• Which Navien is right for me?
• Compare tankless models
• Cost and what’s included
• Combi-boilers and boilers
• Own an older NPE?
• Warranty
• FAQ

Which Navien is right for your home?

The Navien NPE-240A2 tankless water heater is installed from $6,148.43 (NPE-240A2, natural gas) as a complete installed package. Every other tankless model on this page is quoted after a free in-home estimate. Request a free installation estimate or call (224) 220-3660.

Which Navien tankless water heater is right for your home

Every current Navien NPE-2 tankless water heater is a condensing unit: a second stainless steel heat exchanger captures heat from the exhaust before it leaves the house. That is why the efficiency ratings are high, and it is also why the unit vents in PVC pipe and needs a condensate drain. All seven models can be wall-hung indoors or outdoors, run on natural gas or propane, and use dual stainless steel heat exchangers. The choice comes down to two questions: do you want built-in recirculation, and how much hot water do you need at once?

NPE-A2: built-in ComfortFlow recirculation

The NPE-A2 models (NPE-240A2, NPE-210A2, NPE-180A2) include Navien’s ComfortFlow system: a small buffer tank and a recirculation pump inside the cabinet. In practice that means less waiting at the faucet for hot water and steadier temperatures when someone turns a second tap on or off. It suits larger homes, long pipe runs, and households that want hot water quickly at every fixture. All three A2 sizes are rated 0.95 UEF.

NPE-S2: the standard condensing tankless

The NPE-S2 models (NPE-240S2, NPE-210S2, NPE-180S2, NPE-150S2) use the same condensing design and controls without the internal pump and buffer tank. The 180, 210 and 240 sizes are rated 0.96 UEF; the compact NPE-150S2 is rated 0.93. If you want faster hot water later without a dedicated return line, a NaviCirc valve ($99.60 from our price book, plus an external pump) can recirculate through the existing pipes; Navien lists NaviCirc as an optional accessory for the S2 series.

Sizing: max input and flow at a temperature rise

UEF (Uniform Energy Factor) is the federal efficiency rating for water heaters; higher is better. Flow is rated in gallons per minute (GPM) at a given temperature rise, which is how much the unit has to warm the incoming water. In a northern Illinois winter the incoming water is cold, so the flow at Navien’s 67°F-rise rating point is the practical planning number: it tells you how many showers and appliances can run at the same time.

• NPE-240A2 / NPE-240S2: 199,900 BTU/h max input; 5.6 / 5.8 GPM at a 67°F rise
• NPE-210A2 / NPE-210S2: 180,000 BTU/h; 5.1 / 5.3 GPM at a 67°F rise
• NPE-180A2 / NPE-180S2: 150,000 BTU/h; 4.3 GPM at a 67°F rise
• NPE-150S2: 120,000 BTU/h; 3.4 GPM at a 67°F rise

We confirm the size during the free estimate by counting fixtures and checking your gas supply.

Optional add-ons where Navien confirms compatibility: NaviLink Wi-Fi control ($288.43) or NaviLink Lite ($153.55) let you monitor and adjust the water heater from a phone; NaviCirc ($99.60, plus an external pump) adds recirculation to an NPE-S2 without a return line, and the NPE-240A2 installed package already includes the recirculation valve kit. Wi-Fi is an accessory on the NPE-2 line, not built in.

Compare current Navien tankless models

The table below lists the seven current NPE-2 models with the maximum input, UEF and flow rates Navien publishes on each model page. Only the NPE-240A2 has a published installed package; every other size is quoted after a free estimate. Follow the model links for full specifications, installation scope and warranty details.

Specifications are from Navien’s model pages at navieninc.com. All models are ENERGY STAR certified except the NPE-150S2, which Navien lists as not certified. Navien states a turndown ratio of up to 15:1 for the NPE-2 series, so the burner can run very low when only one tap is open.

What a Navien tankless installation costs and what’s included

The Navien NPE-240A2 is installed from $6,148.43 (NPE-240A2, natural gas). That is a complete installed package from our price book, not an equipment-only figure. A standard tankless installation includes:

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

Other NPE-2 sizes, and propane installations, do not have a published package price; we quote them after a free in-home estimate. What can change the final quote on any model: gas line capacity and length, the venting route and length, where the condensate can drain, water quality treatment, electrical work, piping changes, permits, accessories such as NaviLink or NaviCirc, and how accessible the installation location is. The estimate is free. Financing is available with approved credit.

Request a free Navien installation estimate or call (224) 220-3660.

Navien combi-boilers and boilers

If your home is heated with radiators, baseboard or in-floor tubing, Navien also makes the boiler. A combi-boiler is one wall-hung unit that handles both home heating and domestic hot water, replacing a separate boiler and water heater and freeing up floor space in the mechanical room. The NCB-H series (five sizes, 60,000 to 150,000 BTU/h heating) delivers 4.1 to 5.4 GPM of hot water at a 70°F rise depending on size; both models in the larger fire-tube NFC-H series (175,000 and 199,900 BTU/h heating) deliver 5.4 GPM at a 70°F rise.

A heating-only boiler is the right choice when you already have a water heater you want to keep, or when you pair the boiler with an indirect tank. The NHB-H series covers 55,000 to 150,000 BTU/h in a compact cabinet, and the NFB-H series adds Navien’s ASME-certified stainless steel fire-tube heat exchanger for larger loads of 175,000 and 199,900 BTU/h. AFUE is the heating efficiency rating; every NCB-H, NFC-H, NHB-H and NFB-H model is rated 95% AFUE. Turndown ratio is how low the burner can modulate; it ranges from 5.5:1 to 15:1 by model, and a higher ratio means the burner can run lower for longer instead of short cycling on mild days.

The NPF hydro furnace is different: it is a forced-air furnace that heats water in a sealed internal loop and blows air across a coil, so a home with ductwork can get Navien’s 97% AFUE modulating burner (15 to 100%) and variable-speed ECM airflow; it can also pair with an AC coil or a heat pump. Full details, model-by-model prices and the installation scope for each series are on our Navien boilers page, part of our boiler installation services.

Individual model pages:

• NCB-H combi-boilers: NCB-190/060H, NCB-190/080H, NCB-240/110H, NCB-240/130H, NCB-250/150H
• NFC-H fire-tube combi-boilers: NFC-250/175H, NFC-250/200H
• NHB-H heating boilers: NHB-55H, NHB-80H, NHB-110H, NHB-150H
• NFB-H fire-tube heating boilers: NFB-175H, NFB-200H
• NPF hydro furnaces: NPF700-060H3BH, NPF700-100H5CH, NPF700-100U5CH

Combi-boiler and boiler prices are complete installed packages; the standard scope for each series is listed on the Navien boilers page, and the estimate is free.

Already own a first-generation Navien NPE?

Navien has discontinued the first-generation NPE tankless line. Discontinued does not mean your unit has to be replaced. GSHA Services, LTD, as a Navien Service Specialist, services and repairs existing NPE units, including maintenance and repair.

If you do decide to replace, the closest current Navien alternative for each size is the NPE-2 model with the same number:

Navien does not name official successors on its discontinued-products page, so we present these as the closest current equivalents.

Schedule Navien water heater repair or call (224) 220-3660.

Navien warranty and GSHA Install-Right coverage

Navien’s limited warranty and GSHA’s Install-Right coverage are two separate things. Navien’s residential limited warranty terms, as published on navieninc.com:

• NPE-2 tankless (NPE-A2 and NPE-S2), standard or controlled recirculation: 1-year labor, 5-year parts, 15-year heat exchanger. With uncontrolled recirculation (an external pump running continuously without an aquastat) the terms drop to 1 / 3 / 5 years.
• NCB-H and NFC-H combi-boilers, single-family residential: 1-year labor, 5-year parts, 10-year heat exchanger.
• NHB-H boilers, single-family residential: 1-year labor, 5-year parts, heat exchanger 10 years in full, then pro-rated through year 15.
• NFB-H boilers, single-family residential: 1-year labor, 5-year parts, heat exchanger 12 years in full, then pro-rated through year 15.
• NPF hydro furnaces, residential, registered online within 60 days: 1-year labor, 10-year parts, limited lifetime combustion heat exchanger; if not registered, 1 / 5 / 20 years.

Navien’s warranty runs from the date of original installation, and the homeowner or installer must provide that date (with proof on request) to Navien. Units bought through the internet or e-commerce channels, or installed by a non-licensed installer, are not covered.

GSHA’s Install-Right coverage is added on top of Navien’s terms when we install the equipment:

• Tankless and combi-boiler packages: 5-year parts and 5-year labor coverage
• Boiler packages: 10-year parts and 10-year labor coverage

GSHA labor coverage is valid only with annual GSHA maintenance; service by others voids it. Tankless packages also carry lifetime warranties on the water, gas and venting connections we make.

Frequently asked questions about Navien water heaters

Does GSHA Services install Navien water heaters in my city?

Yes, if you are in McHenry County or Lake County, Illinois, the northern or western Chicago suburbs, or southeastern Wisconsin. Check the service-area page for the full ZIP and city list, or call (224) 220-3660 to confirm your address.

Is GSHA a Navien Service Specialist?

Yes. GSHA Services, LTD was approved as a Navien Service Specialist (NSS) on June 30, 2026, is listed on Navien’s installer locator at navieninc.com, and has Navien Level 3 trained technicians.

How much does a Navien tankless water heater cost installed?

The Navien NPE-240A2 is installed from $6,148.43 (natural gas) as a complete package that includes venting, gas and water piping modifications, condensate handling, a thermal expansion tank, a NaviCirc valve kit, removal of the old heater and start-up. Other NPE-2 sizes and propane installations are quoted after a free estimate, and the final price depends on gas line capacity, venting route, condensate drain, water quality, electrical, permits and accessories.

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

The NPE-A2 has ComfortFlow, a built-in buffer tank and recirculation pump, and the NPE-S2 does not. ComfortFlow shortens the wait for hot water and smooths temperature swings; the S2 is the same condensing water heater without the pump and tank, rated 0.96 UEF on the 180, 210 and 240 sizes compared with 0.95 on the A2, and it can add recirculation later with a NaviCirc valve and an external pump.

Do I need a bigger gas line for a tankless water heater?

Sometimes. A tankless water heater draws far more gas while it runs than a tank heater, up to 199,900 BTU/h on the NPE-240 sizes, so the existing line may need to be enlarged or rerouted. Navien states the NPE-240A2 can run on a 1/2-inch gas line up to 24 feet; we verify gas line sizing, length and regulator capacity during the free estimate.

Is my Navien NPE-240A (first generation) discontinued, and can it still be repaired?

Yes, Navien lists the NPE-240A as discontinued, and yes, it can still be repaired. GSHA Services, as a Navien Service Specialist, services and repairs first-generation NPE units; discontinued does not mean you have to replace a working water heater. If you do replace it, the closest current Navien alternative is the NPE-240A2.

What maintenance does a Navien tankless need to keep the warranty?

Plan on annual maintenance, including a flush of the heat exchanger, especially where water is hard. Scale build-up reduces efficiency, and Navien’s warranty excludes damage from hard water deposits. GSHA’s Install-Right labor coverage is valid only with annual GSHA maintenance; service by others voids it. Navien’s own warranty also requires that the installation date be provided to Navien and that the unit was installed by a licensed installer and not bought online.

Request a free Navien installation estimate

We will inspect your current water heater or boiler, confirm gas and venting requirements, and size the right Navien model for your home. Book online or call (224) 220-3660. See also our water heater services and water heater installation pages.

Recent Navien installations by GSHA Services

Navien Installation and Repair Service Areas

GSHA Services, LTD installs Navien tankless water heaters, combi-boilers and boilers and provides service and repair in McHenry County and Lake County, Illinois, and surrounding communities, including Woodstock, McHenry, Crystal Lake, Algonquin, Huntley, Barrington, Lake Zurich, Libertyville, Lake Bluff, Lake Forest, Gurnee, Waukegan and Grayslake, as well as the northern and western Chicago suburbs and southeastern Wisconsin. We also service and repair existing Navien NPE units. Explore our service areas or contact us to confirm availability at your address.

• McHenry County, IL: Woodstock, McHenry, Crystal Lake, Cary, Algonquin, Lake in the Hills, Huntley, Harvard, Marengo
• Lake County, IL: Lake Bluff, Lake Forest, Libertyville, Mundelein, Vernon Hills, Gurnee, Waukegan, Grayslake, Antioch, Lake Zurich, Wauconda, Barrington
• Northern and western Chicago suburbs: Arlington Heights, Palatine, Schaumburg, Elgin, Naperville
• Southeastern Wisconsin: Kenosha, Racine, Lake Geneva, Burlington, Delavan, Waukesha

About GSHA Services, LTD

GSHA Services, LTD is a family-owned heating, cooling and plumbing contractor that has served northern Illinois and southeastern Wisconsin since 2002. We install and service Navien tankless water heaters, combi-boilers and boilers from two locations.

• Headquarters: 1257 Cobblestone Way, Suite A, Woodstock, IL 60098
• Lake County office: 11 N Skokie Hwy, Suite 111C, Lake Bluff, IL 60044
• Phone: (224) 220-3660
• Email: info@gshaservices.com
• Navien credentials: Navien Service Specialist (NSS), approved June 30, 2026; listed on Navien’s installer locator at navieninc.com; Navien Level 3 trained technicians
• Online booking: Book a free estimate or service call

Read customer reviews on Google, the Better Business Bureau, Yelp (Woodstock), Yelp (Lake Bluff), Angi and Facebook.