Description

This Navien model has been discontinued, but GSHA Services continues to service and repair Navien NPE tankless water heaters. If your unit needs repair, contact us to schedule service. If you’re considering replacement, explore the current Navien option below.

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About this model

The NPE-180S was the 150,000 BTU/h model in Navien’s original NPE-S (“NPE-Standard”) line, introduced in 2013. It is a condensing tankless water heater: a second stainless steel heat exchanger captures heat from the exhaust, which is why its efficiency is high and why it uses PVC venting and needs a condensate drain. The “S” models have no built-in buffer tank or recirculation pump, so an external pump was needed for recirculation.

Its 0.97 UEF is the federal efficiency rating for water heaters (higher is better). Hot-water delivery drops as incoming water gets colder: 8.4 GPM at a 35°F temperature rise falls to 4.2 GPM at a 67°F rise, and the 67°F figure is the one that matters in a Midwest winter because it decides how many fixtures can run at once.

The specifications below are the ones Navien published for the NPE-180S. Navien no longer hosts a live spec page for this model, so they come from Navien’s archived model page and QuickFacts page and from the original GSHA listing.

Specification	NPE-180S
Heat input	15,000 – 150,000 BTU/h (natural gas or propane)
Efficiency	0.97 UEF (NG and LP)
ENERGY STAR	Certified (NPE-180S-NG and NPE-180S-LP)
Hot-water flow	8.4 GPM at 35°F rise; 6.5 GPM at 45°F rise; 4.2 GPM at 67°F rise; minimum flow 0.5 GPM
Heat exchangers	Dual stainless steel (primary and secondary)
Venting	Direct vent; 2" or 3" PVC, CPVC or polypropylene; SCH 40 2" venting up to 60 ft; 0" clearance to combustibles
Gas	Natural gas or propane, field convertible; ½" gas pipe capable up to 24 ft
Emissions	Low NOx (20 ppm)
Recirculation	None built in; external pump connection supported
Cascading	Cascading capable
Dimensions	17.3" W x 27.4" H x 13.2" D
Weight	67 lbs
Installation	Indoor or outdoor wall-hung
Application	Residential / commercial (not for space-heating-only use)

Source: Navien’s archived NPE-180S model page (2021) and QuickFacts page (2021), Navien’s 2013 NPE-S press release for the recirculation note, the Navien NPE-S warranty page for the application row, and the original GSHA listing for installation and application.

Turndown ratio, sound level and NaviLink compatibility were not published by Navien for this specific model; see Navien product data if you need them.

Repair and service for this model

Discontinued does not mean your NPE-180S has to be replaced. Navien stopped making the model; it did not stop the unit on your wall from working. GSHA Services, LTD is a Navien Service Specialist (NSS) with Navien Level 3 trained technicians, and we service and repair existing NPE tankless water heaters across McHenry County and Lake County, IL, and the surrounding Chicago suburbs and southeastern Wisconsin.

Common service on first-generation NPE units includes descaling and flushing the heat exchangers, cleaning the inlet filter, checking the condensate drain and neutralizer, and diagnosing error codes. Annual maintenance does more than anything else to keep a condensing tankless unit running, especially where hard water or scale build-up is present.

Navien’s NPE-Standard residential limited warranty for this series is 1 year labor, 5 years parts and 15 years on the heat exchanger for standard or controlled-recirculation installs (units produced on or after January 1, 2016 with uncontrolled recirculation carry 1 / 3 / 5). Coverage depends on when the unit was produced and how long it has been in service (for new construction, Navien counts from when the homeowner took title), so the age of your unit determines what, if anything, is still covered.

See our water heater services page for repair, maintenance and replacement options, or schedule water heater repair online.

Replacement options

Current Navien alternative

Navien does not name a successor for the NPE-180S on its discontinued-products page. The closest current Navien equivalent, based on the same series lineage and the same 150,000 BTU/h maximum input, is the Navien NPE-180S2 condensing tankless water heater.

What changed in the NPE-2 generation, and what it means at home:

• Modulates down to 10,000 BTU/h (the NPE-180S bottomed out at 15,000): steadier temperature at low flows, such as a hand-wash. Navien rates the NPE-S2 series at up to 15:1 turndown.
• 4.3 GPM at a 67°F rise (was 4.2 GPM): essentially the same winter capacity, so it suits the same household.
• 2" PVC venting up to 75 ft (was 60 ft): more flexibility in where the vent can run.
• Dual Venturi gas system and EZNav multi-line control panel: better combustion control and easier setup and diagnostics for the technician.
• Same 17.3" x 27.4" x 13.2" cabinet: usually fits the existing wall spot.
• Rated 0.96 UEF (the NPE-180S was rated 0.97 UEF).

If you want a built-in buffer tank and recirculation pump (ComfortFlow) to cut hot-water wait time and smooth temperature, the NPE-180A2 is the same size class with those features. Ask about it during the estimate.

There is no package price for the NPE-180S2 in our price book, so replacement starts with a free installation estimate. The estimate confirms gas line capacity and length, the venting route, the condensate drain and any water treatment needed, and it is the only way to get an accurate installed price. Financing is available with approved credit; see financing. Compare the full current lineup on our Navien water heaters page.

Frequently asked questions

Is the Navien NPE-180S still made?

No. Navien lists the NPE-180S under NPE-S Series on its discontinued-products page, and its model page now redirects to a downloads-only page. Navien does not publish the discontinuation date.

Can I still get parts and repair for an NPE-180S?

Yes. GSHA Services, LTD repairs existing NPE units, and Navien still keeps a downloads page for the NPE-180S with general NPE documentation. Parts availability for an out-of-production unit can vary by component, so we confirm what is needed during the service visit.

Do I have to replace my NPE-180S because it is discontinued?

No. A discontinued model can keep running for years with proper maintenance. Replacement makes sense when a repair costs more than the unit is worth to you, when parts are no longer available, or when the unit is undersized for how your household uses hot water.

What replaces the Navien NPE-180S?

Navien has not named an official replacement. The closest current model is the NPE-180S2, which has the same 150,000 BTU/h maximum input and the same cabinet size. The NPE-180A2 is the same size with a built-in recirculation pump and buffer tank.

Will a new NPE-2 fit the same venting and gas line?

Often, but not always. The NPE-180S2 has the same cabinet dimensions and uses the same 2" or 3" PVC venting and the same ½" gas pipe allowance up to 24 ft, so many swaps reuse the existing wall location. The estimate visit confirms the venting, gas line and condensate requirements for your home before we quote.

Need service on your NPE-180S?

Whether you want the unit you have repaired or want to talk through a current Navien replacement, GSHA Services, LTD can help. Schedule water heater repair or call (224) 220-3660. We serve homes from our Woodstock and Lake Bluff, IL locations; check our service area.