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    Rinnai RL 75in Tankless Water Heater Review

    Review of Rinnai RL 75in

    The Rinnai RL 75in tankless water heater is an indoor, non-condensing, energy-efficient unit built by a leading manufacturer in the industry. If you're looking for a powerful gas tankless that's capable of providing a nearly endless supply of hot water, you'll want to read this review.

    We'll take a detailed look at the Rinnai RL 75in and cover pro's and con's and other features the unit delivers. Buyng a tankless water heater is an investment, and we'll help you decide of if the RL 75in is the right model for you.

    Why The Rinnai RL 75in?

    A tankless water heater operates differently than their tank-style cousin. Cold water passes thru the tankless while its monitored by internal sensors which ensures that the water delivered at the faucet is hot.

    If you've started shopping, you're probably aware that there's a wide variety of options when it comes to tankless water heaters. So why the Rinnai RL 75in?

    Well, to begin with, the RL 75in is ideal for two or three-bedroom homes. When the ground water temperature is 57-degrees Farenheit this unit can service up to 3 fixtures at a flow rate of 4.7 gallons of hot water per minute. And in warmer climates, the RL 75in can deliver a maximum of 7.5 gallons per minute!

    It's also compact and can be mounted in nearly any room within your home provided it's vented to the outside. The unit's vent is located on the top, but you'll have the option of running the venting through either the roof or a wall, which gives you plenty of installation options.

    The Rinnai RL 75in tankless water heater runs exceptionally quiet, especially considering it's high performance. Let's take a look at some of the unit's stats:

    • Dimensions: 14 x 9.3 x 23 inches
    • Weight: 45 pounds
    • Energy Factor of 0.82 (Uniform Energy Factor of 0./81)
    • 10,300 BTU/h 3.0 kWh Minimum (180,000 BUT/h Maximum) 
    • Residential Temperature Settings: 98-140 degrees F
    • Water Consumption: 7.5 Gallons
    • Direct electronic ignition
    • Manufacturer Warranty: 12-year warranty of the heat exchanger, 5-years on parts, and 1-year labor for residential installations.
    • Commercial settings: By adding a commercial controller the upper range of temperatures can increase to 160 degrees F.


    BTU (British Thermal Unit) is the amount of heat required to raise the temperature of one pound of water by one degree.

    GPM (Gallons per Minute) measures how much water can be delivered consistently.

    Rinnai RL Series HE+ Tankless Hot Water Heater: Indoor Installation

    Pro's and Con's

    The Rinnai RL 75in is an on-demand water heater, but not an "instant on" heater. That means it will still take time for the water to heat up and run through the pipes. Once it's running, however, you should have an endless stream of hot water.

    If you're looking for "instant" hot water, you may want to consider adding a point-of-use water heater to provide hot water until your main system can take over. They are excellent for remote bathrooms and other areas where you need hot water fast. A circultaion pump is another option, as they will keep the hot water moving in the pipes.

    A very low water flow is needed to activate the RL 75in. Activation occurs with water flows as low as 0.26 GPM, making this tankless water heater great for situations where low flow is required. Such as using with low-flow fixtures or doing quick tasks like washing your hands or shaving.

    There's no pilot light on the unit. Ignition is electronic and happens automatically. That means you'll never have to find matches and get on your hands and knees to get the pilot light lit.

    If your hot water capacity increases as your family grows the RL 75in can grow right along with you. Simply use Rinnai's EZ Connect system and you can connect two identical models together. 

    When you install a tankless water heater you'll be working with electrical, gas, plumbing and venting, many areas require permits. All tankless units should be installed by a professional, and Rinnai's units are no exception. 

    Feature Overview

    When it comes to features, the Rinnai RL 75in has just about anything you could want in a tankless water heater. There's even a couple of cool tech toys to keep the techies satisfied. Afterall, who doesn't want to control their water heater with Alexa or have it send a text message when it needs maintenance?

    Temperature Control

    The Rinnai RL 75in tankless water heater has a temperature controller on the front panel with up / down arrows to make temperature adjustments easy.

    Diagnostic Capabilities

    The electronic panel is also used for diagnostics and to display error codes. The unit is wi-fi enabled so you can add Control-R and take advantage of remote monitoring and management.

    The RL 75in will literally let you know if there's a problem or if maintenance is needed. If you choose, you can even connect your unit with a Rinnai dealer who can monitor your unit remotely!

    Energy Efficiency

    With a tankless water heater, you're heating water on demand, which simply means there is less wasted energy. A tank-syle water heater holds the hot water until you need it, and keeps heating the water in the tank to keep it hot.

    Switching to a tankless will make a big impact on your utility bills. An Energy Star tank-style gas water heater typically has an EF (energy efficiency rating) between .67 and .70. The RL 75in's EF rating is .81. Which means that 81% of the energy the unit draws is used to heat water.

    Advanced Technology

    The optional 24-hour programmable digital controller will schedule around your daily usage patterns. And if your home is set up with Alexa, you can even control the unit with voice prompts!

    Optional Features

    Rinnai offers a full line of options to customize the system. You can add options such as a pipe cover, wi-fi control module, EZ connect cables, and even an external recirculation pump.

    Final Thoughts

    Buying a tankless water heater is a significant investment. With proper care, a tankless can last over 20-years, which means you'll be living with your choice for a long time. 

    That's why it's important to do your research. Take into account your hot water needs, which features are important to you, the efficiency of the unit and the reputation of the manufacturer.

    If you're looking for an indoor gas tankless water heater, the Rinnai RL 75in is worthy of being on your short list. It's a hard working unit that can deliver up to 7.5 gallons of hot water per minute.  

    While there may be more budget-friendly solutions on the market, you can fee confident that if you buy a Rinnai the investment you make today will be running strong years from now.