Navien NPE-240A Premium Condensing Tankless Gas Water Heater Review

Navien has been churning out high-quality condensing tankless water heaters since 2006 and the NPE-240A is proof enough of what they can do. A high-end unit, this model boasts state-of-art technology, backed by efficiency and reliability. Sure, this heater doesn’t come cheap but it is worth every buck it sells for. We take a closer look.


Comfort Flow Technology

The NPE-240A, just like all water heaters by Navien touts the brand-exclusive Comfort Flow technology. Essentially, what this means is that it takes less time for the water to travel between the heat exchanger and the faucet. By extension, this action ensures that the flow rate remains constant, thereby eliminating temperature fluctuation. Put differently, when your water starts to heat, the temperature will remain steady until you switch off your tap or shower head. And that’s not even the best part.

Iconic Flow Rate

The Navien NPE-240A Premium Condensing Tankless Gas Water Heater has a flow rate of, get this, 11.2 gallons per minute at a temperature rise of 45 degrees Fahrenheit. The rate increases to 12.2 gallons per minute when the temperature rise is at 35 degrees Fahrenheit. With such a performance, this is indeed one of the most powerful tankless water heaters by Navien and on the market.

What does this kind of power mean for your needs? Well, this bad boy can heat water for a household with up to 7 bathrooms. It will also cater all for day to day tasks that require hot water. In fact, we reckon that it is one of the best tankless water heaters if you have a large household or live in a suburban-sized apartment building.

On top of that, you can set this unit to heat water instantaneously, a function you won’t find with traditional tank water heaters. In the same breath, you can switch from hot to cold water right away, at the press of a button. Speaking of buttons, we tell you about the NPE-240A user-friendly interface, next.

Highly Responsive Control Panel

The Navien NPE-240A Premium Condensing Tankless Gas Water Heater, despite all it can do, is one of the simplest models to operate. Its interface not only allows you to set the recirculation mode but also comes with a diagnostic button to let you troubleshoot and rectify minor faults automatically. And then there is the master button for cascade operation and one that gives you basic information such as the temperature at which the water is heating.

I particularly love the up and down push buttons that enable you to increase the temperature at 1 degree Fahrenheit in the range of 98 degrees Fahrenheit to 140 degrees Fahrenheit. You can also use a remote control to fine-tune the NPE-240A but it’s an optional accessory.

Ultra Condensing Efficiency

Make no mistake about it – this is a high-performing tankless water heater but that doesn’t mean it will cost you money to run it. In fact, it is quite the opposite. The Navien NPE-240A comes with dual stainless steel exchanger, designed to heat water fast, efficiently for months upon months. And with an energy factor of 0.97, there’s no denying that you’ll save money with this model in comparison to non-condensing units.

… Remember to,

Vent the NPE-240A Properly – To make the most out of this heater, you must vent it in a way that ensures a constant flow of fresh air and exhaust of combustion gases. Be sure to use the 2 inch PVC, PP, ABS of CPVC venting pipes with a length of about 60 ft or150 ft if you use a 3-inch pipe.

Use the Cascading System for More Hot Water – This unit has an integrated control feature that allows you to connect up to 16 units to the Navien Ready-Link communication cable if your demand for hot water is high. And the beauty of it is that you won’t require extra elements.

Take Advantage of the Useful Add-On Features – The NPE-240A is compatible with your home Wi-Fi. That way, you can use your smartphone to control the water temperature, check the status and receive notifications in case of a malfunction.


  • Reliable and long lasting heating operation
  • Supports indoor and outdoor installation
  • Integrated control panel with error display
  • Smart preheating technology
  • A host of safety features


  • Expensive


The Navien NPE-240A Premium Condensing Tankless Gas Water Heater ticks all the boxes a model of its status should. It is powerful and versatile. When used properly, it will serve you for more than 20 years. Be sure to read our maintenance tips to learn how to keep its efficiency at 100%.

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