Rheem Tankless Gas Water Heaters

If you’ve been investigating good tankless water heaters, then no doubt you have heard about Rheem. Across the plumbing and mechanical industry, builders and installers alike are very familiar with Rheem tankless water heaters, and with an increasing number of DIY homeowners, the brand is well positioned to gain even more fame.

Rheem is the largest manufacturer of water heaters in the United States. In fact, the brand has such good reach that in 2015, Builder magazine awarded Rheem the top position for brand familiarity in the water heater category.

Founded in California by the Rheem brothers in 1930, the company began by manufacturing steel drums and water heaters. After purchasing several local steel and manufacturing companies, it expanded water heater production and steel container manufacturing into Australia in 1936. During World War II, the company shifted most of its manufacturing to the wartime production of aircraft and ship parts. In 1956, Rheem introduced central air conditioning and heating for the home, and in 1959 purchased Ruud Manufacturing, which the company still markets today. The company has been a subsidiary of Paloma Industries, a gas appliance company based in Japan, since 1988.

To help you with your search for the best tankless water heater to fit your needs, we have pulled together some Rheem tankless water heater reviews, many of which are current bestsellers.

Rheem RTG-84XLP Outdoor Tankless Propane Water Heater

If you already have a propane energy source, you will not be disappointed with the Rheem RTG-84XLP. Offering an impressive 8.4 GPM to customers will go a long way in Rheem’s effort to produce great products with excellent features. As expected, it pushes this propane tankless water heater into the mid-high price range.

The RTG-84XLP has an energy factor of 0.82 and has a built-in electric blower, so it’s only for outdoor installation, and would also work well in high altitudes (up to 9,840 feet with no chip needed). Something else that makes this unit stand out is that it offers freeze protection at temperatures as low as -30 degrees F. Always make sure to insulate your intake and output pipes to prevent any freeze issues as well.

Another feature worth noting is that both the water and gas line connections for the RTG-84XLP are ¾-inch instead of ½-inch. Be sure this matches your current allowances before you install. It has an electric ignition, which requires an outlet, and you get 10 feet of thermostat wire included. As an added convenience, Rheem includes a remote control so you don’t have to trek outside to adjust temperature.

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Rheem RTG-95XLP Outdoor Tankless Propane Water Heater

If you have a large three or four bathroom home with four or more occupants and you’re already using propane as a fuel source, the RTG-95XLP might be the best tankless water heater for you. It has all the features of the RTG-84XLP, with more power and a higher GPM flow.

A flow rate of 9.5 GPM is one of the highest GPMs in our listing of the top tankless water heaters. As expected, it means this propane tankless water heater falls in the mid-high price range. However, it is currently priced the same as the RTG-84XLP, so for the same amount you get a better-performing heater—take advantage of this great deal before the price changes!

The RTG-95XLP has a BTU range from 11,000 to 199,900 BTU. For this outdoor unit, the default output temperature is 120 degrees F, but it can be raised up to 140 degrees F with a simple change on the remote control (included with the unit so you don’t have to trudge outside to adjust the temperature). Most competitor units only get up to 120 degrees F,  so if you prefer hotter water for your laundry and dishwashing, this unit will perform well.

Another feature of note: both the water and gas line connections for the RTG-95XLP are ¾-inch instead of ½-inch. Be sure this matches your current allowances before you start installation. It has an electric ignition, which requires an outlet, and 10 feet of thermostat wire is included.

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Rheem RTE 13 Electric Tankless Water Heater

This tiny little electric unit will amaze you with what it can do. Do not let its small size (9 x 10 x 5 inches) or low price deceive you! The RTE 13 would be best for a single-occupant home or a small office or studio with modest hot water needs.

You can expect the RTE 13 to pull about 240 volts and use about 13 KW of energy at its max temperature. It offers a 4.0 GPM maximum flow rate, so don’t expect it to give hot water to multiple water points simultaneously. Its low price point is a big draw for users, but don’t forget about the installation costs of copper piping and the electric parts for the panel hookup. You’ll need to safely run a 60-amp service for the RTE 13.

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Rheem RTE 9 Electric Tankless Water Heater

At the smallest electric size tankless water heater on our Rheem tankless water heater review, it’s also the lowest priced unit. The RTE 9 is a great little unit to install for point-of-use heating near a distant bathroom, by your kitchen sink or clothes washer, or even in your RV or boat.

You can expect the RTE 9 to pull about 240 volts and use about 9 KW of energy if it’s at its max temperature. You will need to dedicate 40 amps in the panel for the electrical installation of the RTE 9. The plumbing connections are standard ½-inch pipe fittings.

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Rheem RTGH-95XLN Natural Gas Outdoor Condensing Tankless Water Heater

The RTGH-95XLN is one of the most efficient Rheem tankless water heaters available, with an energy factor of 0.94. This EF also means the RTGH-95XLN is Energy-Star certified. Because it’s a condensing unit, it has a stainless steel heat exchanger, versus most other units that use a copper exchanger. You’re definitely getting a great flow rate with this unit at 9.5 GPM. All of these factors place this model at the top of the price range.

It does have a two-pipe direct vent system designed for PVC pipe, for up to 35 feet of three-foot PVC pipe or five feet of two-foot PVC pipe. The RTGH-95XLN requires an installer to hardwire an electrical connection for the starter, as there’s no pilot light.

Rheem also boasts about this model’s 0.26 GPM minimum flow rate, claiming that to be the best in the industry, and a 0.40 GPM minimum activation flow rate. This is great for customers who sometimes want a light hot water stream for washing dishes or hands. Rheem’s water heaters include a 12-year limited heat exchanger warranty, and a five-year limited parts warranty.

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Rheem RTG-64XLN Outdoor Tankless Natural Gas Water Heater

Rheem has done a fine job with the 6.4 GPM output for homes that have lower-than-average hot water needs. The Rheem RTG-64XLN is at the middle of the price range due to its flow rate of 6.4 GPM and its natural gas energy source.

Engineered to be installed outdoors for mild or temperate climates, this natural gas tankless water heater also comes with a remote temperature controller. So, thankfully, you will not have to walk outside to adjust the temperature manually. This line of Rheem heaters have low-NOx emissions, and a 0.82 energy factor for efficiency. Count on the Rheem RTG-64XLN for standard ½-inch gas line compatibility for easy hookup during outdoor installation.

RTG units like the Rheem RTG-64XLN feature a water-saving setting that reduces the water flow in the pipes until the heater can reach your ideal temperature, and will then ramp up and increase to your desired flow rate. The RTG-64XLN offers an impressive minimum flow rate of 0.26 GPM, which is standard in the RTG line and a first for the tankless water heater industry. Rheem has also engineered a minimum activation flow rate of 0.40 GPM, offering instant hot water even in those low-demand hot water situations.

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Rheem RTG-64XLP Outdoor Tankless Propane Water Heater

You won’t find many differences between this unit and the RTG-64XLN, beyond the energy source required here. With a 6.4 GPM output, this RTG-64XLP is best for homes that have a lower-to-average level of hot water needs. Find it in the mid-low end of the price range due to its flow rate of 6.4 GPM and its propane energy source.

Engineered to be installed outdoors for mild or temperate climates, this propane tankless water heater also comes with a remote temperature controller. This line of Rheem heaters has low-NOx emissions, and it has a 0.82 energy factor for efficiency. You can count on the Rheem RTG-64XLP for standard ½-inch gas line compatibility for easy hookup in outdoor installations.

RTG units like the Rheem RTG-64XLP feature a water-saving setting that reduces the water flow in the pipes until the heater can reach your ideal temperature, and will then ramp up to your desired flow rate. RTG-64XLP offers an impressive minimum flow rate of 0.26 GPM, which is standard in the RTG line and a first for the tankless water heater industry. Rheem has also engineered a minimum activation flow rate of 0.40 GPM, offering instant hot water even in those low-demand situations.

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Rheem RTG-84XLN Outdoor Tankless Natural Gas Water Heater

The Rheem RTG-84XLN falls in the mid-high end of the price range due to its 8.4 GPM water flow and its natural gas energy source. Engineered to be installed outdoors for mild or temperate climates, this unit comes with a remote temperature controller.

Rheem offers a super line of mid-range tankless heaters, with a water-saving setting that reduces the water flow in the pipes until the heater can reach your ideal temperature. This unit is also part of Rheem’s low-NOx emission line, and offers a 0.82 energy factor thanks to its all-copper heat exchanger.

Rheem RTGH-84XLN Outdoor Natural Gas Condensing Tankless Water Heater

This model is a high-efficiency condensing unit, so you get an EF of 0.94 instead of the 0.82 typical of mid-efficiency Rheem tankless water heaters. This EF also means the RTGH-84XLN is Energy-Star certified.

Because it’s a condensing unit, it has a stainless steel heat exchanger, versus the typical copper heating element. Another perk of this outdoor natural gas tankless heater is its 3-inch/5-inch concentric vent system with integrated condensate collector, which saves you the headache of installing drain lines like condensing indoor units usually need.

The Rheem RTGH-84XLN fits in the middle of the price range due to its 8.4 GPM water flow and its natural gas energy source. Engineered to be installed outdoors for mild or temperate climates, this natural gas tankless water heater does also come with a remote temperature controller.

Conclusion

Most users will be happy to purchase a Rheem tankless water heater. The brand’s history and customer service experience provide the trust that consumers demand from appliance manufacturers these days. More than anything, please do your homework before purchasing and make sure that the unit you buy is the right fit for your needs—not only that you have the electrical capacity, but the correct size gas line hookup. It would also be a great idea to make sure your region’s groundwater temperature will fit with the water temperature rise you are expecting from a unit.