Noritz 5.0 GPM 120,000 BTU Residential Propane Outdoor Tankless Water Heater (.82 UEF)

The Noritz NR501-OD-LP 5.0 GPM 120,000 BTU Residential Propane Outdoor Tankless Water Heater provides dependable, on-demand hot water in a compact, energy-efficient design that's ideal for apartments, condominiums, townhomes, and smaller single-family homes. Unlike conventional storage tank water heaters that continuously heat and store water, the NR501-OD-LP heats water only when a hot water fixture is opened, helping reduce standby energy loss while providing a continuous supply of hot water.

Designed exclusively for outdoor installation, the NR501-OD-LP requires no venting, helping simplify installation while saving valuable indoor space. With up to 120,000 BTU of propane heating capacity and a maximum flow rate of 5.0 gallons per minute, this compact wall-mounted tankless water heater delivers reliable performance for homes with one to two bathrooms. Its durable copper heat exchanger, fully modulating burner, built-in freeze protection, and user-friendly controls provide years of dependable residential hot water performance.

Product Features:

• 120,000 BTU Maximum Input: Provides reliable propane heating capacity for everyday residential hot water needs.
• Up to 5.0 GPM Flow Rate: Delivers continuous hot water for showers, faucets, dishwashers, and washing machines depending on incoming water temperature and simultaneous household demand.
• Outdoor Installation: Factory-built for outdoor installation, eliminating the need for additional vent piping while simplifying installation.
• Non-Condensing Design: Delivers dependable performance with a Uniform Energy Factor (UEF) of 0.82 while heating water only when needed.
• Commercial-Grade Copper Heat Exchanger: Durable copper heat exchanger is designed for long-lasting residential reliability.
• Compact Wall-Mounted Design: Small footprint helps free up valuable indoor living space while providing convenient outdoor installation.
• Adjustable Temperature Settings: Includes standard temperature settings of 120°F (factory default), 130°F, 135°F, and 140°F for residential comfort.
• Fully Modulating Burner: Automatically adjusts between approximately 15,000 and 120,000 BTU to maintain consistent outlet water temperature while improving fuel efficiency.
• Freeze Protection: Built-in freeze protection helps safeguard the unit during cold weather when installed according to manufacturer guidelines.
• Advanced Safety Features: Includes flame sensor, overheat prevention device, fan rotation detector, lightning protection, temperature lockout, high elevation adjustment, and a built-in diagnostic display.

What Is an Isolation Valve Kit?

An isolation valve kit is a recommended accessory for every tankless water heater installation. Isolation valves connect to the hot and cold water lines, allowing the water heater to be isolated for maintenance, flushing, descaling, or servicing without shutting off water to the entire home.

Regular flushing helps remove mineral deposits that naturally accumulate inside the heat exchanger, especially in areas with hard water. Installing isolation valves simplifies routine maintenance while helping preserve efficiency and extend the service life of the water heater.

Short vs. Long Isolation Valve Kit

For the Noritz NR501-OD-LP, only one isolation valve kit is required based on your installation layout.

• IK-WV-200-5-TH-S Short Isolation Valve Kit: Recommended for installations with limited space where a compact valve assembly is preferred.
• IK-WV-200-5-TH-L Long Isolation Valve Kit: Ideal when additional clearance is available for easier future servicing and maintenance.

Both kits include durable 3/4-inch threaded hot and cold isolation valves together with a lead-free pressure relief valve.

Understanding Tankless Water Heater Sizing

Tankless water heaters are sized using flow rate (GPM) and temperature rise rather than tank capacity. Flow rate represents the amount of hot water the unit can produce each minute, while temperature rise is the difference between the incoming groundwater temperature and the desired outlet temperature.

Always size your tankless water heater using your area's winter groundwater temperature, since colder incoming water requires more heating capacity and reduces the maximum available flow rate.

For example, if your desired hot water temperature is 120°F and your incoming groundwater temperature is 50°F, the required temperature rise is:

120°F − 50°F = 70°F Temperature Rise

Use the Noritz flow rate chart included with the product literature to determine the expected hot water output at your required temperature rise and ensure the unit is properly sized for your home's simultaneous hot water demand.

Warranty

The NR501-OD-LP includes Noritz's residential limited warranty featuring a 12-year heat exchanger warranty for standard residential applications, a 5-year parts warranty, and a 1-year reasonable labor warranty. When used with a recirculation system, the heat exchanger warranty is reduced to 3 years. Always verify propane fuel supply, installation location, water quality, local plumbing and mechanical codes, electrical requirements, and all required accessories before installation.