Rheem Tankless Water Heaters Reviewed

Gary Johnson
Written by
Last update:

Here’s everything you need to know about Rheem tankless water heaters.

In this guide I’ll reveal how these heaters compare to their competitors, how they work, what they cost, and whether this is the right type of heater for your home.

After this guide you’ll know all you need to know about Rheem tankless water heater.

NameCategoryProduct
Rheem 240V Heating Chamber RTEX-13 Residential Tankless Water HeaterBest OverallRheem 240V Heating Chamber RTEX-13 Residential Tankless Water Heater
Rheem RTEX-18 18kW 240V Electric Tankless Water HeaterBudget PickRheem RTEX-18 18kW 240V Electric Tankless Water Heater
Rheem RTG-84XLN 8.4 GPM Low NOx Outdoor Tankless Natural Gas Water HeaterUpgrade PickRheem RTG-84XLN 8.4 GPM Low NOx Outdoor Tankless Natural Gas Water Heater

1. Rheem 240V Heating Chamber RTEX-13 Residential Tankless Water Heater

Our rating: 9 / 10

Rheem 240V Heating Chamber RTEX-13 Residential Tankless Water Heater

Check Price on Amazon

Pros:

  • Very easy and safe to install
  • Heats water 1-2 times faster than a gas water heater
  • Huge energy and money savings
  • Can run continuously for up to 4 days
  • Can heat water for whole house
  • 25-year tank warranty

Cons:

  • More expensive than traditional water heaters
  • Has a more complicated installation process

After looking at a wide array of reviews and tankless water heaters, I found the Rheem 240v Heating Chamber RTEX-13 to be the best one. It’s likely to be the most economical tankless water heater for you to purchase right now.

This tankless water heater is by far the most easy-to-install model on the market. The single system coupled with the quick-connect fittings, a compact design, and replaceable anode inserts make for a worry-free installation. There are absolutely no special tools required to get this heat pump up and running.

2. Rheem RTEX-18 18kW 240V Electric Tankless Water Heater

Our rating: 8 / 10

Rheem RTEX-18 18kW 240V Electric Tankless Water Heater

Check Price on Amazon

Pros:

  • Very easy to install
  • Withstands harsh weather conditions
  • Doesn’t use much water

Most reviews we found for Rheem’s tankless water heaters showed buyers who were very grateful for “life-changing” energy savings … of which, there were very good reasons for because tankless water heaters in general, including these from Rheem, are very energy efficient compared to the conventional tank water heaters.

The Rheem RTEX-18 can save you up to 97 percent on your monthly heating bill and it works great on well water. It’s also ideal for homes that use hot water for different purposes, not just washing. The Rheem RTEX-18 produces just the right amount of hot water needed for washing, cooking and bathing.

3. Rheem RTG-84XLP-1 Tankless Water Heater

Our rating: 6 / 10

Rheem RTG-84XLP-1 Tankless Water Heater

Check Price on Amazon

Pros:

  • Saves on energy costs
  • Low-cost installation
  • Fridge-like design
  • Doesn’t require drain pipe or venting
  • Energy-efficiency guarantees up to 68% annual energy savings
  • Durability testing proves it has a lifespan of 20 plus years
  • Fast heating
  • Quiet operation
  • Great customer service

Cons:

  • Inexpressive, less-than-polished design
  • Less energy efficiency for large households
  • Rheem uses proprietary connectors instead of standard plumbing connectors
  • Not as competitively priced as some other tankless systems
  • Longer installation process than standard water heaters

Considering the pros and cons above, the Rheem RTG is worth the money and is indeed one of the best tankless water heaters on the market. Rheem is owned and run by The Johns Manville Corporation which has an impeccable reputation. The RTG-84XLP-1 Tankless Water Heater is guaranteed to last for at least 20 years with no breakdowns, leaks or issues of any kind.

4. Rheem RTGH-95DVLN 9.5 GPM Indoor Direct Vent Tankless Natural Gas Water Heater

Our rating: 6 / 10

Rheem RTGH-95DVLN 9.5 GPM Indoor Direct Vent Tankless Natural Gas Water Heater

Check Price on Amazon

Pros:

  • Great Gas Savings
  • Can Save up to 75% in your Fuel Bill Over Traditional Gas
  • Easy-to-install but can be difficult on your hands

This unit has the capacity to furnish continuous hot water at rates of up to 95 GPM. However, in actual performance, it only provides 9.5 GPM due to the hydrogen generation, which converts the oxygen (that is in the pipes) into hydrogen, when it is in operation. But if you combine it with a two-stage gas water heater, which is a separate heat that is fired firstly, and, after it reaches a point of being hot enough, then the main heat shut off-it functions in tandem and provides uninterrupted service.

Caution: This device requires you to have an electrical outlet in the range of 20-50 amps. But a breaker should not exceed 50 amps. So it is better to have a service panel that is 50 amps, one at each end of the circuit, so that they may not push more than their limit. Restricted to homes, but mostly found in businesses.

5. Rheem RTG-84XLN 8.4 GPM Low NOx Outdoor Tankless Natural Gas Water Heater

Our rating: 6 / 10

Rheem RTG-84XLN 8.4 GPM Low NOx Outdoor Tankless Natural Gas Water Heater

Check Price on Amazon

Pros:

  • Multiple settings
  • Auto reset if the water level drops
  • Built-in thermal overload protection
  • Works with natural gas and propane
  • Anti-corrosion drainpipes
  • Bolted gas tank connection

Cons:

  • LED pilot light turns on and off
  • Not as quiet as advertised
  • Only works with water pressure above 45 PSI

If you´re looking for the best Rheem tankless water heaters to buy, this Rheem RTG-84XLN 8.4 GPM Low NOx Outdoor Tankless Natural Gas Water Heater is hard to beat. It is one of the highest rated Rheem products on Amazon and has one of the highest customer satisfaction ratings in the industry.

There are lots of reasons to go with this model. It is one of the best outdoor tankless water heaters in the industry thanks to its performance and features. The 8.4 gallons per minute that this model is capable of deliver is one of the highest in the industry. It also has a stainless steel heat exchanger, an anti-corrosion drainpipes, and a gas tank made of stainless steel.

6. Rheem RTGH-95DVLP 9.5 GPM Indoor Direct Vent Tankless Propane Water Heater

Our rating: 5 / 10

Rheem RTGH-95DVLP 9.5 GPM Indoor Direct Vent Tankless Propane Water Heater

Check Price on Amazon

Pros:

  • Cheapest option in the Rheem line
  • Very efficient
  • Very easy to install

Cons:

  • Heavy
  • Expensive compared to other Rheem models
  • Short warranty period compared to other models

95,000 BTU.

The RTGH-95DVLP is the cheapest model in the Rheem line of tankless water heaters. It has a variable power setting system, along with a natural gas model.

The 95DVLP is best used for smaller water heater applications, up to 6 showers per hour, 6 to 12 baths per day, and up to five 3-minute kitchen taps per hour. It also has a warranty period of only 2 years for an entire home application, while other models in the Rheem line have a warranty period of 5 years.

7. Rheem RTE 9 3 GPM Electric Tankless Water Heater

Our rating: 5 / 10

Rheem RTE 9 3 GPM Electric Tankless Water Heater

Check Price on Amazon

Pros:

  • Fast recovery
  • Solid product

In the tankless water heater reviews, the first product I’ll be covering is the Rheem RTE 9 Electric Tankless Water Heater.

This model offers all the latest functionalities, including a super fast recovery and a remote tankless controller. It can provide a flow rate of up to 3 GPM.

According to reviews, this unit is known for long-lasting performance and operational efficiency.

Frequently Asked Questions (FAQ)

Is Rheem a good tankless water heater?

Rheem water heaters have a great design and is easy to install. The heaters come in a variety of models to match your needs. While they are more expensive, they have great green features, which are energy efficient and will save you money over time.

Among some consumers, there are occasional complaints about the water temperature being colder than usual. This is always something that will vary by home but this topic is covered in our review. Another consideration is the high running costs compared to some other brands. The Rheem tankless water heater is packaged with a number of features not available on other models. Features such as power-driven fans and flame-sensing technology can help to lower your energy bill. The Rheem RTE 13 Electric Tankless Water Heater provides a quick and easy installation, requires no venting and no electricity to pump water. The tankless water heaters offer an endless supply of hot water on demand.

What brand of tankless water heater is the most reliable?

Reliability is the number one factor that we weighed when reviewing this industry. The chart you see is the result of reading through more than 500 customer reviews, visiting forum sites, speaking with experts, and checking out major shopping sites like Amazon to find the brand that most customers found to be the most reliable.

This result echoed the other results we found as well. While we saw some competitors claim to be the most reliable, we didn't really find much proof of that conclusion. However, we did find that when people had problems, they were much quicker to name one of these brands than any others.

Overall, it seems that Rheem, with its mix of quality, customer service, and great reputation for reliability, is the best choice in tankless water heaters. If you're shopping for a new water heater, this is the one we recommend you choose.

What is the downside of a tankless water heater?

The primary downside of a tankless water heater is the upfront cost. Tankless water heaters aren't all that expensive, at least the ones we liked, but it still might be expensive for some people. Installation can also be an issue since tankless water heaters usually require more piping and parts than tank-based heaters.

Finally, there is the issue of cold water pressure. If you have an old-school water heater, then it might have a pressure regulator that decreases water pressure as a way of conserving hot water and energy. If you turn down the temperature on your current water heater, then you might be turning down the pressure as well. More powerful pressure is important with tankless water heaters, so make sure you have a good, strong water source.

How long do Rheem water heaters last?

This may be a question that is specific to your usage pattern. If you are living in a temperate region, you probably don't need a large water heater. If you are living in a very warm region you might want a tank larger than the 20 gallons of the unit we cover here.

The Rheem system we are featuring here is a basic model on the higher end of the market. You can purchase this model either in a 30-gallon tank size or a 50-gallon tank size. You can also purchase this model in an electric format or a gas format. We cover the gas format here as we feel it is the most common.

The heaters we cover here are rated to heat water at 6.1 gallons per minute. When the tank is full, the tank can handle about 105 gallons worth of water.

Conclusion

We hope this guide will help you get the best Rheem tankless water heaters for your money, based on your needs. We've based our ratings on several factors, including power, heat output, warranty, cost, quality, and safety. Visit the links on the product name for more details on individuals items. Our best recommendation is the Rheem RTGH-95DVLN dual-type tankless water heater.

Our Recommendation

NameCategoryProduct
Rheem 240V Heating Chamber RTEX-13 Residential Tankless Water HeaterBest OverallRheem 240V Heating Chamber RTEX-13 Residential Tankless Water Heater
Rheem RTEX-18 18kW 240V Electric Tankless Water HeaterBudget PickRheem RTEX-18 18kW 240V Electric Tankless Water Heater
Rheem RTG-84XLN 8.4 GPM Low NOx Outdoor Tankless Natural Gas Water HeaterUpgrade PickRheem RTG-84XLN 8.4 GPM Low NOx Outdoor Tankless Natural Gas Water Heater