Description

Who the Navien NPE-240S2 Suits

The NPE-240S2 is a good fit for a home that wants hot water on demand from a compact, wall-hung unit and does not need a built-in recirculation pump. Navien rates it at 5.8 GPM at a 67°F temperature rise, which is the kind of rise cold Midwest groundwater demands in winter, and 11.2 GPM at a 35°F rise in warmer months. GPM at a temperature rise tells you how many fixtures can run at once on the coldest day of the year, which is why sizing matters. As a rough example, 5.8 GPM is about two showers running together; our estimator matches Navien’s figures to your fixture count and incoming water temperature. If your home has long pipe runs and you want hot water at the tap faster, compare the NPE-240A2, which adds Navien’s ComfortFlow buffer tank and pump; the S2 can add recirculation later with an optional NaviCirc valve and an external pump.

Benefits You Will Notice

• Endless hot water on demand. The unit heats water as you use it, so a long shower after a load of laundry does not run cold. Maximum input is 199,900 BTU/h, and the burner modulates down to 13,300 BTU/h for small draws like a hand wash. Turndown is how low the burner can modulate; a wide range reduces short cycling on small draws (Navien rates the NPE-S2 series at up to 15:1).
• 0.96 UEF, ENERGY STAR certified. UEF is the federal efficiency rating for water heaters, and higher is better. The NPE-240S2 is a condensing unit: a second heat exchanger captures heat from the exhaust before it leaves the house, which is why efficiency is this high and why it vents in PVC and needs a condensate drain. Both heat exchangers are stainless steel, and Navien backs the heat exchanger for 15 years on a residential installation with standard or controlled recirculation (warranty details below).
• Space saved. The cabinet is 17.3″ wide by 27.4″ tall by 13.2″ deep and weighs 73 lbs, so it hangs on a wall indoors and frees the floor space a tank used to take. Navien also lists an outdoor wall-hung option, which it recommends for mild climates only.
• Flexible fuel and venting. Runs on natural gas or propane and is field convertible. Navien allows 2″ PVC venting up to 75 feet and a 1/2″ gas line up to 24 feet (subject to local code; the actual run length is confirmed at your estimate), which often means less re-piping in an existing home.
• Simple controls, optional Wi-Fi. The built-in EZNav panel shows temperature and flow and runs self-diagnostics. NaviLink or NaviLink Lite Wi-Fi control is an optional add-on, not built in.

Price and Installation Estimate

Request an installation estimate. GSHA Services, LTD does not publish a package price for the NPE-240S2; we price it as a complete installed package after a short visit or a phone review of your gas line, venting route and water quality. The estimate is free and there is no obligation.

What a standard GSHA tankless replacement installation includes:

• Setting and leveling the new unit
• Water piping changes and new isolation service valves
• Gas piping changes with a new gas valve
• New PVC flue venting
• New condensate drain line and condensate neutralizer kit
• New 150 PSI relief valve, in-line check valve and stainless steel thermal expansion tank
• Electrical connection
• Penguin water heater protection system
• Removal and disposal of the old water heater
• Professional start-up and safety inspection

Your written estimate confirms the exact scope for your home.

What can change the final quote: gas line capacity and length, the venting route and length, where the condensate can drain, water quality treatment for hard water, electrical work, piping changes, permits, accessibility of the installation location, and optional accessories such as NaviLink Wi-Fi or a NaviCirc recirculation kit.

Financing available with approved credit. See our financing page for details.

Request an Installation Estimate  or call (224) 220-3660

Navien NPE-240S2 Specifications

Specification	Navien NPE-240S2
Type	Condensing tankless gas water heater, indoor or outdoor wall-hung
Uniform Energy Factor (UEF)	0.96 (natural gas and propane)
ENERGY STAR	Yes
Input (min – max)	13,300 – 199,900 BTU/h
Flow rate	11.2 GPM at 35°F rise; 8.7 GPM at 45°F rise; 5.8 GPM at 67°F rise; minimum 0.5 GPM
Turndown ratio	Up to 15:1 (Navien NPE-S2 series rating). Turndown is how low the burner can modulate; a wide range reduces short cycling.
Heat exchangers	Dual stainless steel (primary and secondary)
Recirculation	Not built in; optional NaviCirc valve kit (30022965A) plus external pump
Controls	EZNav multi-line control panel, HotButton; NaviLink / NaviLink Lite Wi-Fi optional
Venting	Direct vent; 2″ or 3″ PVC, CPVC, polypropylene or stainless; 2″ PVC up to 75 ft (per Navien; actual run length confirmed at estimate); 0″ clearance to combustibles
Fuel	Natural gas or propane, field convertible; 3/4″ NPT gas inlet; 1/2″ gas pipe capable up to 24 ft
Water connections	3/4″ NPT; 15–150 PSI
Electrical	120 V AC, 60 Hz; max 200 W (350 W with external pump)
Dimensions (W x H x D)	17.3″ x 27.4″ x 13.2″
Weight	73 lbs
Certifications	AHRI 206368362; CSA; NSF Standard 5; Low Lead; SCAQMD 1146.2 low NOx (20 ppm)
Application	Residential (also rated by Navien for commercial use)

Source: Navien NPE-240S2 model page and NPE-S2 series page at navieninc.com. Sound level and 3″ vent length are not published on Navien’s product pages; see Navien product data.

Installation and Warranty

GSHA Services, LTD is a Navien Service Specialist (NSS), an authorized Navien dealer, and is listed on Navien’s installer locator at navieninc.com. Our Navien Level 3 trained technicians install the NPE-240S2 to Navien’s installation manual, which matters because Navien’s warranty requires a licensed installer, a Navien-authorized supply channel and regular maintenance. We install throughout McHenry County and Lake County, IL, and the surrounding Chicago suburbs and southeastern Wisconsin; see our service area.

Navien residential limited warranty (NPE-S2): 1 year labor, 5 years parts and 15 years on the heat exchanger for a residential installation with standard or controlled recirculation. If an external recirculation pump runs continuously without an aquastat or other control, Navien’s uncontrolled-recirculation terms apply: 1 year labor, 3 years parts, 5 years heat exchanger. Full terms: Navien NPE-S2 warranty.

• Proof of purchase is required for warranty service.
• Coverage is void on units bought online or through non-authorized channels, and on units used for space heating only.
• Keep your installation date with your proof of purchase; Navien uses them to set the warranty start.

GSHA Install-Right coverage: on a GSHA tankless installation we add our own 5-year labor and 5-year parts coverage, backed by Navien’s 15-year residential heat exchanger term. GSHA labor coverage is valid only with annual GSHA maintenance, and service by others voids it. GSHA also warrants its water, gas and venting connections for life. The two warranties are separate: Navien’s covers the equipment, GSHA’s covers the installation.

Optional add-ons (compatible with the NPE-240S2 per Navien): NaviCirc recirculation valve kit ($99.60 for the kit; external pump and installation quoted separately), NaviLink Wi-Fi control ($288.43) or NaviLink Lite ($153.55); installation is quoted with your estimate. Ask about them when you request your estimate.

Frequently Asked Questions

How much does a Navien NPE-240S2 cost installed?

GSHA prices the NPE-240S2 as a complete installed package after reviewing your home, so request a free estimate rather than relying on a published number. The quote covers the unit, gas and water piping changes, PVC venting, condensate drain, valves, expansion tank, start-up and removal of the old heater; gas line length, venting route and water treatment are the usual reasons quotes differ between homes.

Is the NPE-240S2 big enough for my house?

For many homes, yes. Navien rates it at 5.8 GPM at a 67°F temperature rise, the rise a Chicago-area winter demands, which is roughly two showers running at once; in summer, when incoming water is warmer, it delivers up to 11.2 GPM at a 35°F rise. Our estimator confirms the size against your fixture count and incoming water temperature.

What is the difference between the NPE-240S2 and the NPE-240A2?

The A2 adds ComfortFlow, a built-in buffer tank and recirculation pump that cut hot-water wait time and smooth temperature at the tap; the S2 leaves those out and carries a slightly higher 0.96 UEF (the A2 is rated 0.95). If you want recirculation on the S2, an optional NaviCirc valve uses your existing pipes when there is no dedicated return line, with an external pump. Ask us to quote both if you are deciding between them.

Why does a condensing tankless unit need PVC venting and a drain?

Because it pulls so much heat out of the exhaust that the exhaust cools and condenses. Cool exhaust can be vented in PVC instead of metal, and the acidic condensate has to be neutralized and drained, which is why a neutralizer kit and drain line are part of every GSHA installation.

Does the NPE-240S2 have Wi-Fi?

Not built in. Navien’s NaviLink and NaviLink Lite Wi-Fi controls are optional accessories that let you adjust temperature and see status from your phone; both are compatible with the NPE-240S2.

What maintenance does it need?

Annual maintenance. Navien’s warranty requires regular maintenance, and GSHA’s 5-year labor coverage requires annual GSHA maintenance; we check water hardness at the estimate and recommend treatment if needed.

Get a Free Navien NPE-240S2 Installation Estimate

Tell us about your home and we will confirm sizing, check gas and venting, and send a written installed-package price with no obligation.

Request an Installation Estimate  or call (224) 220-3660

Compare other Navien tankless models on our Navien water heaters page, including the NPE-210S2, NPE-180S2 and NPE-150S2. Replacing a first-generation NPE-240S? The NPE-240S2 is the closest current Navien equivalent (same series lineage and the same 199,900 BTU/h maximum input). For tank options and other brands, visit our water heater services page.