The Noritz EZ98-DV-NG EZ Series Pro 9.8 GPM 180,000 BTU Natural Gas Tankless Water Heater delivers endless hot water while helping reduce energy costs with an ultra-high 0.98 UEF Energy StarĀ® certified condensing design. Unlike a traditional tank water heater that stores a limited supply of hot water, the EZ98 heats water only when you need it, so you can enjoy long showers, run multiple hot water fixtures, and never wait for a tank to recover.
Designed for both new installations and replacement projects, the compact EZ Series cabinet saves valuable space while simplifying installation. With powerful 180,000 BTU performance, up to 9.8 GPM of hot water delivery, and flexible indoor or outdoor installation options, the EZ98-DV-NG is an excellent replacement for many 50 to 75-gallon tank water heaters, providing reliable hot water and exceptional energy efficiency for years to come.
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 to the entire home.
Isolation valves are especially important for tankless water heaters because regular maintenance helps protect performance and efficiency. Over time, mineral buildup can collect inside the heat exchanger, especially in areas with hard water. Isolation valves make it much easier for a plumber or homeowner to flush the system and help extend the life of the unit.
For this Noritz EZ98-DV-NG tankless water heater, you only need to select one isolation valve kit based on your installation application.
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 installer preference.
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 ground water.
When sizing a tankless water heater, always use your winter ground water temperature, as this is when the 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 120Ā°F and your winter ground water temperature is 55Ā°F, the required temperature rise is:
120Ā°F - 55Ā°F = 65Ā°F Temperature Rise
Using the Flow Rate Chart in the product images to determine how much hot water can be produced at your required temperature rise. The GPM is approximately 5.3 based on the chart on the EZ98 at a 65Ā°F temperature rise, and a standard shower uses approximately 2 GPM. This means you can comfortably run 2 showers at the same time, with additional capacity for another low-flow fixture.
This product includes a manufacturer's limited warranty, including up to 25 years on the heat exchanger, 5 years on parts, and 1 year reasonable labor coverage for qualifying installations. Always verify fuel type, venting configuration, electrical requirements, water quality, required accessories, and local plumbing and mechanical codes prior to installation.
The Noritz EZ98-DV-NG is a residential condensing tankless water heater engineered to deliver reliable hot water performance for medium to large households. As part of the Noritz EZ Series Pro lineup, this natural gas model provides up to 9.8 gallons per minute with a maximum input of 180,000 BTU, supporting continuous hot water delivery for multiple simultaneous fixtures and appliances.
Built with condensing technology and advanced burner modulation, the system continuously adjusts heating performance based on demand to maintain stable outlet temperatures and efficient operation. With a Uniform Energy Factor (UEF) of up to 0.98, the EZ98-DV-NG helps reduce standby energy losses commonly associated with storage tank systems while providing dependable residential hot water performance.
