Top 5 Best Condensing Tankless Water Heater Reviews in 2020

Are you still facing the same problem where the gas and energy bills are way too much every month because of your tankless water heater? Do you want to get the ones that can help you save on the heating bills? If that so, then have a glance at the condensing tankless water heaters. Compared with the conventional propane or natural gas tankless water heaters, this type of water heater can really adopt two heating exchangers for reducing the greenhouse gas and energy consumption effectively, a few of which can really reach as high as 0.99EF or 0.97UEF which is super-efficient in the energy consumption.

The condensing tankless water heaters are becoming even more popular all across the world because of the rising gas prices and lower operating charges. In this post, you will be guided about the condensing technology in detail, and we will also provide some of the best reviews for helping you out in getting the best one.

How Does A Condensing Tankless Water Heater Really Work?

As mentioned earlier, the condensing systems can really adopt the two heat exchangers. One really obtains heat from the gas burner directly while the secondary elements are appended, usually the stainless steel materials for recovering the waste gas from the flue gases. The efficiency of the energy can really reach as high as ninety percent through such a smart design. It can really resolve the issues of gas wastage to a huge extent.

Such design also can recover the heat that’d be lost in the non-condensing tankless water heaters. It leads to less carbon dioxide emissions and energy consumption. Besides, it also can keep the exhausted temp low that you can use the cheaper venting, like the economical Schedule 40 PVC pipe, in almost all the applications.

Why Should You Select The Condensing Type?

In North Europe, the condensing tankless water is also recognized as the condensing boiler. The water working procedure is completely the same as there is in the conventional tankless water heaters. However, as the most well-liked models in Canada and America, what troubles most of the conventional units are the lower energy efficiency, a huge amount of heat and gas energy are wasted as the burning of flue gases are vented out.

For fixing the issue, the best tankless water heaters brands like Takagi, Rheem, and Navien, etc., really adopt the condensing technology onto the water heaters they manufacture. The exchangers are the main elements in the condensing procedure; both contribute much in capturing the wasted gas and cooling combustion products that’s the reason why the heating exchangers of condensing tankless water heaters have to be a lot more efficient and larger than the conventional machines.

Getting the best water heater denotes you’re capable of saving as high as ninety-eight percent heating energy each month, which assists in saving large money in the heating costs. Also, it can protect the global atmosphere by emitting less carbon dioxide. For starters, the condensing units are often utilized in America as the commercial tankless water heaters, but because of the low operating costs and heating costs of these, they’re getting even more well-liked as the residential tankless water heaters these days.

Features Or Advantages Of The Condensing Tankless Water Heaters:

  • They’ve less heating costs and operating costs
  • The best condensing can saves as high as ninety percent energy-efficient.
  • They’re highly eco-friendly equipment with less NOx and CO2 emission.
  • Perfect for the high demanding commercial or homes use
  • The cost can be a little higher than the normal tankless units.
  • They use the cheap PVC venting because of the low combustion temp
  • They require more maintenance
  • The installation is quite difficult, which is suitable for expert installation.
  • No need to purchase any extra larger tank system

Comparison Of The Condensing & The Non-Condensing Tankless Water Heaters:

 The Condensing Tankless Water HeatersThe Non-Condensing Tankless Water Heaters
Required Installation Time4 to 8 hours4 hours
GPM (Maximum)9810.1
Gas Pipe¾” pipe typicallyCan utilize existing ½” pipe
VentingOther Type (Not PVC)2” PVC
Energy Factor0.82 EF0.99 EF/0.97 UEF
Input199000 BTU per hour180000 BTU per hour
Output~ 163000~ 178000


The condensing tankless water heating system is more costly than the conventional models, but it is very energy-efficient; for a long using time, using charges can also be way less than the non-condensing devices. We made best condensing tankless water heater reviews for helping you out in selecting the most suitable device for you. you can check out these reviews down below:

Top Condensing Tankless Water Heaters Reviews:

1. Takagi T-H3-DV-N Condensing Natural Gas Tankless Water Heater:

Takagi T-H3-DV-N 2020

The first condensing tankless water heater we’d want to suggest is the Takagi natural gas tankless water heater, it’s actually a commercial unit, the water flow rate can reach as high as ten GPM. The heat exchangers of this unit for condensing are created of stainless steel material, which is extremely corrosion resistant and has an extended service life. Much wasted gas and energy are saved because of such a design. The released temp of hot water can reach as high as 185 degrees Fahrenheit, and it can demand 199000 British Thermal Units per hour for the perfect performance.

As the water flow rate and needed power range are very high, it’s great to be utilized for the commercial tankless water heating machine or for the family in huge demand for the heated water. If you want to get a residential model, you might contemplate the following recommendations. Do not be terrified by its large water flow rate, it is actually very light, and will take up just a small piece of land. The setting up of the device is also very simple; simply append some gas line on it.


  • Weight light
  • Large water flow rate
  • Can be remotely controlled
  • Easy setup
  • The most perfect one for the commercial usage
  • High-temp water offered


  • The hot water waiting time is a little long
  • The water flow rate might be lowered in the colder regions
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2. Noritz NRC661-DV-NG Condensing Direct Tankless Hot Water Heater:

Noritz NRC661-DV-NG Condensing

For better saving the energy, this tankless water heater by Noritz also comes with two heating exchangers; one is created from the copper while the other one is stainless steel material. They’re utilized for recovering wasted gas and getting direct heat. Because of such a condensing design, the thermal efficiency of it can reach as high as ninety-three percent. The consumption of gas of it this unit runs between 15000-120000 British Thermal Units per hour.

Compared with the other suggested tankless water heating systems, this one is appropriate for the residential usage, the water flow rate between 0.5-6.5 gallons per minute, which can suit house hot water demands flawlessly. It’s also capable of supplying hot water for two bathrooms in the southern parts and one and a half in the northern areas. If you live in the colder region, then the freeze protection device can smartly sense under zero temp and takes action for protecting itself.


  • Quiet working condition
  • Endless supply of hot water
  • Protects part in the colder areas
  • Can be vented with the Schedule 40 PVC pipe
  • Low NOx design
  • Twelve years of warranty for the heating parts


  • Coldwater sandwich
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3. Rinnai RUR98iN Ultra Series Heater:

Rinnai RUR98iN 2020

This one is always the most praised and hot-selling natural gas tankless water heating unit. Because of the condensing design it comes with, there’re dual venting options you can pick from, both with inexpensive materials, comprise twin pipe and concentric PVC. We all acquaint that the natural gas tankless water heating set is normally with the large power, certainly, it’s not an exception. The water flow rate of this tankless water heater is 9.8 GPM, with power requirements can range from 15200-199000 British Thermal Units.

Rinnai is a brand with a ground-breaking spirit; it manufactured a lot of trials, and productively reached its product’s energy rating around 0.95. Though in large water flow rate and large power, it’s simply started, requires just two watts for keeping the device up and running. The cost of this unit is quite a lot among the other available Natural gas tankless water heaters, but when utilized for an extended time, you’ll acquaint how shrewdly you’re in getting this machine. All the designs, comprising the condensing technology and the internal heat structures, provide the users with the best operating experience and save a huge sum of heating charges for you.


  • Provides two venting options
  • High-temp range
  • Accessible for commercial usage with the commercial remote
  • Hot water supply for the several applications
  • Quiet working condition
  • Fast heating time


  • Hard to install, you have to hire a professional to do the job
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4. Rheem RTGH-84XLP Condensing Propane Tankless Water Heater:

Rheem RTGH-84XLP 2020

This tankless water heating machine is also a very energy-efficient one, with its stainless steel condensing heating exchanger; the energy-efficient of this model reaches as high as ninety-four percent. When utilized for the residential unit, the 8.4 gallons per minute water flow rate is capable of supplying perfectly hot water both for the kitchen and bathing use. If you want to utilize it as the commercial tankless water heating device, you can manifold up to six devices by utilizing the optional MIC-6 manifold control board.

Also, it’s capable enough for commercial use, the best 0.26 gallons per minute minimum water flow rate and forty gallons per minute minimum activation water flow rate can really suit the large water demand. You can make use of this device using the remote control, and there are ten feet of thermostat cable included. However, the buying cost can be a little high, but if you’ve enough budget on purchasing this, you’ll find it extremely cost-effective.


  • Intelligent electronic control
  • Ninety-four percent energy efficient
  • Digital temp display
  • Self-diagnostic system
  • Eco-friendly low NOx design
  • Built-in electric blower


  • Has to be installed by experts
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5. Naiven NPE-240-A Tankless Gas Water Heater:

Naiven NPE-240-A

The water heaters by Navien are well-known for the satisfying user experience and smart design they have, particularly for the NPE-A series, a lot of high technologies are appended for saving energy and decreasing the heating charges. Certainly, this device has the condensing technology, but what worth most mentions are the fitted the recirculation pump and the insulated buffer tank; it’s said the series of heating units are the first and only ones that have such devices.

With the buffer tank, you can really save much cash on purchasing an additional water tank and eradicate the cold water sandwiches efficiently. While the recirculation pump cuts down the hot water waiting time, thus water and heating bills are both saved. The flow rate is very large, allowing supporting multiple kitchen faucets and bathrooms simultaneously. When in bathing, you don’t have to be anxious about running out of the heated water.


  • Clear installation and utilizing instructions
  • Satisfying consumer service
  • Pretty powerful
  • Requires just one second for the hot water
  • External interface, error codes and water temperature turn the device off simply using a button
  • Good at keeping the water temp and hot water flows pretty quick after switching on


  • A little hard in installation
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Summing Up:

  • Rinnai RUR98iN Tankless Water Heater is the hot-selling model.
  • Takagi T-H3-DV-N Tankless Water Heater is the best device for commercial use.
  • Naiven NPE-240-A Tankless Water Heater is the best technological machine.
  • Noritz NRC661-DV-NG Tankless Water Heater is the best cost-effective model.
  • Rheem RTGH-84XLP Tankless Water Heater is the best one for the large hot water demand.

The best condensing tankless water heater cost is usually much higher than the non-condensing ones because of the special design it has, however, it can also assist in saving much energy, which denotes that the heating charges and hot water charges will be decreased to a great extent. Therefore, though having high buying costs, for the long-time usage, you’ll find that using charges of these units will be even cheaper than the non-condensing one.

The condensing tankless water heaters that we have mentioned above are the best models, and they are all tested. If you desire to know more about all the models (e.g., price and detailed features), then feel free to visit and check on Amazon.