Frequently Asked Questions About Tankless Water Heaters - Rheem Water Heaters

Tankless Water Heaters Frequently Asked Questions

1)What is a tankless water heater?
Tankless water heaters are compact in size and provide a steady flow of hot water for as long as you need it. Rheem tankless gas water heaters are more energy efficient than conventional water heaters, because the tankless models eliminate the need for re-heating stored water.
2) How does the Rheem tankless water heater work?
A conventional tank-style water heater stores hot water, and heats the water 24/7, whether you use it or not. The new generation Tankless Technology Water Heater from Rheem only heats water on demand. When the faucet is opened, the water flows through the Rheem Tankless Water Heater, which heats it to the temperature you've digitally set. When the faucet is closed, the Rheem Tankless Water Heater senses the command, and goes to standby mode.
3) Can it be installed in the same place my old hot water heater was installed?
As long as enough combustion air is provided, Rheem tankless water heaters can be installed in a utility room, garage, basement, attic, or placed on an outside wall. Plus, they can be installed in locations where a storage water heater may not fit. The Digital Temperature Controller can be mounted in any room.
4) What is the Energy Factor for the Rheem Tankless water heaters?
Answer: Rheem Mid-Efficiency RTG-64, RTG-84, and RTG-95 heaters feature an Energy Factor of .82  Rheem High Efficiency Condensing models RTGH-84 and RTGH-95, feature an Energy Factor of .94.
5) Does this mean tankless water heaters have lower operating costs?
A higher EF is only one of many reasons why tankless water heaters cost less to operate. A Rheem tankless water heater has no standing pilot light, no stand by loss, and the burners modulate to maintain maximum efficiency.
6) How do I ensure that I select a tankless water heater in the appropriate size for my home?
It's as easy as 1-2-3! If your home has only one bathroom, a Rheem tankless RTG-64 series water heater provides an ample supply of continuous hot water for your needs. If your home has two bathrooms, a Rheem RTG-84 series water heater provides an ample supply of continuous hot water for your needs. If your home has three bathrooms, choose a Rheem RTG95 series, which can supply up to 3 showers simultaneously. Homeowners with 3 or more bathrooms and/or large volume multi-head showers should consider linking (manifolding) 2, 3, or more of our tankless water heaters together.
7) Does Rheem offer customer service for their tankless water heaters?
Yes! Rheem Customer Service is available 7 days a week/7 a.m. to 7 p.m. Central Time. The professional staff provides fast, reliable service. Customer service options are available, please call 1-866-720-2076 or visit
8) Can you adjust the water heater setpoint temperature setting in 1 degree increments?
No, the minimum temperature adjustment for RTG series waters heaters is a 2 degree increments from 100 F up to 120 F and 5 F increments from 120 F to 140 F.
9) What safety device is used to prevent overheat failure of the heat exchanger?
An Over Heat Limiting Film wrap is wrapped around the entire heat exchanger. This monitors the temperature of the heat exchanger and will shut the unit down if it exceeds a safe temperature. This is an exclusive feature of the Rheem tankless water heaters.
10) What is the minimum clearance on the back, sides, top, bottom, and front of the water heaters?
0" back, 1/2" sides, 12" top, 12" bottom, and 12" front.
11) What does the sensing burner do?
The sensing burner is a device that detects incomplete combustion during operation of the water heater. If incomplete combustion is detected, the water heater corrects the problem to provide clean, efficient water heater operation at all times. This is an exclusive feature of the Rheem tankless water heaters.
12) Is there a standing pilot?
No, the direct ignition sends a spark to the main burner when hot water flow is detected. This feature improves the energy efficiency of the water heater.
13) Can I convert the water heater from LP to natural gas or natural gas to LP?
No, these units can not be converted from one fuel source to another.
14) Where in my home can I install a Rheem tankless water heater?
The RTG-64DV, RTG-84DV, and RTG95DV may be installed in all locations, including bedrooms and bathrooms. These units obtain combustion air from the outdoors. These models are not designed for use in mobile homes. The RTG-64X, RTG-84X, and RTG-95X outdoor models are for outdoor installations only, and are a great alternative if your climate is appropriate. This saves space and the cost of venting.
15) What are some reasons to use a tankless water heater over a standard storage-type water heater?
Tankless water heaters can provide a continuous supply of hot water, while a tank will run out of hot water. Tankless products also have a longer life; lower operating costs, precise delivery temperature, and can be installed in many locations where a storage water heater may not fit.
16) How much can I expect to save on my monthly bill if I install a tankless water heater?
Test results have shown that a tankless gas water heater costs about 40% less to operate than an electric water heater, and about 30% less than a natural gas water heater.
17) How much more do they cost to purchase?
Generally, a tankless water heater will cost about 2 to 2-1/2 times as much as a standard water heater to purchase and install. Keep in mind that in addition to lower operating costs, useable square footage is gained by choosing tankless!