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

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

Designed for indoor installation, the NC199-DVC-NG utilizes a direct vent concentric system that supplies combustion air and exhaust through a single vent assembly, helping simplify installation while maintaining safe operation. Delivering up to 199,900 BTU of natural gas heating power and a maximum flow rate of 9.8 gallons per minute, this commercial-grade tankless water heater combines reliable performance, compact wall-mounted installation, and advanced temperature controls for years of dependable service.

Product Features:

• 199,900 BTU Maximum Input: Provides powerful natural gas heating capacity for demanding commercial hot water applications.
• Up to 9.8 GPM Flow Rate: Supplies continuous hot water to multiple fixtures simultaneously depending on incoming water temperature and required temperature rise.
• Commercial Non-Condensing Design: Engineered for dependable commercial operation with a Uniform Energy Factor (UEF) of 0.82.
• Direct Vent Concentric System: Uses a single concentric vent assembly for combustion air intake and exhaust, simplifying indoor installation while maintaining safe operation.
• Commercial-Grade Copper Heat Exchanger: Built with a heavy-duty copper heat exchanger designed to withstand demanding commercial operating conditions.
• Multi-System Capability: Compatible with optional Noritz Quick Connect and System Controller accessories, allowing multiple units to work together 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 requiring higher water temperatures.
• Fully Modulating Burner: Automatically adjusts firing rate between approximately 16,000 and 199,900 BTU to help maintain consistent outlet temperatures while improving energy efficiency.
• Electronic Ignition: Eliminates the need for a standing pilot light, improving efficiency and long-term 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 flushing, descaling, maintenance, or servicing without shutting off water to the rest of the building.

Commercial tankless water heaters should be flushed periodically to remove mineral buildup that can accumulate inside the heat exchanger, especially in areas with hard water. Isolation valves make routine maintenance significantly easier while helping preserve efficiency and extend the life of the unit.

Short vs. Long Isolation Valve Kit

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

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

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

Understanding Tankless Water Heater Sizing

Tankless water heaters are sized using flow rate (GPM) and temperature rise rather than storage capacity. The amount of hot water the unit can produce depends on how much the incoming water must be heated before it reaches your desired outlet temperature.

Always size a 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 the incoming groundwater temperature is 50°F, the required temperature rise is:

120°F − 50°F = 70°F Temperature Rise

Use the manufacturer's flow rate chart included with the product literature to determine the expected hot water output at your required temperature rise. This helps ensure the water heater is properly sized for your building's simultaneous hot water demand.

Warranty

This product includes Noritz's commercial limited warranty featuring a 5-year heat exchanger warranty, 5-year parts warranty, and 1-year labor warranty for qualifying commercial installations. Always verify natural gas supply, approved direct vent concentric venting requirements, electrical requirements, water quality, local plumbing and mechanical codes, and all required accessories prior to installation.