Answers to Common Questions

1. What is a tankless water heater?
2. How does the Rheem tankless water heater work?
3. Can it be installed in the same place my old hot water heater was installed?
4. Are tankless water heaters energy efficient?
5. Is a tankless water heater more energy efficient than a tank?
6. What is the Energy Factor for the RTG-42 series water heaters?
7. What is the Energy Factor for the RTG-53, RTG-74 and 199 series water heaters?
8. Does this mean tankless water heaters have lower operating costs?
9. How do I ensure that I select a tankless water heater in the appropriate size for my home?
10. Can I link multiple tankless heaters together for more gallons per minute?
11. Does Rheem offer customer service for their tankless water heaters?
12. What is the minimum water flow rate required for the tankless water heater to ignite?
13. What type of exhaust venting do these products require?
14. Can you adjust the water heater setpoint temperature setting in 1 degree increments?
15. What is tempature rise and flow rate?
16. What safety device is used to prevent overheat failure of the heat exchanger?
17. What is the minimum clearance on the back, sides, top, bottom, and front of the water heaters?
18. What does the sensing burner do?
19. How do I calculate if I have enough combustible air?
20. Is there a standing pilot?
21. Can the water heater be installed at elevations that are 5,000 or 6,000 feet above sea level?
22. Can I convert the water heater from LP to natural gas or natural gas to LP?
23. Where in my home can I install a Rheem tankless water heater?
24. What are some reasons to use a tankless water heater over a standard storage-type water heater?
25. How much can I expect to save on my monthly bill if I install a tankless water heater?

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.

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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.

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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.

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4. Are tankless water heaters energy efficient?

   Yes, tankless water heaters are very energy efficient. The Energy Factor, EF, of all Rheem tankless water heaters is over .81. By comparison, a standard tank type water heater has an EF of around .62, so you can see that they are inherently more efficient than a storage type water heater.

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5. Is a tankless water heater more energy efficient than a tank?

   Rheem tankless gas water heaters are more energy efficient than conventional water heaters, because they eliminate the need to maintain a large supply of heated water. A Rheem tankless water heater operates only when hot water is needed. Regardless of whether you currently have a conventional electric or gas water heater, the Rheem tankless will save money on your energy bills. back to top
   

6. What is the Energy Factor for the RTG-42 series water heaters?

   Answer: 0.83

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7. What is the Energy Factor for the RTG-53, RTG-74 and 199 series water heaters?

   Answer: 0.82

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8. 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.

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9. 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-42 series water heater provides an ample supply of continuous hot water for your needs. If your home has two bathrooms, a Rheem RTG-53 series water heater provides an ample supply of continuous hot water for your needs. If your home has three bathrooms, choose a Rheem RTG-74 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 (via the EZ-Link cable or via manifolding) 2, 3, or more like tankless water heaters together.

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10. Can I link multiple tankless heaters together for more gallons per minute?

    Yes, multiple units can be linked together with either the EZ-Link cable or the manifold. You must link like models. For example, you can link an RTG-53 with another RTG-53. You can not link an RTG-53 with an RTG-74.

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11. 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. Their professional staff provides fast, reliable service. Customer service options are available, please call Rheem directly at 1-866-720-2076. If you have a question pertaining to your order you can call us at 1-800-714-9833.

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12. What is the minimum water flow rate required for the tankless water heater to ignite?

    All Rheem tankless water heaters require a minimum flow rate of .66 GPM to ignite the burner. Too little flow will not activate the main burner.

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13. What type of exhaust venting do these products require?

    The venting must be Category III, Stainless steel, and it applies to the adapter, the vent pipe, all elbows, and terminal vent. This is important because the flue gases and by-products of combustion can cause condensation. Stainless steel will not deteriorate like type B venting under these conditions. The RTG-53X, RTG-74X and GT-199X outdoor models do not require any venting materials. Always consult the Use and Care Manual provided with the water heater for detailed installation and venting instructions.

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14. Can you adjust the water heater setpoint temperature setting in 1 degree increments?

    No, the minimum temperature adjustment for RTG series waters heaters is 2° increments from 100°F up to 120°F and 5°F increments from 120°F to 140°F. The minimum temperature adjustment for GT series water heaters is 2° increments from 100°F up to 120°F and 5°F increments from 120°F up to 180°F.

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15. What is tempature rise and flow rate?

    Temperature rise is based on how much the incoming water must be raised to meet the desired output temperature. Flow rate is how many gallons per minute (gpm) an application will produce at a given temperature rise.

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16. 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.

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17. 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, 12" front, and 2" vent (for indoor models only).

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18. 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.

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19. How do I calculate if I have enough combustible air?

    Multiply the Length by the Width by the Height of the room you're installing your tankless water heater in and add up the total BTUs that will be used (include the furnace if present, etc)

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20. 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.

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21. Can the water heater be installed at elevations that are 5,000 or 6,000 feet above sea level?

    All Rheem tankless water heaters can be programmed to operate at elevations up to 9,840 feet. Optional programming chips are available for elevations greater than 3,280 feet above sea level. One programming chip is available for elevations between 3,280 - 6,560 feet, and a second optional chip is available for elevations between 6,560 - 9840 feet. The chips install on the water heater circuit board (PCB) in a matter of minutes and are available from the Rheem Service Parts Department. This again is an exclusive Rheem feature and is designed to insure proper combustion at these higher altitudes.

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22. 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.

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23. Where in my home can I install a Rheem tankless water heater?

    The RTG-42PV, RTG-74PV, and GT-199PV indoor units are very versatile, and can be installed in a utility room, a garage, a basement, or an attic as long as enough combustion air is provided. As with any appliance, consult local codes and the manufacturer Use and Care manual prior to choosing the site for installation. They may not be installed in a bedroom or bathroom, and are not designed for use in mobile homes. The RTG-53DV, RTG-74DV, and GT-199DV 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-74X and GT-199X 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.

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24. 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.

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25. 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.

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