Rinnai Tankless Water Heaters Are Some of the Best in the Industry

Since its inception in September 1920, Rinnai has been striving for improving people’s lives. Their journey started in Japan with the selling of cooking oil stoves. The early 1930s were the years of expansion; the company entered into the gas appliance business including ranges and space heaters. Ever since 1964, Rinnai has been growing at a rapid pace in the field of water heating. 

Today, with offices in several countries, Rinnai is one of the most esteemed manufacturers of tankless water heaters and is using this technology to provide people with continuous warm water, adding convenience in their lives. A Rinnai water heater is reliable; you get an unlimited supply of hot water and the company offers great warranties on these products. These heaters have a top-notch efficiency rating, saving you gas bills in the long run. 

Rinnai has classified their water heaters based on the efficiency levels and a few other features. This makes it easier for you to choose from their model line depending on your needs and budget. 

Efficiency Options in Rinnai Tankless Water Heaters

Commonalities in all types

Their tankless water heaters are all offering an efficiency range of 0.79 – 0.95, which is exceptional. They can handle 3 to 4 fixtures and are Wi-Fi capable too, so you can control them remotely. The fuel used by the heaters is either natural gas or propane. 

High-Efficiency Series

This is ideal for small households, has an efficiency range of 0.79 – 0.82, and consists of only the V series line. You can attach four fixtures with it. 

High-Efficiency Plus Series

With recirculation support, these heaters offer RL and RLX lines, support up to four fixtures, and offer 0.80 – 0.81 UEF. 

Super-High Efficiency Series

This one has UEF of 0.90, supports up to three fixtures, and has two lines, it’s Energy Star compliant RUCS and RUS line. 

Super-High Efficiency Plus Series

With 0.92 – 0.95 UEF of the Energy Star compliant RUR line, 0.91-0.93 UEF of RU line, and 0.92 UEF of RUC line, this one goes at the top of the ladder of Rinnai’s efficient tankless water heaters. 

The Rinnai RL75eP tankless water heater is pretty convenient to install; you won’t have to ask a technician either. Just use the installation guide and maybe a little online help and you will be fine. 

It has an impressively low price point too; we understand these heaters are pricey as they use sophisticated technology to keep the water always warm, but this one provides exactly that without breaking the bank. 

However, it’s still an investment and in the long run, it will prove to be a money-saver. And, in the short term, you will see it as a life-changer for your family. 

You can flush or descale the interior of this Rinnai propane tankless water heater by using the provided isolation valves. The kit also comes with a pressure relief valve, making it safe and longlasting. 

Another impressive thing is its silent working; you won’t hear a disturbing sound emanating from the device. And it runs multiple showers at a time. The flow rate is 7.5 GPM, which is more than enough for multiple applications at a time, so you don’t have to worry about that either. 

The thing which impressed us the most is the flexibility in controlling the water temperature; you just have to dial in the number. This allows you to customize the water temperature according to your needs and applications. 

This Rinnai propane tankless water heater is from the Rinnai’s HE+ series and offers the UEF in the range of 0.81 – 0.82, cutting down your electricity bills and minimizing exhaust gas emissions. This Rinnai tankless water heater won’t take much space; install it wherever you want and you can get the unlimited hot water anytime.

This model also comes in a natural gas version, along with a larger 9.4-GPM version for both natural gas and propane editions. Whatever your family’s needs are, this Rinnai is an option worth considering. 




The V series Rinnai tankless water heater offers you great control over your water’s temperature, which is pretty straightforward to set too. You just have to select the temperature you want and then turn it on. 

It’s an outdoor tankless heater, so you won’t have to put up with venting or containment either. Plus, it’s pretty small for a powerful hot-water provider. You can install it in a tight spot and save space for other stuff. 

It runs on propane; if you use a 10-gallon propane tank, you won’t have to even think about refilling it for a long time. The propane gas is highly efficient, minimizing the environmental footprint and making the machine more efficient as well. 

It’s a little heavy to lift though. And the price point is a little on the higher side. However, once you install the device, it’s totally worth it. 

You get an unlimited supply of hot water. Water present in the tanktop water heater can corrode the surface of the tank. This one doesn’t have a tank, so it won’t need much maintenance as well, making it longer lasting than the traditional water heaters. 

Two people in different bathrooms can conveniently take a hot-water shower at the same time with the 6.5 GPM water flow rate of this V series tankless water heater. 

With the energy factor of 0.82, you will get the return on investment in no time; it uses most of the gas to heat the water and wastes less energy than storage tank water heaters. 




Want an unusually quiet Rinnai tankless heater? This one will not disappoint you. It’s impressive how the heater works so silently and provides hot water at the push of a button. 

It’s important that you install an isolation valve kit so that you can flush it out after a year or two. There is a window that will let you observe the flame; it’s a good idea to check it and make sure it’s a solid blue flame every once in a while. 

The Rinnai tankless water heaters are reliable and outlast many of their competitors. You will get your return on investment over time with this Rinnai water heater, but it’s the convenience that outweighs the ROI; going tankless with this water heater can add significant value to your quality of life and carbon footprint. 

If you are a 3-4 person household, this Rinnai model will suit you well. It’s better to install the device closer to the water sources as the hot water could take time to reach the outlet. 

It’s easy to install; just follow the guide and make sure you don’t forget about flushing it after a year. It may save on your electricity and gas bills, and won’t contaminate the air much, making you a good environmentalist. 

If you have hard water in your water supply, don’t ignore regular maintenance, and by regular we mean once every year. Otherwise, it could hinder its effectiveness. Install the isolation valves and just follow the instructions; flushing the Rinnai tankless water heater is pretty straightforward. 

With a 6.5 GPM flow rate, this Rinnai propane tankless water heater will be ideal for a small household. This one is for indoor installation only, so you need to get it good ventilation so that you don’t encounter any errors down the road. 

You can even put it into vacation mode remotely with the control-R 2.0 app. The energy factor is 0.82, so it will probably bring down the utility bill as well. 




This RU series Rinnai water heater will have your hot water delivered to your shower within seconds. It won’t take longer than a minute if your shower is located even 2 floors above, ensuring less water loss. Plus, Rinnai’s Circ-Logic technology allows you to set patterns of recirculation according to your needs.  

And it’s safe to say that you can run 3 showers at a time with this one. Its flow rate is a whopping 11-GPM, so you may get to run more than that, making it perfect for medium-sized households.  

If you get distracted by unwanted noises easily, there is good news this Rinnai model won’t bother you as it’s relatively quiet and does the job without much sound. 

The equipment comes with everything required for an effective installation; you just have to follow the guide to install it. It’s pretty easy to install if you are good at DIY projects. If you don’t feel confident, it’s advisable to call the appropriate guy for installation. 

One thing to consider is that it consumes higher quantities of gas, so if your gas line can’t take 199k BTUs, you may have to change it.  

The impressive thing about the Rinnai RU series is that you won’t have to worry about running out of water anytime, which gives you peace of mind. 

With indoor installation, the device won’t get affected by any harsh weather conditions, making it less prone to rust and corrosion over time. 




The Rinnai tankless water heaters come with a comprehensive installation guide; it breaks down the steps involved, making the installation convenient. This one is also pretty straightforward to install; just make sure you follow the guidelines and be confident in doing so. After all, it’s a longterm investment; you want to do it right. 

The unit is highly energy-efficient and will return your investment in a couple of years. It won’t waste much gas, saving more for water heating. 

It’s an unlimited supply of water, a big convenience if you love to take hot-water showers frequently. Plus, multiple showers and faucets can be used simultaneously with this Rinnai water heater

The water may come a few seconds late, but you can configure a recirculation pump with the device to get instant hot water if you think the convenience is worth extra energy bill. 

Hard water in your supply line can ruin the interiors of this device; make sure it’s not hard water. If it is, you will have to descale/flush the system at least twice a year; if you don’t do it, it may render the unit useless in about 3 years.

A water softener is a great solution for hard water problems. You won’t be needing much maintenance with the softener installed, which can really give you peace of mind. 

With up to 0.96 energy factor, this Rinnai water heater minimizes the energy loss, using most of the energy for heating, and in turn, bringing down your utility cost. 

Plus, the compact design allows you to install it indoors with minimum space. And you have a PVC venting choice, bringing down your installation costs.




The Rinnai CU199in tankless heater offers you a very high GPM of 11. So, if you have a large household, or just want multiple showers at a time, this one will be a good option for you. You can use more than 4 showers at a time with the 11-GPM flow rate of this tankless heater. 

The design of the device is compact; giving you more flexibility to install it. This is an indoor unit designed for commercial needs and it can be easily wall mounted as well, saving your floor space. 

Its efficiency is a whopping 0.97; with this, virtually no energy is lost and you get to pay fewer bills in the long run. The exhaust gases are minimum, so it’s good for the atmosphere too. All in all, it’s a great upfront investment of which you can reap the benefits downstream. It’s an Energy Star qualified product, after all. 

Plus, it’s recirculation capable. With this technology, the initial cold water after opening a tap is heated as well, saving a lot of water down the road. The device is Wi-Fi capable, letting you control it remotely. 

In addition, you get a 96 months heat-exchanger warranty, which can add to the peace of mind while buying the product.

You can install this tankless water heater indoors. This way, the device remains safe from the outside environment and any unwanted weather events. In summary, if you want a commercial tankless water heater that has a very high flow rate and great efficiency, this would be a good option. 





How to Reset Rinnai Tankless Water Heater?

To reset the system, turn all hot water taps off, press on and off a couple of times, and turn on the hot water again to check. Try this for a couple of times to reset the unit.

How to Flush a Rinnai Tankless Water Heater?

Rinnai tankless water heater maintenance is necessary for ensuring safe and longterm usability. First, turn off the electric and gas connections to the unit. Close the valves bringing water inside and taking it outside the system. If you don’t have flush valves, install them first. 

You would need a pump which can pump the cleaning agent into the unit. Connect a hose to the cold water outlet and put the other end of it into the tub. Attach the other hose to the pump and the hot water inlet. Pour a vinegar-water solution into the tub. 

The pump will push the solution in through the hot water valve, letting it exit from the other side (cold water flush valve). Let it run for an hour or so and your tankless water heater will get flushed. 

How to Adjust the Temperature on Rinnai Tankless Water Heater?

The method is fairly straightforward and applies to all models of Rinnai that are offering a temperature controller. After turning the device on, press the upward or downward arrow to adjust the temperature of the water you want. 

How to Clean a Rinnai Tankless Water Heater?

For cleaning the unit, use a pump and a vinegar solution to flush out the impurities using the isolation valves (flush valves). You can use the method discussed above for flushing the unit. 

What Size Rinnai Direct Vent Heater do I Need?

It depends on your requirement. For a small to medium family, a tankless water heater with a flow rate of around 6-GPM would suffice. They are usually of small sizes and don’t take up much space. 

Rinnai Tankless Water Heater Manual

All Rinnai tankless water heaters come with a comprehensive and easy-to-understand installation manual. It is your guide every step of the way. You can also contact the technical support team if you encounter any problem along the way. 

Rinnai Tankless Water Heater Warranty

The warranty on the Rinnai water heaters’ heat exchanger is 12 years for the residential applications and 5 years for commercial ones. 

Rinnai Tankless Water Heater Beeping

If your Rinnai water heater starts beeping, it may be due to a leakage of water in the line. A sign of such an event would be a wet floor near the unit. Plus, the beeping may also occur due to a gas leak.