Ruud Tankless Water Heaters

A review of Ruud tankless water heaters for indoor and outdoor use in residential and light commercial applications. Get efficient and reliable on-demand heating and continuous hot water with the condensing and eco-friendly models. Ruud tankless is designed for homes with low and high demand.

Features and benefits

Condensing technology

Six gas-powered models are coming from the Professional Ultra series that utilize tankless technology for on-demand and continuous hot water supply. The key feature is the sophisticated condensing technology that utilizes the secondary condensing heat exchanger made of stainless steel, which uses the latent heat energy found in exhaust gases. This is what boosts the efficiency to a maximum of 94% (min. is 92%), making them Energy Star compliant for significant energy savings.

The secondary heat exchanger is made of stainless steel, while the primary is constructed of copper, still resistant to high temperatures and corrosion.

Due to the acidic nature of the condensate, a built-in condensate neutralizer is used, which also helps reduce the installation cost and time.

Flexible venting

All Ruud tankless water heaters are grouped in two categories - depending on the location where they can be installed: indoor models that use the 2-pipe direct vent (DV) system for moving the exhaust gases out and directing the outdoor air in, and outdoor or ventless, that can be installed outdoor only. The direct vent setup allows either horizontal or vertical termination.

Due to the lower temperature of exhaust gases and DV setup, the indoor model utilizes the PVC vent pipes, which come with a lower cost than the vents on the non-condensing models. PVC pipes are also easier to install and maintain.

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Sufficient water flow rate

All Ruud tankless water heaters, even the smallest one, are designed for the whole-house water heating since the water flow rate is high - it is in the range from 8.4 to 9.5 GPH, which is sufficient for homes with 2-3 bathrooms.

Modulating power

All the tankless units come with a digitally controlled thermostat, and due to the modulating gas valve, the temperature of hot water is easy to control and with high accuracy, while saving energy due to the smart power adjustments - to provide the required temperature.

Models review

Here is the list of the available models:

  • Professional Ultra Series: 95 DV Indoor - RUTGH-95DVL
  • Professional Ultra Series: 95 Outdoor - RUTGH-95XLN
  • Professional Ultra Series: 90 DV Indoor - RUTGH-90DVL
  • Professional Ultra Series: 90 Outdoor - RUTGH-90XLN
  • Professional Ultra Series: 84 DV Indoor - RUTGH-84DVL
  • Professional Ultra Series: 84 Outdoor - RUTGH-84XLN


Gas input
11,000-157,000 11,000-180,000 11,000-199,900
Water flow
Energy Factor
0.92 0.93 0.94
Temp. settings
85-140 85-140 85-140
# of baths 2-3 2-3 3
Controller Yes Yes Yes

Summary of the key features

  • Energy-efficient design that results in greater energy savings.
  • Advanced electronics lead to precise and convenient temperature control and problem diagnostics which can be seen as the error codes on the digital display.
  • Capability to operate as a single unit for homes with the smaller hot water demand - up to 9.5 GPM and 3-bath homes, or for large applications (hot tubs, jetted tubs, or luxury baths, for example) when using the EZ-Link Cable. The cable connects two or more units into one system.
  • Exclusive manifold capabilities allow installing up to 20 tankless units into one system by using one modulating and one remote controller.
  • Long warranty of 12 years and over 20 years expected service.
  • Exclusive Guardian overheats film wrap that protects from overheating.
  • Convenient automatic ignition for easy lighting.
  • Hot start programming allows Ruud to work with the reduced temperature fluctuation, also known as "cold water sandwiches," providing better comfort.
  • Ultra-Low NOx gas combustion making the water heaters environment-friendly.
  • Safety: freeze protection up to -30 F.
  • Temperature adjustments up to the maximum of 185 F in commercial applications.
  • High-altitude compliance up to and above 9,000 feet.


Ruud does not offer as many tankless models as the manufacturers specialized for on-demand heaters: Rinnai, Takagi, or Noritz, while they still offer powerful models with the condensing technology that is ultra-high efficient and environmentally friendly. The warranty is also great, and the parent company, Rheem, as the recognized name in the water heating industry, ensures quality and good service.

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