Rinnai RV53 Tankless Water Heaters Review and Buying Tips

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Rinnai RV53 tankless water heaters are the smallest units from all Rinnai appliances. These economy models also called "value models", are recommended for residential water heating in non-freezing climate regions mainly, and in smaller homes with up to 2 bathrooms.

When compare to other tankless models from Rinnai, RV53 series come with the 10-year warranty on heat exchangers, while other series have 2 years longer warranty.


Rinnai RV53 overview


There are two models from RV53 series available: Rinnai RV53i for indoor use and model RV53e designed for the outside installation. These models are small and compact units that are easy to install on the wall and thanks to simple commands, use.


They are designed with the maximum water flow of 5.3 gallons per minute that can supply one to two applications at the same time. If more hot water is needed you can use EZConnect cable to connect two indoor models to work as one.


rinnai rv53iAn indoor unit RV53i is direct vent water heater with a sealed combustion that uses a vent system to bring the outside air in for gas combustion and forcing the exhaust gases out, making it safe to use inside the home (bathrooms and kitchen).

While an indoor model uses the venting system with the horizontal or vertical termination, the outside model doesn't require any venting since it is already mounted outside. It can use the recessed box for better look and protection.

Rinnai models RV53 are built with the tankless technology which allows them to provide hot water on demand, continuously, and as long as you needed it.


rinnai rv53eThey are designed to work with the maximum 120,000 BTU, for Rinnai RV53e and 150,000 BTU for RV53i model, while the minimum power they can get is approximately 19,000 for the outdoor and 15,000 BTU for an indoor model.

This is possible as the units are equipped with the modulating gas burner, which adjusts the power based on the set temperature and water flow.
Modulating burner allows these Rinnai units consistent temperature with less hot water temperature fluctuation and more energy savings.

Remote controller

For the more accurate control of the outgoing hot water temperature, it is recommended to get the MC-91 controller. The temperature controller can set the temperature of the outgoing hot water and show the error codes for diagnosing the problem and easy troubleshooting.

If the water heater does not use the temperature controller, then the temperature can be adjusted by putting the switch in the correct position.


Rinnai water heater is constantly checking its water heating operation. If there is a problem with the heater, the error code such as 0.2, 0.3, 11 or any other, will display on the remote control if it is installed. If it is not installed then the error code will flash on the control panel.

Even with smaller capacity and power, water heaters RV53i and RV53e are still high efficient units and Energy Star compliant.

Safety elements

  • Flame rod - the water heater will automatically shut down if the burner flame goes out

  • Combustion fan rpm check

  • Over current protection - if the fuse blows all the lamps will be OFF

  • Thermal fuse will break if the overheat feature does not prevent the temperature from rising, and will shut off the unit

  • Automatic frost protection

  • Remaining flame - OHS


  • Energy factor is 0.82 for both indoor and outdoor unit

  • 10-year limited warranty on the heat exchanger and 5 years on other parts

  • Temperature setting is from 98-140 F. The units are factory set on 120 F.

  • Meet California and Texas NOx emission requirements

  • Direct electronic ignition

  • Gas and water fitting size is 3/4"

  • Water pressure range is from 20-150 PSI

  • Certified for mobile and manufactured home installations

  • Compatible with Rinnai controllers

  • Hot water capacity is from 0.6 to 5.3 GPM

  • Approximately weight: 34 for the RV53e and 51 pounds for RV53i

Rinnai RV53 is the great solution for those who need a reliable tankless water heater that supplies hot water with the consistent temperature, on demand, and for up to two applications. An Energy Star compliance ensures that these water heaters save on energy and provide efficient water heating.

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Pictures - courtesy of Rinnai WH company

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