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In our Rheem gas water heater review, we’ll look in depth at the Rheem model RTG-64DVLP tankless water heater and see how it measures up against similar units. Tankless water heaters are unique and their popularity is exploding.
Energy conscious people have long considered on-demand water heating an efficient means to deliver an endless supply of hot water into their homes, without the unnecessary waste of energy found with use of conventional water heaters.
What Is the Rheem Gas Water Heater?
A majority of people in the United States associate water heaters with large tanks of hot water taking up space in a basement or closet. This water heater keeps water hot and ready for use whenever it’s needed. The Rheem gas water heater heats water on demand, only when you need it, and doesn’t store water.
The Rheem tankless water heater responds instantly when hot water is requested. The heater uses either electricity or gas to power its heater. They’re powerful heaters and instantly heat water as it passes through the unit. As with a conventional water heater, it directly relates hot water delivery time to the distance between the heater and faucet.
A reason for their popularity is their efficiency. A tankless water heater turns on only when a hot water faucet is opened, and turns off when it’s closed. Compare that to storing and heating hot water regardless if it’s needed. Tankless water heaters don’t waste energy, save money, and you’ll always have a never-ending supply of hot water.
The Rheem RTG series which includes the model in our Rheem gas water heater review is a direct vent propane style water heater. They feature ultra-low NOx (oxides of nitrogen) which is an atmospheric pollutant.
They rate RTG models as mid-efficiency gas water heaters specifically designed for homes with one or two bathrooms. They rate their efficiency at 82% thanks to its stainless steel condensing heat exchanger.
The RTG-64 includes self-diagnostics, helpful for troubleshooting problems quickly, and a built-in electric blower. It’s rated at 6.4 gallons per minute at a 35 degree Fahrenheit rise, and 5.6 gallons per minute at a 45 degree Fahrenheit rise. The heater produces 11,000 – 150,000 max BTU output.
The RTG-64DVLP price falls into the range of $750 – $1000, but prices vary by region and availability. The unit is available from retailers such as The Home Depot and online at the Plumber’s Crib.
How It Compares
We picked a few similar products available on the market to see how they compare.
Rheem Gas Water Heater
- Minimum flow rate of .26 gpm, .40 gpm minimum activation flow rate, 180,000 BTU
- Includes UMC-117 remote control and 10-feet of thermostat wire
- Vent termination kit required
- Design Quality
This unit surpasses many expectations from other tankless water heaters users. Aside from an occasional drop in the quantity of hot water caused by too many faucets, problems didn’t arise during our Rheem gas water heater review. We consistently had hot water flowing, with little change in temperature during our tests. We noticed a slight degradation in volume when seven more faucets were turned on besides four already in operation.
Rheem’s RTG efficiency is a big talking point in our review because the unit shuts down immediately after demand is gone. In effect, its on again, off again operation removes the waste and added cost for fuel (gas or electric). A gas water heater capable of using energy only when needed, and in small amounts, impressed us.
Users rarely complain about the unit’s construction, or its user-friendliness. We like the digital display and self-diagnostics. If the unit fails, it’s reassuring to know we could troubleshoot the problem quickly, and bring it to a successful end. Customer support is responsive, and knowledgeable, giving us added confidence of a quick resolution to any problem.
In our Rheem gas water heater review, our research shows they’re committed to a long-lasting product, and prove it in wording their warranties. Depending on model variations, etc, Rheem warrants all their tanks from leaks, and offer replacement if a leak occurs during the warranty period. We give them high marks for standing behind their products.
- Energy savings
- Low NOx emission
- Space savings
- Easy to install
- Additional faucets require size upgrade
- Requires dedicated double-wall stainless vent
- Some parts are unavailable
AO Smith GPHE-50 Water Heater
- 90-Percent thermal efficiency
- Sidewall and vertical vent options
The AO Smith GPHE-50 gas water heater is designed for normal use by up to a four-person household. We included this model in our Rheem gas water heater review for comparison. We like the thermal efficiency of 90% and its claim of 3 gallons of hot water per minute. The high efficiency adds to energy savings and lower operating costs. A 50-gallon water heater is normally a taller than average unit, and this model is slightly taller than average but narrower to take up less floor space. Its 27-inch diameter body allows installation in tighter spaces without sacrificing scarce storage area.
This AO Smith water heater operates similar to standard models and relies on its gas-fueled burner at the bottom of the tank. The spiral heat exchanger is located in the middle of the tank for efficient heat distribution and earns a 96% thermal efficiency rating, higher than standard models at around 80% efficiency. We like the easy-to-use Intelli-Vent Gas Control for temperature and system adjustments.
- Design Quality
During our tests, we experienced varying availability and temperature of hot water during purposely heavy usage. We had two showers running, and two bathtubs filling with hot water. Faucets open fully didn’t change our tests. We noticed a lag in start-up of the powered vent twice during testing, but that issue disappeared quickly, presumably from our rigorous routine of demanding hot water for long periods (30 minutes).
Thanks to its 96% thermal efficiency rating, and spiral heat exchanger performing exceptionally well, we experienced satisfactory temperature variations of about 3 degrees Fahrenheit, which could fall into the margin of error of our instruments. However, our stringent tests showed a drop-off of hot water availability, but not enough to affect our rating.
AO Smith builds a quality product, and it shows in the creativity in their design of this water heater. The powered vent with side and vertical choices is a definite plus and adds to its installation options. We’re impressed with this unit’s efficiency ratings in the high 90s, compared to standard units with notably lower ratings.
AO Smith provides a 6-year limited tank and parts warranty, but it does not cover labor.
- Powered vent
- 90-Percent thermal efficiency
- Sidewall and vertical vent options
- Includes side taps for simple installation
- Reports of warranty issues
Rinnai RUC98iN Ultra Series Natural Gas Tankless Water Heater
- INDOOR installation only. Fuel Type: NATURAL GAS.
- Concentric or PVC venting option
- Up to 0.96 Energy Factor/Up to 0.92 Uniform Energy Factor
Next up in our Rheem gas water heater review is the Rinnai RUC98iN. This is an indoor gas tankless water heater for either residential or commercial use. Fuel requirements are propane or natural gas and offer multiple venting options. A handy feature is a control featuring a digital display with power, temperature, and gas control buttons. It also has a lockout function for temperature settings.
Venting for this unit are concentric or twin-pipe PVC, and it complies with nitrogen oxide emission standards. We noticed larger gas and water supply fittings required than what is found on similar tankless designs. It’s obvious this unit is heavier and larger than most designs in this category, but it’s more powerful than most, too.
This water heater’s flow rate is a surprising 0.26 to 9.8 gallons per minute and activates at a flow rate of 0.4 gallons per minute. This is a pricey unit with installation and warranty restrictions, but makes up for any inconvenience with its ability to provide steady hot water in homes with multiple bathrooms and faucets. Its temperature ratings include a heating capacity up to 140 degrees Fahrenheit, and to 140 degrees Fahrenheit in its commercial version.
- Design Quality
The RUC98iN boasts a mega-burner generating up to 199,000 BTUs, adjustable down to 15,200 BTUs. The RUC models feature an eco-friendly burner and its modulating burner allows it power down to a low of 15,200 BTUs. Temperatures are controlled by a dip switch or the control built into the front panel. If a failure occurs, error codes are accessible from the control to assist troubleshooting. An external pump permits fast hot water delivery and recirculation when necessary.
The unit features a maximum energy factor of 0.96 and is Energy Star compliant and designed for either natural or propane gas. We like the flexible venting options with direct venting using concentric PP or twin-pipe PVC, with no venting adapters needed. Its green technology and ultra-low NOx meets emission standards.
We feel the best model from Rinnai is the RUC98iN directly related to its high energy factor and powerful burner. Its constant and hardly varying water flow delivery makes this unit stand apart from many in its category. Also, its compact size allows for versatile installation options.
Rinnai provides a 12-year warranty on the heat exchanger and a five-year warranty on parts.
- Easy to adjust settings
- Powerful and efficient
- Residential and commercial versions
- Difficult installation
- Service provided by authorized personnel
- Heavy and bulky
Takagi T-KJr2-IN-NG Indoor Tankless Water Heater
- Indoor installation only; Direct-vent conversion optional
- 11,000 - 190,000 BTU/hr
- 0.82 energy factor
The last product in our Rheem gas water heater review is the Takagi T-KJr2-IN-NG natural gas indoor tankless water heater. The most impressive feature about this model is not a feature at all. It’s the customer service. They care about their customers and the customer’s needs.
Our best impression of this model is the design and functionality. Once installed, it works flawlessly, albeit struggling to keep up with a high demand for hot water. If the water supply is kept constant and doesn’t overwhelm the heater, the unit performs well. In larger homes, higher water pressure may limit its ability to supply constant hot water.
- Design Quality
While the unit is budget priced, its performance is close to that of a standard 40-gallon water heater. Takagi uses thermistors for temperature sensing and an AFR (air-fuel ratio) sensor that monitors efficiency and helps reduce emissions. The unit also protects itself from freezing and shuts down if overheating occurs. In case of a failure, users can view error codes to assist troubleshooting efforts.
Output from this unit ranges between 19,500 – 140,000 BTUs, and they rate the flow at 6.6 gallons per minute with a 0.5 GPM activation rate. We found the unit capable of supporting radiant and baseboard heating applications. For most efficient operation, Takagi requires a certified installer perform installation for best results, and to activate and preserve the warranty.
The unit is constructed with essential features, and installation is simple. Venting is required, but can be horizontal or vertical, but prevent voiding the warranty, only a certified Takagi installer is allowed to perform this work.
Takagi provides a 15-year parts warranty on the heat exchanger, five years on parts, and one year reimbursed labor for a single-family residence.
- Customer service
- Installation by Takagi required
- Meant for small homes
- Tricky venting installation
Rheem Gas Water Heater Review | Conclusion
In our Rheem gas water heater review, we found the Rheem RTG-64DVLP gas water heater efficient, capable, and affordable. It passed our tests with expected results and we rated each finding accordingly. We will end our Rheem gas water heater review by awarding model RTG-64DVLP 4.8 stars out of 5.0 possible.