Review: Rinnai RL75iN Natural Gas Tankless Water Heater

Water Heater Review

If you’re looking to upgrade your hot water heater to something a little more efficient you need to consider a tankless model such as the Rinnai RL75In Natural Gas Water Heater. Tankless water heaters are designed to provide continuous hot water without using nearly as much energy as a traditional water heater. This Rinnai model is one of the top choices for going tankless in 2014.


The Rinnai RL75In is a modern water heater if there ever was one and this tankless model comes with all the awesome features to prove it.

  • Comes with a digital controller and Error Code Indicator
  • Residential temperature setting options: 98°F – 140°F
  • Commercial temperature setting options: 98°F – 160°F (commercial controller purchased separately)
  • Energy Star Certified
  • Twelve-year warranty on heat exchanger
  • Five-year warranty on parts
  • 10,300 – 180,000 BTU

Ideal for two or three bedroom homes, you can mount the Rinnai RL75iN in almost any room and vent directly to the outside with a single roof or wall penetration.


compact design of this tankless hot water heater makes for easy installation in most any room in your house. You won’t have to worry about this water heater being an eyesore or taking up too much unwanted space. It’s capable of putting out anywhere from 10,000 to 180,000 BTU’s and delivers 7.5 gallons of hot water per minute.

The digital controller that comes with the water heater is simple and easy to use so you won’t encounter any problems adjusting the heat of your water. The best part of the controller is that it features an error code indicator which provides you with a specific code for troubleshooting a problem if something ever goes wrong.

This is an incredibly energy efficient tankless hot water. It requires minimal maintenance – flushing the unit every one or two years to dissolve calcium deposits in the heat exchanger – and cleaning. That’s a pro in most everybody’s book.


There aren’t many cons to list about the Rinnai RL75iN but there are a few nonetheless. This hot water heater will make endless hot water – but it can only do so much at a time. It’s only capable of running two or three fixtures at once so it’s not recommended that you try and do a load of laundry, run the dishwasher, and have someone in the shower all at once.

The only other issue with this tankless hot water heater is finding service for the unit if you have a problem (which thankfully, doesn’t happen often). Rinnai has an online dealer locator but if you haven’t bought your unit from that specific dealer, it’s kind of like bringing your own meal to a restaurant. Brace yourself to pay the service man if you ever have any problems.


Yes. Overall, the Rinnai RL75iN Natural Gas Tankless Hot Water Heater is one of the best available on the market in its class. It’s efficient, it’s easy to maintain, and it’s reliable as long as you’ve had it installed to perform a job within reason.

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