When you’re looking for seemingly unlimited on-demand hot water, a tankless water heater is the way to go. Easy to install and smaller than a water heater with a tank, these workhorses can handle multiple luxuriously hot showers and still run a dishwasher. But when selecting between two top brands — Rinnai and Rheem — which comes out on top?
Rinnai tankless water heaters are expensive but come with reliable performance. Rheem has a better variety of sizes and styles to suit a wider range of needs.
Rinnai has been in business for over 100 years. Its tankless water heaters are known for their innovative designs, high standards in production and solid performance.
Its energy-efficient water heaters come in a high-efficiency tankless water heating series and a super-high-efficiency series. Most carry Energy Star certifications.
Rinnai prides itself on creating products that are trustworthy and long-lasting.
Rinnai tankless water heaters are known for features that set them apart from other brands.
There are a few downsides to consider. The first is price. Rinnai tankless heaters cost more than other brands.
This brand may also require specialized skills for installation and can cost more in that area, too. And professional installation is required. Doing it yourself may void the warranty.
Some customers report that their Rinnai heater seems to run constantly to maintain the water temperature.
Rinnai RU199iN Indoor Condensing Tankless Hot Water Heater
This model circulates 11 gallons per minute and comes with a 15-year warranty on the heat exchanger. It is connected to Wi-Fi and can support up to seven appliances. It’s great for larger households.
Sold by Amazon
Rinnai RL94EN Outdoor Tankless Hot Water Heater
With a 12-year heat exchanger warranty and included isolation valves, the additional cost of this unit pays for itself. It heats almost 10 gallons of water per minute and can be programmed to have hot water ready instantly.
Sold by Amazon
Rinnai RUCS65IP Indoor Tankless Hot Water Heater
Hook this tankless water heater up to propane instead of natural gas for 6.5 gallons of water per minute and hot water on demand. It supports smaller households, is more affordably priced, and does not require a natural gas line for installation.
Sold by Amazon
Rheem was founded in California in the 1920s. Today, the company makes water heaters that fit every size household and level of use. It offers two lines of heaters.
Rheem’s focus is providing affordable, reliable options for households both large and small.
Rheem offers tankless water heaters that can be powered by natural gas, propane or electricity. Other features include:
These features come at a more affordable price than other brands, and they also have three types to choose from.
Rheem tankless water heaters may not be as durable as other brands. The lower price means that some parts are made of plastic that can break easily with normal use.
Many customers also had issues with Rheem’s customer service.
Rheem RTGH-95DVLN Indoor Tankless Water Heater
This delivers 9.5 gallons of water per minute and has the option to connect two units to increase that capacity. It has freeze protection and is easy to install, directly venting clear PVC pipe. It comes with a 12-year warranty on the heat exchanger.
Sold by Wayfair
Rheem RTEX-24 24kW 240V Electric Tankless Water Heater
Although not Energy Star-certified, this model converts almost 100% of the electricity it uses into heated water. It uses three copper immersion heating elements to adjust the temperature using as little electricity as possible. It's less expensive to install and works well for running multiple appliances at once.
Sold by Amazon
Rheem Mid-Efficiency Outdoor Tankless Water Heater
Use this on-demand natural gas-powered heater in temperatures as cold as minus 30 degrees. It delivers 8.4 gallons of hot water per minute and has a remote electronic thermostat that can be adjusted to temperatures from 85 to 140 degrees.
Sold by Amazon and Home Depot
Although Rinnai has a solid design and top-rated performance, for more options and a more affordable price, a Rheem tankless water heater is the better bet.
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Suzannah Kolbeck writes for BestReviews. BestReviews has helped millions of consumers simplify their purchasing decisions, saving them time and money.