Noritz 6.6 GPM 120,000 BTU Residential Natural Gas EZTR 40 Gallon Tank Replacement Condensing Tankless Water Heater (.87 UEF)

The Noritz EZTR40-NG EZTR Series 6.6 GPM 120,000 BTU Residential Natural Gas Condensing Tankless Water Heater is specifically designed to simplify the replacement of traditional 40-gallon tank water heaters while providing reliable, on-demand hot water. Featuring a high-efficiency 0.87 UEF condensing design, the EZTR40-NG heats water only when needed, helping reduce energy waste associated with conventional storage tank water heaters.

Designed with top-mounted water connections, the EZTR Series helps streamline retrofit installations by aligning with many existing tank water heater plumbing configurations. With a 120,000 BTU input and up to 6.6 GPM of hot water delivery, the EZTR40-NG is an ideal replacement solution for many 40-gallon natural gas tank water heaters, providing dependable hot water performance while saving valuable floor space.

Product Features:

• 120,000 BTU Input: Provides powerful natural gas heating capacity to deliver continuous hot water on demand.
• Up to 6.6 GPM Flow Rate: Supplies hot water for multiple fixtures, such as showers, sinks, and appliances, depending on incoming water temperature and household hot water demand.
• 0.87 UEF Condensing Efficiency: High-efficiency technology helps capture more heat from the combustion process, reducing energy loss and improving overall performance.
• Designed to Replace 40-Gallon Tank Water Heaters: The EZTR40-NG is engineered specifically for tank replacement applications, helping simplify installation when upgrading from a traditional storage tank water heater.
• Top-Mounted Water Connections: The unique connection layout helps make retrofit installations easier by allowing existing tank water heater plumbing connections to be reused in many applications.
• Indoor Installation: Designed for indoor installation with the included flexible venting system for approved tank replacement applications.
• Flexible Venting Design: The EZTR40-NG uses flexible venting designed specifically for tank replacement installations and cannot be converted for use with PVC or other rigid plastic venting.
• Compact Wall-Mounted Design: Saves valuable floor space compared to traditional 40-gallon storage tanks while providing continuous hot water.
• Wi-Fi Compatible: Allows connection with compatible Noritz accessories for enhanced monitoring and control capabilities.

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 interrupting water service throughout the entire home.

Isolation valves are especially useful for tankless water heaters because routine maintenance helps protect efficiency and extend the life of the heat exchanger. Over time, mineral buildup can accumulate inside the unit, especially in areas with hard water. Isolation valves make flushing and maintenance easier for homeowners and service professionals.

Short vs. Long Isolation Valve Kit

For this Noritz EZTR40-NG tankless water heater, you only need to select one isolation valve kit based on your installation requirements.

• IK-WV-200-5-TH-S Short Isolation Valve Kit: A compact valve kit designed for installations where space is limited or shorter plumbing connections are 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 desired.

Both valve kits include 3/4" threaded isolation valves and a lead-free pressure relief valve. The correct selection depends on your available installation space, plumbing layout, and service accessibility preferences.

Understanding Tankless Water Heater Sizing

Unlike traditional storage 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 incoming groundwater.

When sizing a tankless water heater, always consider your winter groundwater temperature, since colder incoming water requires more heating capacity. As the required temperature rise increases, the available flow rate of the unit decreases.

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 the EZTR40-NG can produce at your required temperature rise. This will help determine if the unit is properly sized for your home's showers, faucets, appliances, and other hot water needs.

Warranty

This product includes a manufacturer's limited residential warranty, including up to 12 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.

A Modern Solution for Today's Homes

The Noritz EZTR40-NG combines energy-saving technology, continuous hot water performance, and installation-friendly design in one compact package. Whether you're replacing an aging tank water heater or looking to improve your home's efficiency, this tankless solution delivers comfort, convenience, and value for years to come.