Rinnai RL75iN Review


Rinnai is a well-known and reliable brand that always manages to introduce top quality, efficient and innovative tankless water heaters. RL75iN is not different. Rinnai RL75iN is a powerhouse of amazing features and far superior to other models in technology domain. This heater runs on Natural gas and has a contemporary and sleek outlook that easily can be fitted to any nook and corner of your house. Unlike traditional tanked models, this heater doesn’t need electricity supply or a blizzard of pipes and tubes for operating and producing hot water. The minimum gas rate that it utilizes is 10,300BTU and maximum rate is 180,000BTU. It is an eco-friendly product that already meets the NOx emission standards of Texas and California. RL75iN energy factor is 0.82, which means it is around 82% energy efficient. This heater comes with a digital remote control that is equipped with Error Code Indicator. This indicator notifies the user about any probable issues that need immediate attention and fixing.

The Pros & Cons of the Rinnai RL75iN Natural Gas Heater


  • Since it is gas powered you can easily save a lot of money on your utility bills
  • This model doesn’t have a water tank and the water is heated only when you demand it which makes it a feasible option if you want to save energy resources
  • Its noiselessness is an important advantage because even if you have installed it in your bedroom the heater run literally noiselessly
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    The fact that this heater produced 7.5Gallons hot water per min is highly impressive
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    Installation is fairly simple and easy which becomes even more simplistic with the very useful and helpful DIY setup guide. The guide provide detailed information about the components and tools required and relays the complete installation process in a step-by-step style


  • The unit uses less natural gas in comparison to tanked heaters but one key drawbacks is that it more natural gas than some other more efficient models
  • Just like other models of tankless water heaters, this unit also cannot supply hot water instantly and continuously and the probability of cold sandwich effect cannot be overlooked

Installation and Specifications

You can easily install it yourself using a DIY approach since the package comes with an elaborative and easy to comprehend user manual. However, we would recommend that you get professional help especially if you don’t have any prior experience with natural gas heaters. You need to use only the listed and tested exhaust/combustion air vent and not any other one. The unit utilizes outdoor air for combustion, which makes it very safe to be used for residential purposes. RL75iN has direct vent sealed combustion that lets the unit to be easily installed in bedrooms, kitchens and bathrooms where conventional B-Vent water heaters cannot be fitted. However, the heater offers limited capacity as far as termination of vent is concerned and you must check installation manual to ensure the required limit.


Assembled Depth9.3"
Assembled Height23"
Assembled Width14 "
Product Depth9.3"
Product Height23"
Product Width14"
Vent diameter0"
Water Connection Size3/4"
Finish FamilyGray
Flow Rate @ 35 F Rise (gallons/min)7.5 gal (US)/min
Flow Rate @ 45 F Rise (gallons/min)7.5 gal
Fuel TypeGas
Gas Connection Size3/4"
Gas Product TypePoint of Use
Gas TypeNatural Gas/Propane Gas
Maximum Temperature (F)140
Minimum Activation Rate (gpm)0.4
Minimum Temperature (F)98
Product Weight (lb.)45.6 lb
Residential/Commercial/industrial UseResidential or commercial
Total BTU180000.000
Water Connection LocationBottom
Water Heater FeaturesWall Mountable
Vent TypeSingle Wall

Common Problems

Since it is highly efficient and utilizes more gas for heating water therefore, when the unit is operating the other natural gas outlets at home tend to work less efficiently because of the huge burden RL75iN imposes on gas supply. Another problem is that when you purchase this heater online, the warranty terms get affected and it becomes impossible to receive any kind of compensation or repairs from the manufacturer if you have purchased it online. However, considering the low gas consumption and smart technology that this model offers, it is a great deal for fulfilling hot water demand of a medium sized family.


Overall, the Rinnai RL57iN is a great way to get a constant water supply whilst saving on gas expenses, though this is a benefit of the tankless water heater system rather than this particular product. Problems with the warranty and other problems endemic to this technology make the Rinnai RL57iN less appealing than it should be.

You can buy the Rinnai RL75iN on Amazon.

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