The Navien NPE-240A2 is a top-performing tankless water heater engineered to provide continuous hot water while maximizing energy efficiency. With a heating capacity of 199,000 BTU and a maximum flow rate of 11.2 gallons per minute (GPM), this model is ideal for households with 4 to 5 occupants or multiple bathrooms that require reliable hot water on demand.
With its combination of efficiency, reliability, and innovative features, the Navien NPE-240A2 offers exceptional value. Homeowners and businesses benefit from consistent hot water, lower utility bills, and peace of mind knowing they are using a trusted, eco-conscious system.
Navien NPE-240A2 Tankless Water Heater is a high-performance, energy-efficient tankless water heater designed to deliver endless hot water while reducing utility costs. With its advanced condensing technology, it offers one of the industry’s highest energy efficiency ratings, making it an excellent choice for both residential and light commercial applications.
Endless Hot Water with High Flow Rate
The NPE-240A2 delivers a consistent supply of hot water, even during peak usage. Whether it’s showers, laundry, or dishwashing running at the same time, this unit is built to keep up without interruptions.
Integrated Recirculation System
Unlike many standard models, this unit comes with a built-in recirculation system. This feature ensures faster hot water delivery while reducing water waste, eliminating the wait time often associated with tankless systems.
Safe and Efficient Direct Venting
Equipped with direct vent technology, the NPE-240A2 expels combustion gases directly outdoors, enhancing safety, efficiency, and indoor air quality. Its wall-mounted design also saves valuable floor space compared to traditional water heaters.
Superior Efficiency with Energy Star® Certification
With a Uniform Energy Factor (UEF) of 0.96, this model is rated as super high efficiency. As an Energy Star-certified water heater, it helps homeowners cut down on utility bills while lowering their carbon footprint.
Durability and Longevity
When properly installed and maintained, the NPE-240A2 is built to last 15 to 20 years. Routine maintenance, such as descaling and flushing, prevents mineral buildup and ensures long-term reliability.
Trusted Navien Quality
Navien is one of the most recognized names in the water heating industry, known for innovation, durability, and comfort-driven solutions for both residential and commercial applications.
| Item | NPE-240A2 | |
|---|---|---|
| Heat Capacity (input) | Natural gas | 13,300 - 199,900 BTU/h (3.9 - 58.57 kWh) |
| Propane | 13,300 - 199,900 BTU/h (3.9 - 58.57 kWh) | |
| Efficiency ratings | UEF (NG & LP) | 0.95 |
| Uef Mx | ||
| Flow rate (DHW) | 35°F temp rise | 11.2 GPM (42.4 l/m) |
| 45°F temp rise | 8.7 GPM (32.9 l/m) | |
| 67°F temp rise | 5.6 GPM (21.2 l/m) | |
| Dimensions | 17.3" W x 27.4" H x 13.2" D (43.9cm W x 69.6cm H x 33.5cm D) | |
| Boiler weight | 77 lbs (34.9 kg) | |
| Installation location | Indoor or outdoor wall-hung | |
| Venting type | Forced draft direct-vent | |
| Ignition | Electronic ignition | |
| Water pressure | 15-150 PSI (1.05-10.55 kg/cm2) | |
| Natural gas supply pressure (from source) | 3.5" WC to 10.5" WC (0.87 kPa to 2.61 kPa) | |
| Propane gas supply pressure (from source) | 8" WC to 13" WC (1.99 kPa to 3.23 kPa) | |
| Natural gas manifold pressure (min-max) | -0.03" WC to -0.96" WC (-0.0075 kPa to -0.24 kPa) | |
| Propane gas manifold pressure (min-max) | -0.02" WC to -0.96" WC (-0.005 kPa to -0.24 kPa) | |
| Minimum flow rate | 0.5 GPM (1.9 l/m), < 0.01 GPM (0.04 l/m) option* | |
| Connection sizes | Cold water inlet | 3/4" |
| Hot water outlet size | 3/4" | |
| Gas inlet | 3/4" | |
| Power Supply | Main supply | 120V AC, 60 Hz |
| Maximum power consumption | 200 W (max 2 A), 350 W (max 4 A) with external pump connected | |
| Materials | Casing | Cold rolled carbon steel |
| Heat exchangers |
Primary heat exchanger: stainless steel Secondary heat exchanger: stainless steel | |
| Venting | Exhaust | 2" or 3" PVC, CPVC, approved polypropylene and stainless steel 2" or 3" special gas vent type BH (Class II, A/B/C) |
| Intake | 2" or 3" PVC, CPVC, approved polypropylene and stainless steel 2" or 3" special gas vent type BH (Class II, A/B/C) | |
| Vent clearances | 0" to combustibles | |
| High elevations | 10,100 feet for both NG or LP gas. Please refer to Installation Manual for details. | |
| Safety Devices | Flame rod, APS, ignition operation detector, water temperature high limit switch, exhaust temperature high limit sensor, power surge fuse, burner high limit fuse, vent installation detector (VID) | |
*Available for NPE-A2 models configured in an optional ComfortFlow® recirculation mode. Energy consumption will increase when the system is configured for recirculation.
Navien reserves the right to change specifications at any time without prior notice.
| Model | Natural Gas | Propane |
|---|---|---|
| NPE-240A2 | 13,300 - 199,900 BTU/h (3.9 - 58.57 kWh) | 13,300 - 199,900 BTU/h (3.9 - 58.57 kWh) |
| Product | Condition | Labor | Parts | Heat Exchanger |
|---|---|---|---|---|
| NPE-A2 Advanced (Residential) | Standard or Controlled Recirculation | 1 Year | 5 Years | 15 Years |
| Uncontrolled Recirculation | 1 Year | 3 Years | 5 Years | |
| NPE-A2 Advanced (Commercial or Combi) | Standard or Controlled Recirculation | 1 Year | 5 Years | 8 Years |
| Uncontrolled Recirculation | 1 Year | 3 Years | 3 Years |
Combi refers to a combination potable water and space heating application. Water heaters cannot be used in space heating only applications.
Controlled-Recirculation: Recirculation the water heater is controlled by either the water heater or an external aquastat.
Uncontrolled-Recirculation: External pumps configured to circulate continuously through the water heater are subject to the uncontrolled recirculation warranty terms. An aquastat is the minimum pump control requirement for DHW or storage tank recirculation in order to maintain the full controlled warranty.
Yes, the NPE-2 can operate with a ½” gas line, provided the line is sized correctly for the system. Keep in mind that factors such as pipe diameter, total run length, and pressure drop all influence proper gas delivery. Always check the National Fuel Gas Code sizing charts to verify that your gas supply meets the unit’s requirements.
No, it doesn’t have to be the first appliance off the meter. The NPE-2 can replace a traditional tank-style heater using your existing gas infrastructure, as long as the line is properly sized and able to deliver enough fuel to the unit.
The NPE-2 supports both 2” and 3” venting:
Approved vent materials include PVC Schedule 40, CPVC Schedule 80, polypropylene, and stainless steel.
Yes. PVC Schedule 40 is approved for use with the NPE-2 condensing tankless water heater. It is also rated for zero-inch clearance to combustible materials, making installation more flexible.
Yes. The NPE-2 includes a built-in digital display and control panel, providing easy access to system settings and operation without the need for a separate remote.
ComfortFlow® combines a buffer tank with a built-in recirculation pump. The buffer tank helps eliminate the “cold water sandwich” effect common in tankless units, while the recirculation pump delivers hot water to fixtures more quickly, reducing both wait times and water waste.
Yes, the NPE-2 can be mounted outdoors when paired with the Navien Outdoor Vent Kit. However, it is best suited for regions with mild climates. Always follow the installation guidelines provided in the manufacturer’s manual.
Yes. The NPE-2 is field convertible. It comes factory-set for natural gas (NG), but can be converted to liquid propane (LP) using the supplied conversion kit.
