Noritz 9.8 GPM 180,000 BTU Residential Natural Gas Direct Vent Condensing Tankless Water Heater (.90 UEF)

The Noritz NRC98-DV-NG Residential 9.8 GPM 180,000 BTU Natural Gas Direct Vent Condensing Tankless Water Heater delivers an endless supply of hot water while improving energy efficiency with a 0.90 UEF condensing design. Unlike traditional storage tank water heaters that continuously heat and store a limited supply of water, the NRC98-DV-NG heats water only when needed, helping reduce standby energy loss while providing dependable hot water for showers, appliances, and other household fixtures.

Designed for indoor direct vent installations, the NRC98-DV-NG features a powerful 180,000 BTU heating capacity and up to 9.8 GPM hot water delivery to support a wide range of residential applications. With advanced condensing technology, flexible venting options, and a compact wall-mounted design, this Noritz tankless water heater provides reliable performance, space savings, and long-term efficiency for homeowners upgrading from traditional tank systems.

Product Features:

• 180,000 BTU Input: Provides powerful natural gas heating capacity to deliver continuous hot water for residential applications.
• Up to 9.8 GPM Flow Rate: Supplies hot water to multiple fixtures, including showers, sinks, and appliances, depending on incoming water temperature and household demand.
• 0.90 UEF Condensing Efficiency: Advanced condensing technology captures additional heat from exhaust gases to improve efficiency and help reduce energy consumption.
• Direct Vent Indoor Installation: Designed for indoor installation with dedicated intake and exhaust venting for safe and efficient operation.
• Flexible Venting Options: Compatible with approved venting configurations to provide greater installation flexibility while maintaining efficient operation.
• Compact Wall-Mounted Design: Saves valuable floor space compared to conventional tank water heaters while providing an unlimited supply of hot water.
• Freeze Protection: Built-in protection features help safeguard the unit in colder environments when installed according to manufacturer requirements.
• Durable Heat Exchanger: Designed with reliable internal components to provide consistent performance and long service life.
• Energy Star® Certified: Meets high-efficiency performance standards to help reduce energy usage while maintaining dependable hot water delivery.

What Is an Isolation Valve Kit?

An isolation valve kit is an important accessory used during tankless water heater installation. These valves connect to the hot and cold water lines and allow the water heater to be shut off, serviced, flushed, or descaled without turning off water service to the entire home.

Isolation valves are especially important for tankless water heaters because regular maintenance helps protect efficiency and extend the life of the heat exchanger. Over time, mineral buildup can collect inside the heat exchanger, especially in areas with hard water. Isolation valves make it easier for homeowners or service professionals to flush the system and maintain proper performance.

Short vs. Long Isolation Valve Kit

For this Noritz NRC98-DV-NG tankless water heater, you only need to select one isolation valve kit based on your installation application.

• IK-WV-200-5-TH-S Short Isolation Valve Kit: A shorter valve kit designed for installations where space is limited or a more compact connection is preferred.
• IK-WV-200-5-TH-L Long Isolation Valve Kit: A longer valve kit designed for installations where additional clearance or easier service access is needed.

Both valve kits include 3/4" threaded isolation valves and a lead-free male pressure relief valve. The correct choice depends on available space, piping layout, and preference.

Understanding Tankless Water Heater Sizing

Unlike traditional tank water heaters, tankless water heaters are sized by flow rate (GPM) and temperature rise, not by tank capacity. Flow rate is the amount of hot water the unit can produce each minute, while temperature rise is the difference between your desired hot water temperature and the temperature of the incoming groundwater.

When sizing a tankless water heater, always use your winter groundwater temperature, as this is when incoming water is coldest and requires the most heating. The colder the incoming water, the lower the maximum flow rate the unit can produce.

For example, if your desired water temperature is 120°F and your winter groundwater temperature is 55°F, the required temperature rise is:

120°F - 55°F = 65°F Temperature Rise

Use the Flow Rate Chart in the product images to determine how much hot water can be produced at your required temperature rise. This will help determine if the NRC98-DV-NG is properly sized for your home's showers, faucets, appliances, and other hot water demands.

Warranty

This product includes a manufacturer’s limited warranty, including up to 12 years on the heat exchanger, 5 years on parts, and 1 year reasonable labor coverage for qualifying residential installations. Always verify fuel type, venting configuration, electrical requirements, water quality, required accessories, and local plumbing and mechanical codes prior to installation.