Navien NPE‑240S2 Ultra-Efficient Tankless Water Heater (with Professional Installation)

Navien NPE‑240S2 ultra-efficient tankless water heaters provide continuous hot water with ENERGY STAR® performance and low emissions.

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Navien NPE‑240S2 Ultra‑High Efficiency Condensing Tankless Water Heater

The NPE‑240S2 is part of Navien’s NPE‑S2 Series—ultra‑high efficiency condensing tankless water heaters designed for residential or light-commercial installations. All models support indoor or outdoor wall mounting, field gas convertibility, and are ENERGY STAR® certified.

Efficiency:

Uniform Energy Factor (UEF): 0.96 (Natural Gas or Propane)
ENERGY STAR® Certified for high performance and reduced energy costs

Performance:

Heat Input Range: 13,300 – 199,900 BTU/hr
Flow Rates:
- 11.2 GPM @ 35 °F rise
- 8.7 GPM @ 45 °F rise
- 5.8 GPM @ 67 °F rise

Durability & Safety:

Dual stainless steel heat exchangers for corrosion resistance and long service life
Built-in safety features include flame sensor, overheat protection, freeze protection, fan motor rotation detector, and vent blockage detector

Installation & Features:

Indoor or outdoor wall-hung installation with vent lengths up to 75 ft (2″”) or 150 ft (3″”)
Supports ½”” gas piping up to 24 ft for retrofit compatibility
EZNav™ control panel with full text diagnostics and setup wizard
Ready-Link® system allows cascading up to 32 units or common venting up to 12 units

Plus:

Compact dimensions: 17.3″” W × 27.4″” H × 13.2″” D
Low NOx emissions — compliant with SCAQMD Rule 1146.2
Minimum flow rate: 0.5 GPM (operation down to 0.01 GPM with flow control accessories)

Warranty (Residential Installations):

15-Year Limited Warranty on Heat Exchanger (when used without uncontrolled recirculation)
5-Year Limited Warranty on Parts
1-Year Limited Warranty on Labor

Note: Using uncontrolled external recirculation may reduce heat exchanger warranty to 5 years.

Learn more on the official product page:
Navien NPE‑240S2 Product Details

Item	NPE‑240S2
Heat Capacity (Natural Gas)	13,300 – 199,900 BTU/h (3.9 – 58.57 kWh)
Heat Capacity (Propane)	13,300 – 199,900 BTU/h (3.9 – 58.57 kWh)
Efficiency (UEF)	0.96 (NG & LP)
Flow Rate @ 35°F Rise	11.2 GPM (42.4 l/min)
Flow Rate @ 45°F Rise	8.7 GPM (32.9 l/min)
Flow Rate @ 67°F Rise	5.8 GPM (22 l/min)
Dimensions (W x H x D)	17.3″” x 27.4″” x 13.2″” (43.9 cm x 69.6 cm x 33.5 cm)
Unit Weight	73 lbs (33.1 kg)
Installation	Indoor or outdoor wall-hung
Venting Type	Forced draft direct-vent
Ignition	Electronic ignition
Water Pressure Range	15 – 150 PSI (1.05 – 10.55 kg/cm²)
NG Supply Pressure	3.5″” – 10.5″” WC (0.87 – 2.61 kPa)
LP Supply Pressure	8″” – 13″” WC (1.99 – 3.23 kPa)
NG Manifold Pressure	-0.03″” – -0.96″” WC (-0.0075 – -0.24 kPa)
LP Manifold Pressure	-0.02″” – -0.96″” WC (-0.005 – -0.24 kPa)
Minimum Flow Rate	0.5 GPM (1.9 l/min)
Cold Water Inlet Size	3/4″” NPT
Hot Water Outlet Size	3/4″” NPT
Gas Inlet Size	3/4″” NPT
Power Supply	120V AC, 60 Hz
Max Power Consumption	200 W (max 2 A), 350 W (max 4 A with external pump)
Casing Material	Cold rolled carbon steel
Heat Exchangers	Primary: Stainless steel Secondary: Stainless steel
Exhaust Venting	2″” or 3″” PVC, CPVC, polypropylene or stainless steel (Class II, A/B/C)
Intake Venting	2″” or 3″” PVC, CPVC, polypropylene or stainless steel (Class II, A/B/C)
Vent Clearances	0″” to combustibles
High Elevation Limit	Up to 10,100 ft (NG or LP)
Safety Devices	Flame rod, APS, ignition detector, high-limit switches, exhaust sensor, surge fuse, burner fuse, vent installation detector (VID)

Bacon Wrapped Non-Circ Tankless Install – Turn Key Up To 4 Bath (Natural or Propane Convertible) Includes:

Frame to Retrofit
Gas Connection
Sediment Trap
Venting (No Roofer)
Service Kit
Water Ball Valve
Tankless Pan
Expansion Tank
Condensate Neutralizer
Permit and Inspection if Needed
Up To $650 In Rebates
Manufacturer Warranty: 15 Year Heat Exchanger, 5 Years Parts, 1 Year Labor*

*Ongoing membership to our Friends and Family Plan extends Parts and Labor coverage to 15 Years under the Bacon Wrapped No Hassle Warranty.

Note: Roofer not included. Add attic access if installation is above the first floor.