
- 99% energy efficient. Can save around 20% on electric bill in terms of hot water usage.
- No requirement for venting.
- 3-year warranty.
- Need to have someone skilled on home electrical system to set this up.
- Capable only to provide efficient hot water on two fixtures at the same time.
6. Bosch T 2.5-Gallon Electric Mini-Tank Under Sink Water Heater
One of the most popular POU (point-of-use) tankless electric water heaters in terms of under the sink versions are the Bosch T versions. It has 3 sizes but this one features 2.5 GPM.
This is basically a mini-tank heater that can be wall-hung (bracket included), floor-mounted or as its name says, best for under the sink. In this case, we expect it to be compact, no fumes, no noise and won’t take any precious space in your kitchen or bathroom.
For the matter of installing it, you just need to tap it into your cold water supply. Or you can install it in-line with a bigger hot water source to eliminate waiting time for your hot water supply. It can supply 2 sinks at the same time so even yacht or RV owners will love to have this under their sink especially when spending vacations on colder weather.
Our Rating: (4.5 / 5)
- Easy to install. Just tap on cold water line.
- Easy to control temperature range.
- With pressure release valve for added safety.
- The right size for under the sink.
- Best choice for any home sink, bathroom faucets, basement wet bars, RVs or boats.
- Perfect choice as an extension for your larger tankless water heater.
- Maintenance free and glass lined for long service life.
- Fast recovery that reduces long waits for hot water.
- Can be mounted on walls or floors.
- Elegantly designed exterior.
- Size: 13.75 W x 13.75 H x 10.75 D, weight: 15.5 lbs.
- 1 year warranty on parts.
- Amp capacity is 12 Amp but start up may draw power up to 15 amps which can trip breakers with low amps.
- Monitoring and cleaning of calcium build-up internally may be regularly required if tapped on hard water system.
7. Eccotemp L5 Portable Tankless Water Heater and Outdoor Shower
If you want the best tankless water heater on the go, I can recommend you this bestselling portable tankless water heater. You can carry it wherever you go. As long as you have its liquid propane gas tank along and a water hose ½” to connect to, this can provide you a maximum of 1.4 GPM of hot water for your shower.
You can keep this in your RV, boat, farm, cabin or in your campsite and will be your perfect water heater for your outdoor shower.
You can easily adjust Eccotemp L5’s water temperature from 80 to 150 degrees Fahrenheit. And because it requires only 20 psi wherein the maximum for home showers is 80 psi, you can absolutely get continuous hot water on point-of-use.
To give you a good estimate, its 20 pound tank of propane can last 18 hours of hot shower. You will need to buy 2 “D” batteries for it though. These will serve as spark generator to start up fire internally.
Our Rating: (4.3 / 5)
- Very easy to set up and use.
- Provides instant hot water.
- Complete with accessories (CSA approved regulator, 1/2” hose with a shower head, garden hose adapter, heat shield and an instruction manual) except batteries and tank.
- Uses liquid propane for quick outdoor heating.
- Minimum flow rate: .3 liters per minute.
- Adjustable water temperature from 80 to 150 degrees Fahrenheit.
- Requires only 20 psi for the shower but can handle 100 psi maximum.
- Requires 37,500 BTU.
- Timer that automatically shuts the unit down every 20 minutes for added safety.
- Weighs only 14 pounds.
- 1 year limited warranty on parts.
- Can have issues in maintaining internal flames on windy environment.
- Some of its accessories are said to be poor quality made.
- For outdoor use only. Not to be fixed on any water fixtures inside homes.
8. Eccotemp FVI-12-LP High Capacity Propane Tankless Water Heater
This tankless gas water heater also uses liquid propane to fire up its heater and capable to produce 3.4 GPM of hot water. Designed for home use, it can adequately supply 2 flow-restricted showers simultaneously. It features a digital LED display to enable you to see its current water temperature but must be manually controlled to set up your desired temperature.
There are two knob regulators on its control panel. One is to control the gas flow and the other knob is to control the water flow. In this case, you have to adjust both when setting up for your desired water temperature.
The actual activation flow of this product is 0.93 GPM at over 30 PSI. This means that the higher water pressure you’ll be tapping this unit, the more GPM of hot water you’ll get.
This is also best for cabins or cottages installation and can heat water on demand especially for showers.
Our Rating: (3.9 / 5)
- Uses liquid propane (standard 20 pound propane tank).
- Requires only 74,500 BTU.
- Maximum up to 3.4 GPM.
- Manually operated/adjustment with digital LED display.
- With adjustment screws to adjust sensitivity to water pressure.
- Includes 2 ¼” horizontal stainless steel vent.
- 110 volts, this only consumes 110 watts of power during heating and 2 watts on idle mode.
- 2-year warranty.
- Requires ½” NPT fittings.
- Not equipped with automatic water temperature control.
- Need to master adjusting the regulators to get the desired water temperature.
- Would not heat up water with below 30 psi.
- Parts for the exhaust vent are not easy to find.
9. Stiebel Eltron Tempra 29 Plus Electric Tankless Whole House Water Heater
This Tempra 29 is an advanced version of the Tempra 24 but with the same positive features and some additional advantages. For its specs, you can install this near your water fixtures and because it uses 240 volts of electricity at 150 PSI water flow, you can expect that you get hot water on demand and fast from your faucet and two showers.
With a capacity of 4.37 GPM, you can also adjust the water temperature from 86 degrees to 125 degrees Fahrenheit. For such a small unit, you can say this can be your best tankless water heater among the residential compact versions. Weighing only 17 pounds, you can mount it on your bathroom’s wall, under the sink or fix it inside your kitchen closet.
Our Rating: (4.3 / 5)
- Output: 4.27 GPM.
- Maximum heating: Up to 125 degrees Fahrenheit.
- Capable of simultaneous usage on a number of water outlets but not exceeding three.
- With dials for adjusting the desired water flow and the desired water temperature.
- Temperature settings: 80 to 125 degrees Fahrenheit.
- Offers long term energy savings from 15% to 20%.
- Capable to handle water flow of 150 PSI.
- Sleek design.
- 3-years limited warranty if installed by licensed personnel.
- Difficult to install.
- Must be installed by a technician to check amp requirements, available amp breakers, ground lines, electrical box and circuits.
- Flow delays when more than two water outlets are opened simultaneously.
10. Rinnai RL75iN Natural Gas Tankless Water Heater
This Rinnai RL75iN belongs to the Rinnai’s Luxury Series. As a natural gas user, it gives you water on demand but with an energy savings on the side.
As an indoor water heating unit, it can deliver 7.5 GPM and can supply hot water for three showers open at the same time plus one sink. According to the American Water Works Association that tested this product, with three showers on, you still get an average flow rate of 2.2 GPM for each while the standard flow rate is only 1GPM per shower.
With a 7.5 GPM, that equals to 28.5 L/minute at 40 degrees Fahrenheit rise. You can also set its heater to heat up water up to 110 degrees Fahrenheit.
This unit can put up 180,000 BTU. And although a 165,000 BTU is enough to heat up water for a small family, the maximum heat this unit is capable of exceeds those of the standard heaters.
Our Rating: (4.3 / 5)
- Uses natural gas or propane.
- Can supply hot water on 3 showers and one sink.
- Capable of delivering 7.5 GPM.
- With direct electronic ignition system to lights up the burner.
- Uses 120 V current but consume only 2 watts power on standby.
- Energy Star certified.
- With a temperature controller integrated into the front panel for easy set up and control.
- Temperature settings: 98 to 110 degrees Fahrenheit.
- Front panel with On/Off button, power indicator, Priority button and Priority Indicator.
- Show warning codes when error occurs.
- LED display.
- Certified for installation even for mobile homes.
- Can adapt to 10,200 feet elevation.
- Meets Texas and California NOx emissions standards.
- Can be used for commercial uses.
- Warranties: 12 years on heat exchanger, 5 years on parts and 1 year on labor for residential installations.
- Requires ¾ supply lines and ¾ inch gas pipe.
- Can heat up water really hot if water temperature is not monitored during malfunctions.
- May require at least one annual cleaning (flushing) or as recommended.
- It only comes with valves. The rest of the accessories must be purchased separately.
- Must be installed with a vent as it uses air for combustion.
- Requires about 180,000 BTU/per hour during simultaneous use.
Consider These When Buying Your Best Tankless Water Heater
Replacing your tank water heater with the best tankless water heater could be your best investment when it comes to finding a more energy efficient option for your hot water needs. But with all the various brands and models being sold today, there goes the confusion. So which one?
Here are the features you should therefore look for.
1. Will it need to be gas or electric?
If you are contemplating for the tankless electric water heater, you must consider that you have to have the right voltage and amperes with your main electrical box based from your model heater type. Or can you afford to have its own circuits?
For the gas types which commonly use natural gas, do you have a gas supply line ready? If there is, can this fit with the tankless unit of your choice?
2. Does it require venting?
If the tankless water heater is for outdoor installation, you definitely need to install it outdoor or have a proper venting system if you’ll fix it in your basement. Even with low NOx, any heater with emission should have vent that exhaust outside the house. In case there is retrofitting required, go for it.
3. Consider the Flow Rate/Demand
Which fixtures would you want to connect your tankless water heater to? Showers and dishwashers use a lot of hot water while faucets use less. In this case, you can choose a unit that can provide hot water on fixtures and showers simultaneously.
4. Heating Capacity
On this part, you need to identify the unit’s heating capacity against the water flow rate in PSI, the temperature of incoming water, the elevation where your home is located and the weather around it. Higher BTU capacity means quicker water heating although this spells more energy use.
The actual advantages you get from the best tankless water heater are really a lot. With a big savings on energy use and space, longer lifespan and better technology features, more and more people are now switching from their standard water heater tanks to the tankless types.
Tankless water heaters are also cheaper to buy, feature low NOx especially these top 10 heaters and they can be your best investment in terms of providing your family their basic needs specifically during the colder days.
However, for me, the best tankless water heater is the Takagi T-H3-DV-N. Why? First, it is made in Japan and therefore uses Japan’s technology. Second, with its innovative features, I feel like I can get all the features I need exactly from a water heater.
And finally, with a 180,000 BTU, I trust that I could continuously get hot water even on cold weather. It also has an amazing 8 GPM capacity so I could have my hot shower and use my dishwasher at the same time.
How about you? Any of these could be your best tankless water heater and should suit your needs especially the electric types if you don’t like the little fumes. They can be your conventional energy saving heaters on a more compact package.
Please share this best tankless water heater review if you have a friend thinking about switching or buying the tankless type water heater.