1. What is a tankless water heater?

Tankless water heating systems are revolutionizing the way modern homes meet their water heating needs. These compact units can produce and supply endless streams of hot water to multiple outlets at once without any fluctuation in temperature.

2. What type of fuel do Rinnai tankless water heaters use?

All Rinnai tankless units are either LP or natural gas fired. This is because clean burning gas systems can be designed to provide hot water to a large household at the highest efficiencies available.

3. Does Rinnai make electric tankless units?

No. There are electric tankless units available, but they have two distinct problems:

First, the cost of electricity is, on average, significantly higher than LP or natural gas. The operating cost of electric tankless units tend to be much higher.

Second, electric tankless water heaters can only produce a relatively small amount of hot water. This is because they require a large amount of electrical current to produce a significant amount of hot water. For example, in order to have the same capacity as our smallest unit you would need to provide about 120 amps of power to an electric tankless unit. This represents well over half the amperage capacity of a typical home and 5 times the amperage of a typical central air conditioning system.

4. How does a Rinnai tankless system work?

Click here to view our operation animation

Conventional water tanks heat and store hot water around the clock. Because of this you are heating and re-heating water, and constantly losing energy up your vent and through the walls of the tank. A tankless water heater only comes on when you start to use hot water, and immediately shuts off when you are done, so you are not wasting energy when you do not need hot water.

Tankless water heaters have much more effective heat exchanger and burner systems than conventional tanks. This allows you to utilize a much higher percentage of your energy dollar rather than wasting it up the vent stack of a conventional tank water heater.

5. Why are Rinnai tankless water heaters so efficient?

We have a huge amount of experience installing Rinnai Tankless water heaters in Austin, TX. Rinnai has decades of experience in designing and building tankless water heaters throughout the world. Rinnai's precisely designed components are microprocessor controlled to maximize efficiency. They do not store hot water, waste energy by using a conventional chimney, and have electronic ignition so there is no wasteful pilot flame.

6. What is the Energy Factor of Rinnai tankless heaters?

Water heaters are performance rated by the US Department of Energy. The performance measure that they have developed is the Energy Factor (EF). The higher the Energy Factor the more efficient the water heating system is. Most gas fired water tanks have an Energy Factor of only about .62. If you have an existing older tank it is likely to be .55 or less. Rinnai tankless units all have Energy Factors of .80 or greater so they are much more efficient than tanks. This efficiency makes Rinnai the best choice in Austin Texas.

7. Does a higher Energy Factor mean that I will always have lower operating costs?

Click here to use our operating cost calculator. You can enter the details of your application and we will calculate what a Rinnai can do for you in dollars and cents.

Given a specific fuel and a specific number of gallons of hot water used, the higher the EF, the lower the operating cost.

Some people do not experience as much savings with tankless because with tankless there is no longer an artificial barrier to hot water use. With conventional tanks you will run out of hot water after a period of use, but with Rinnai tankless, this will not happen. In some homes this increases the gallons of hot water used, but its great to have all the hot water you need, when you need it.

Given different fuels EF may not accurately predict energy cost. For instance a Rinnai tankless unit with an EF of .85 will always have far lower operating cost than an electric tank with an EF of .90 (given current national average fuel costs.)

8. Do Rinnai Tankless water heaters qualify for an energy tax credit?

Yes, most of our tankless products are eligible for a $300 Federal Energy Tax Credit. There are also local rebates available for the purchase of Rinnai tankless water heaters in Austin, TX. Click here for local rebate information.

9. How much do Rinnai tankless heaters cost?

In general modern tankless units cost 2 to 2-1/2 times as much as conventional tank type water heaters. However, the energy saved typically results in paybacks of a few years or less for a family of four.

10. Why are tankless units so expensive?

Tankless units cost more than tanks, but are a better value. They save money every day, provide a high level of performance and safety, and last twice as long as a normal tank type heater. They save floor space and have a unique flexibility to be placed in locations closer to points of use to further cut energy cost and reduce water consumption. They are one of the best investments you will ever make.

11. What size Rinnai tankless unit do I need?

Click here to use our system calculator. Enter your zip code and the characteristics of your application and it will help you decide what model is best for you.

12. Rinnai makes exterior units. Do they freeze in the winter in Austin, TX?

Rinnai makes both interior units (which are sealed combustion and vented outdoors) and exterior units. All Rinnai units are designed to operate properly to outdoor temperatures of minus 30° F. Exterior units will not freeze even well below zero as long as they have electrical power and gas. However, the water connections to an exterior unit must be properly protected from cold conditions by the installer to prevent these water lines from freezing.

13. What happens if it's very cold out and I lose power?

Rinnai recommends that all exterior units used in cold climates be installed with a cold weather kit that allows water to drain out of the Rinnai automatically during a power interruption.

14. How much power does a Rinnai tankless unit use?

This varies based on the size, but this is typically less that 100 watts per hour during operation, and adds up to only a few dollars of electrical energy per year. The Rinnai operates on normal household 120 volt AC current.

15. Does a Rinnai tankless Heater have a standing pilot light?

No. It has direct spark electronic ignition.

16. How is the Rinnai interior unit vented?

Rinnai interior units are all sealed combustion and utilize a power draft system. Rinnai's exclusive pipe within a pipe concentric vent draws combustion air in from outdoors and expels flue gas back out through a single wall or roof penetration. This is the only cool to the touch tankless water heating vent system available.

17. Why do I need exterior combustion air?

Many of our competitors offer units that utilize combustion air from inside your home. While this might sound like a good idea, we have found that it is not. Tankless water heaters have a large gas capacity and can need a lot of combustion air. Most homes do not have the free space necessary to install a tankless water heater to code with out making significant modifications to your home. For us, it just makes sense to do it right the first time and not take the risk associated with improper interior make-up air design.

Even if you do have the huge open space necessary to install a system with interior combustion air, that unit will be drawing thousands of cubic feet of conditioned air from inside your home each day, and will discharge it outdoors. To replace this, outdoor air will be drawn back into your home through infiltration and will need to be warmed or cooled by your HVAC system. To us, this is an unacceptable waste of energy.

18. What is the minimum water flow rate required to operate a Rinnai?

The Rinnai tankless water heater must be able to sense water flow in order to initiate operation. Most Rinnai models will operate with flow rates as low as 0.5 gallons per minute. This is the lowest minimum flow rate in the industry and is an important benefit.

19. What does it mean when Rinnai says that the R94LSi fires from 15,000 to 199,000 btus / hour?

Unlike old style tank water heaters which fire at only one rate, most modern tankless water heaters will use only the amount of gas necessary to heat the hot water being used at any given time. To do this they measure the incoming water temperature and the flow rate, compare that to the desired output temperature, and fire at the rate necessary to meet this need. If you change any of these variables, the tankless unit re-calculates and adjusts its firing rate accordingly. The tankless unit will therefore fire anywhere between its minimum and maximum firing rate.

Rinnai units offer the lowest minimum flow rates available. As with minimum flow rates, the lower the minimum firing rate the more flexibility you will have when you only want a small amount of hot water.

20. Why do Rinnai tankless units use touch pad controls?

They allow the homeowner to interact with the water heater. You can set your desired temperature from a minimum of 98 degrees to a maximum of 140 degrees. You can verify that the unit is operating, and our optional advanced controls can perform many additional functions.

The touch pad displays any service information or error codes. This allows you, and your professional Rinnai service person, to quickly review the unit history, determine the cause of any problems, and correct those issues accurately and quickly.

21. Do all Rinnai tankless units come with Remote Touch Pad controls?

Yes, all Rinnai models come with a touch pad control.

22. I want a control in each of my bathrooms. How many controls can go on a single Rinnai?


23. I have an existing home and control wire is difficult to run. Does Rinnai have wireless controls?

Yes, and we have advanced controls that allow you to interact with your water heater even more effectively.

24. Does a Rinnai tankless unit require extra parts to be installed at higher elevations?

No, Rinnai units can be installed at altitudes as high as 10,500 feet with out any extra kits or parts.

Our R53 and R42 models have some limitations at altitude, so check with your Rinnai installer if you are considering these smaller models at higher elevations.

25. Are Rinnai tankless units field convertible from natural to LP gas or visa versa?

If you have a unit, and it needs to be converted from natural gas to LP gas, or visa versa, call Rinnai technical support at (866) 746-6241 ((866) RINNAI1).

26. Are Rinnai tankless units mobile home approved?

No. Federal law governing manufactured housing requires that gas equipment installed in mobile homes be field convertible from LP to natural gas or visa versa, and Rinnai tankless units are not convertible.