7.5 GPM 160,000 BTU Exterior Natural Gas Tankless Water Heater

The RUS75EN is Rinnai's exterior, natural-gas tankless water heater, built in stainless steel for outdoor mounting on homes that want on-demand hot water without a storage tank. Location is listed as indoor or outdoor, with a maximum input of 160,000 BTU.

Rinnai lists a maximum flow value of 7.5 on the spec sheet; delivered flow varies with incoming groundwater temperature, so a qualified installer can confirm expected output for your site. The unit is Energy Star qualified, with an energy factor of 0.93 and a Uniform Energy Factor of 0.89, and runs on 120-volt power. The cabinet measures 27 inches high, 18.5 inches wide, and 10.5 inches deep, and weighs 57.3 pounds.

Installation is wall-mounted and requires professional service; the unit is direct vented, rated to a maximum working pressure of 150 PSI between 98°F and 120°F, and Title 24 listed for California. Rinnai's Control-R Wi-Fi module and mobile app are no longer compatible with this RUS-series heater. A qualified installer should confirm clearances, gas-line sizing, and local code before installation.

This listing is for the water heater itself. Gas piping, electrical connections, mounting hardware, and venting materials are not included unless stated.

Rinnai's limited warranty covers the heat exchanger for 10 years, parts for 5 years, and labor for 1 year.

Delivery and returns: this water heater ships free by ground delivery and arrives within the window shown above. If it is not the right fit, return it free within 30 days in its original packaging.

• Installation and Clearances

  This exterior, wall-mounted unit requires professional installation. Confirm the mounting surface, outdoor exposure, service access, and local code clearances before work begins. The page does not give a numerical clearance schedule, so have a qualified installer determine the required spacing for the site.

• Direct Venting

  Direct venting is required for this gas appliance. Confirm the approved vent system, adaptor requirements, route, termination, and clearances in the current installation documentation. A qualified installer should size and install the venting and verify the finished installation before operation.

• Natural Gas Supply

  This listing is the Natural Gas configuration with 160,000 BTU maximum input. Before ordering, have a qualified installer verify gas-line sizing, supply pressure, connection requirements, and local code. Do not substitute a propane setup for this natural-gas unit.

• Flow and Temperature Rise

  The page lists a 0.26 GPM minimum flow and a 7.5 maximum-flow value, while its performance graphic shows 3.5 to 6.9 GPM across ground-water temperatures from 35°F to 77°F. Actual flow depends on incoming water, temperature rise, and simultaneous hot-water demand.

• Controls and Recirculation

  Plan temperature controls and any recirculation equipment with the installer. The page warns that its Wi-Fi module and mobile app are not compatible with this heater family. Verify control, wiring, pump, and accessory compatibility before ordering, and do not assume an accessory is included.

• Efficiency and Power

  The page identifies this unit as Energy Star qualified and lists a 0.93 energy factor with 0.89 uniform energy factor (0.89 UEF). Its specification table lists 120 Volt power. Confirm the electrical connection, efficiency documentation, and installation requirements for the intended location with a qualified professional.

• Descaling and Maintenance

  Water quality and use can affect service needs. Follow the current service documentation for flushing, descaling, cleaning, and maintenance intervals rather than relying on a generic schedule. Have a qualified technician perform gas-appliance service when required, and keep the exterior clear for inspection.

• Warranty Terms

  The page lists a 12 Years warranty length and separately gives detailed residential coverage of 10 years on the heat exchanger, 5 years on parts, and 1 year on labor. Review the written limited warranty, registration requirements, and installation conditions before purchase.

• What Ships

  The listing identifies the tankless heater but does not provide a complete in-the-box contents list. Confirm what is included before scheduling installation. Treat venting, gas fittings, electrical materials, controls, and recirculation equipment as separate requirements unless the order explicitly says they ship with the heater.

Good to know

• 18.5″ W × 10.5″ D × 27″ H; wall mounted.
• Natural-gas configuration; verify supply sizing.
• Direct vent required; confirm clearances and termination.
• Exterior installation; confirm local code and service access.
• Professional installation is required for gas, venting, electrical, and water connections. Have a qualified installer confirm local code requirements, clearances, supply sizing, and commissioning before operation.
• Tankless water heater only. Installation materials, venting components, controls, and other items shown or required are not included unless explicitly stated.