Noritz 9.8 GPM 199,900 BTU Commercial Natural Gas Outdoor Tankless Water Heater (.82 UEF)

The Noritz NC199-OD-NG 9.8 GPM 199,900 BTU Commercial Natural Gas Outdoor Tankless Water Heater is engineered to deliver reliable, continuous hot water for demanding commercial applications including restaurants, offices, multi-unit buildings, salons, and other light commercial facilities. Unlike traditional storage tank water heaters that can run out of hot water during periods of high demand, the NC199-OD-NG heats water only when it is needed, providing an endless supply of hot water while reducing standby energy loss.

Designed exclusively for outdoor installation, the NC199-OD-NG eliminates the need for indoor venting while delivering up to 199,900 BTU of heating power and a maximum flow rate of 9.8 gallons per minute. Its compact wall-mounted design helps save valuable indoor space, while commercial-grade construction, advanced temperature controls, and multi-unit capability make it an excellent solution for both new construction and replacement commercial water heating applications.

Product Features:

• 199,900 BTU Maximum Input: Delivers powerful natural gas heating capacity for demanding commercial hot water applications.
• Up to 9.8 GPM Flow Rate: Provides continuous hot water for multiple fixtures simultaneously, depending on incoming water temperature and required temperature rise.
• Commercial Non-Condensing Design: Designed for reliable commercial performance with a Uniform Energy Factor (UEF) of 0.82.
• Outdoor Installation: Factory-built for outdoor installation, eliminating the need for indoor vent piping while helping simplify installation.
• Commercial-Grade Copper Heat Exchanger: Built with heavy-duty commercial-grade copper tubing designed to withstand demanding commercial operating conditions.
• Multi-System Capability: Multiple compatible Noritz NC Series units can be connected together using optional Quick Connect or System Controller accessories for larger commercial hot water demands.
• Wide Temperature Adjustment: Adjustable outlet temperature settings from 100°F up to 185°F help support a variety of commercial applications where higher water temperatures may be required.
• Fully Modulating Burner: Automatically adjusts burner output between approximately 16,000 and 199,900 BTU to help improve efficiency and maintain consistent water temperatures.
• Direct Electronic Ignition: Eliminates the need for a standing pilot light, helping improve efficiency and reliability.
• Built-In Safety Features: Includes freeze protection, flame monitoring, overheat prevention, lightning protection, and advanced self-diagnostic capabilities for dependable operation.

What Is an Isolation Valve Kit?

An isolation valve kit is a recommended accessory for tankless water heater installations. These valves connect to the hot and cold water lines and allow the water heater to be isolated for routine maintenance, flushing, descaling, or servicing without shutting off water to the entire building.

Commercial tankless water heaters should be flushed periodically to remove mineral scale that can accumulate inside the heat exchanger, particularly in hard water areas. Installing isolation valves makes this maintenance much faster and easier while helping preserve efficiency and extend the life of the water heater.

Short vs. Long Isolation Valve Kit

For the Noritz NC199-OD-NG, only one isolation valve kit is required based on the available installation space.

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

Both kits include durable 3/4" threaded isolation valves along with a lead-free pressure relief valve. The appropriate kit depends on the installation layout and available working space.

Understanding Tankless Water Heater Sizing

Tankless water heaters are selected based on flow rate (GPM) and temperature rise rather than storage capacity. The amount of hot water a tankless unit can produce depends on how much the incoming water must be heated.

Always size a tankless water heater using your area's winter incoming groundwater temperature, since colder 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, your required temperature rise is:

120°F − 50°F = 70°F Temperature Rise

Use the manufacturer's flow rate chart shown in the product images or specification sheet to determine the expected hot water output at your required temperature rise. This ensures the water heater is properly sized for your building's simultaneous hot water demand.

Warranty

The Noritz NC199-OD-NG includes a commercial limited warranty with a 5-year heat exchanger warranty, 5-year parts warranty, and 1-year labor warranty for qualifying commercial installations. Always verify fuel type, installation location, gas supply, water quality, local plumbing and mechanical codes, and all required accessories prior to installation.