Rinnai RU98EN Review

A non-condensing tankless water heater is considered more efficient compared to the conventional tank-equipped type, but a condensing model is the most efficient of all, such as the Rinnai RU98EN. It is one of the most powerful water heaters from Rinnai categorized under Ultra series, featuring 0.95 energy factor, 9.8 GPM, and an easy-to-use temperature controller.

Main Features and Benefits

1. Condensing Water Heater – As mentioned earlier, the Rinnai RU98EN is a condensing tankless water heater, which is considered the most efficient model compared to others currently available. In a combustion process, fuel is burned thus it produces hot gases. In this case, hot gases are used for heating the water. With a non-condensing model, some of the hot gases are simply pushed through the vents to the outside, therefore wasted.

Rinnai RU98EN imageA condensing tankless water heater, such as the RU98EN, transfers the exhaust gases to heat the incoming water. In other words, energy optimization is much better.

2. Two Heat Exchangers – In order to operate as a condensing water heater, the Rinnai RU98EN uses two heat exchangers; one is made of steel, while another is made of copper. The stainless heat exchanger is used for recapturing the heat produced by the combustion process. The copper-made one uses pre-heated water to deliver optimum heating process above the gas burner. Cold water is already pre-heated before it flows through the primary burner, allowing for optimum heating process. According to the manufacturer, the RU98EN reaches energy factor of 0.95 for either natural or propane gas.

3. Temperature Adjustment – The Rinnai RU98EN includes a temperature controller to allow you to adjust the temperature manually as intended. The default setting only allows the temperature to go from 98 degree F to 120 degree F, but when the included controller is installed, the maximum temperature reaches up to 140 degree F. Rinnai also provides other types of compatible controllers which can be useful for commercial application where higher temperatures are necessary. The included controller can also display diagnostic codes. Possible troubleshooting methods are listed in the instruction manual.

Customer Reviews

Based on customer reviews, the Rinnai RU98EN basically does its job very well. One of the customers claimed that this tankless water heater is able to perform a good job supplying hot water simultaneously for three bathroom faucets, two showers, and one kitchen faucet. The ultra series from Rinnai is indeed designed for medium to large homes. Another good thing is that the manufacturer offers 12-year limited warranty for heat exchanger, 5-year limited warranty for parts, and 1-year warranty labor for residential installations. The RU98EN only requires a minimum water flow of 0.4 GPM or 1.5 L/minute to start.

The only noticeable drawback is that this tankless water heater can be very difficult to install without the help from professional. It is completely different from installing a tank-equipped water heater. You need to use the correct gas pipe with the correct length, diameter, etc. Moreover, improper installation will void the great warranty offers from the manufacturer. Of course, hiring a professional will cost more money also.

Where to Buy

You can purchase the Rinnai RU98EN from various online stores, but Amazon currently makes this appliance available for only $1,368.88. This price is greatly less expensive compared to the actual list price that reached $2,410.00, meaning you can save more than a thousand dollar if you purchase it from Amazon. There are also some interesting buying options such as free shipping, super saver shipping, twelve-month financing, and more.