Navien NPE-240A2 Tankless: Master Plumbers Review

Switching from a traditional water heater to a tankless unit, or looking for an upgrade pick that better meets your growing household’s hot water needs? A condensing tankless water heater is the best option for most gas-powered homes- but which product is right for you?

Our team reviewed the Navien NPE-240A2 tankless water heater and compared it to competing tankless systems from Rinnai and Rheem. Overall, we rank the NPE-240A2 as the second best option- it’s best for large homes and multi-unit properties who cascade multiple units. However, poor customer service and stuck check valves are of major concern.

Our Responsible Master Plumber, Steven Smith, spent 13 hours reviewing the Navien NPE tankless series for this review. For an expert insurance perspective, we spoke to Paxten Volbrecht, Director of Agency Operations at Jacobs Insurance Solutions.

We’ll discuss the core features that the Navien NPE-240A2 provides, specifically to natural gas and propane homes. We’ll cover the pros and cons that matter to everyday homeowners, as well as the cost to own and maintain the unit.

Switching to a tankless in Dallas? Call Mother 24/7- our expert technicians will be there within 24 hours for a no-hassle estimate.

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Why You Should Read This Navien Review

At Mother, our licensed plumbers see more tankless water heater units than most homeowners ever do. We install them weekly, repair them when needed, and replace the ones that don’t hold up over time. 

Our plumbers have installed hundreds of tankless units in homes, and dozens of this exact unit.

Our regular use and working knowledge of tankless water heaters- particularly in gas-powered homes- gives us a clear view of which products and features work- and which ones don’t.

Then, we tell you what we learned in simple terms anyone can understand.

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Electric Tankless Systems Stink- We Don’t Review Them

Our Master Plumbers focused solely on natural gas tankless water heaters for this review series. 

We don’t recommend electric tankless water heaters to homeowners. It costs most people far too much to upgrade the electrical infrastructure of their homes to handle the power needed to run an electric tankless system- most users never make their money back on that initial investment.

Refer to our direct comparison guide between gas and electric tankless systems for a detailed breakdown of why we don’t recommend electric units.

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Navien NPE-240A2: The Bottom Line

If you’re living in a large home or own a multi-family property, the NPE-240A2 is an ideal choice for you. Its ability to cascade up to 12 units in one system is unrivaled in ultra high-efficiency units.

The best feature of the Navien is its built-in recirculation pump. Instant hot water is the primary benefit- and the one homeowners care about most. Amp up your energy efficiency by returning and reheating water in your pipes after the system is used. While other competing products offer the built-in pump (some don’t), none are quite as good as the NPE-240A2’s.

The biggest downside? Customer service is poor for homeowners. Since Navien is a direct-to-plumber brand, they want to talk to plumbers on the phone. This makes ordering replacement parts, checking up on warranties and even asking basic maintenance questions nigh impossible for the average user.

We rank the NPE-240A2 just behind the Rinnai RX199iN as best-in-class for ultra high-efficiency tankless units. Since 2023, we’ve received several service calls to replace seals and gaskets in Navien systems- we’ve gotten zero similar calls for Rinnai units.

If you don’t have time to read the full review, here’s a brief summary of things that mattered most to homeowners in our review process:

Setup: Hire a licensed plumber to handle installation, plumbing and venting, and an electrician to handle wiring and load capacity. Otherwise, you’ll need tools on hand to cut steel and copper tubing and PVC, as well as a torch set.

Installation: Install your NPE-240A2 indoors or outdoors- if you’re installing outside, build protective housing and thoroughly insulate the pipes. Most installation errors occur due to blocked venting, either from misalignment or not cutting back your pipe insulation. The unit is designed for wall-mounted installation.

Space Needs: The unit itself is 17.3” wide, 27.4” tall and 13.2” deep. Our plumbers suggest 10-12 inches of clearance on all sides for proper air circulation and easier maintenance access. Keep at least 2 feet away from liquids, shelving and dryer vents.

Venting Needs: Approved materials include Schedule 40 PVC, CPVC, polypropylene and stainless steel. 2” or 3” pipe is needed for single runs, with a max length of 75 feet. Vertical runs need support every 6 feet.

Avoid aftermarket or generic parts. Navien requires approved venting materials- you’ll likely void your warranty by cutting corners.

Performance: NPE-240A2 systems are condensing units. An extra heat exchanger captures waste heat and reuse it, increasing efficiency up to 20%. The NPE-240A2’s uniform energy factor (UEF) is 9.5. It converts 95% of its used energy into hot water- 2% higher than the average high-efficiency gas tankless unit. Make sure to set the unit to Recirc ON.

Intelligence Mode: The NPE-240A2 features an Intelligence Mode which learns your water usage patterns to inform its pre-heating and delivery systems. This is a great idea- similar to smart water monitor and shutoff systems- but some users do note a learning phase of up to a month for this mode.

Digital Display: The EZNav control panel is complete and easy to understand. Check real-time status, set and monitor water temperature, monitor flow rates, and see error codes. There’s a simple color code for troubleshooting (blue = operating, green = stand by, red = error).

Price: The cost of Navien NPE-240A2  tankless units varies by seller. As of this publication, the average price ranges from $1,720-$2,200 without installation. The problem: you can only get them through authorized sellers, usually plumbers who are incentivized to recommend them over other products. 

Warranty: Navien’s warranty offers are complex and often difficult for homeowners to understand. In order to get the best warranty possible, you need recirculation controlled by either the water heater or an external aquastat. If recirculation is uncontrolled, you get less warranty coverage.

Here’s a simplified table of Navien NPE-240A2 warranty offers:

Recommendation: Our Master Plumbers recommend the Navien NPE-240A2 for multi-family dwellings and extremely large homes, as it’s very easy to cascade and “stack” multiple units. Performance is strong, and we like the built-in recirculation pump and buffer tank.

However, we do note mineral scaling issues that cause stuck check valves and damage to gaskets and seals. Warranty coverage is tough to understand, and customer support isn’t very helpful with this. The price point is several hundred dollars higher than our top choice, the Rinnai RX199iN.

Compare the Navien NPE-240A2 with its main rival, the Rinnai RX199iN. Read our Master Plumbers' Review!

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Stats and Analysis, Navien NPE-240A2 Tankless Water Heater

Let’s look at the basics. How does the Navien NPE-240A2 work? Does it earn its high-efficiency label, and does it outperform other high-efficiency models? Does installing a Navien tankless affect your homeowner’s insurance premium?

Learn what our Master Plumbers and insurance industry experts are saying about the NPE-240A2.

Navien NPE-240A2: what’s in the box?

Here’s what we found when we opened a new Navien NPE-240A2  product package:

• Navien NPE-240A2 gas tankless water heater
• Conversion kit (for natural gas to propane)
• Wall mounting bracket
• Tapping screws and anchors (for mounting bracket)
• HotButton controller
• 2” vent termination cap and flange (for venting)
• User manual

Navien NPE-240A2: product specs

Navien NPE-240A2: product features

Insurance benefits and incentives

If you want the best shot at reducing your insurance premium, install your tankless on the first floor of your home. Not only do you avoid the flood risk of a tank full of water, you avoid second-story leaks ruining your ceilings and first-floor walls.

“[Carriers] don’t want a tank,” says Paxten Volbrecht, Director of Agency Operations for Jacobs Insurance Solutions. “If a tank is going to burst, that is a lot of water coming out at one period of tank versus a tankless. Preferred customers are going to be ones that have… tankless heaters.”

In terms of insurance benefits, Paxten says there’s no difference between installing a gas or electric tankless water heater. Risk mitigation is purely about having no storage tank.

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Our Master Plumber reviews the Navien NPE-240A2

We spoke to our Responsible Master Plumber, Steven Smith, about his hands-on experience testing, installing and repairing the Navien NPE-240A2 tankless water heater. Steven has personally installed over a dozen NPE-240A2 units in homes.

“The Navien’s going to cost you more than the high-efficiency Rinnai (RX199iN),” Steven says. “It’s a good unit. But it’s not as good as the Rinnai.”

Steven’s main point of comparison isn’t in the purchased product or its installation- it’s in repairs. “In the last two years, I haven’t had a single call to repair a Rinnai unit,” he says. “I’ve been out to fix several Naviens, usually due to worn out gaskets and O-rings.”

Scale buildup seems to cause particular havoc in Navien systems. Steven showed concern about the frequency of gasket replacement and stuck check valves in their units.

On a positive note, Steven says the built-in recirculation pump is “great” and the buffer tank performs well. He also notes that Navien units are ideal for multi-unit scenarios, especially condo complexes.

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What It’s Like to Live With the Navien NPE-240A2 Tankless

It’s great to get industry perspectives from Master Plumbers and insurance experts. It’s just as important to see how a tankless water heater performs in real-world scenarios- directly from the homeowners who purchase and own the device.

Most homeowners who call us about the NPE-240A2 are scheduling annual descaling maintenance or dealing with a stuck check valve.

We also analyzed 38 customer reviews of the Navien product we verified to be authentic (no bots, no fake reviews, no paid reviews).

Here’s what people are saying about the Rinnai RX199iN gas tankless water heater:

Real-world pros and cons of ownership

Our team sought out feedback from Navien NPE series owners that offered brand-specific insights. This allows you to see the unique benefits of this tankless compared to other devices.

Pros of the Navien NPE-240A2

• High volume capacity. The unit’s flow rate (11.2 gallons per minute, or GPM) means you get 11.2 gallons of hot water every minute. In “real world” terms, that’s 4 showers and a dishwasher running smoothly at once.
• Ultra-high efficiency. Navien’s ComfortFlow system, with built-in recirculation and buffer tank, means less water waste and good energy savings.
• Condensing unit. Condensing gas tankless water heaters are superior- they’re 20% more energy efficient than non-condensing models. 
• Easy to “cascade units”. Navien makes it easy to install and operate multiple NPC tankless units in one system. Use a common vent for up to 12 units.
• Built-in recirculation pump. Part of the NPE-240A2’s higher price point is due to the built-in recirc pump, which boosts efficiency and reduces hot water delivery delays.
• Buffer tank. Not every tankless comes with one. While it seems redundant to have a “tank” on your tankless, some homeowners do like the efficiency benefits.
• Two stainless steel heat exchangers. You may have some long-haul issues with internal components, but the heat exchangers won’t likely be one.
• $600 tax credit. Take advantage of the EnergyStar tax credit for installing a tankless water heater in your home.
• We like the HotButton control panel. Spring for this add-on. A single push button activates on-demand hot water recirculation- less waiting for the shower to heat up.
• Excellent lifespan. With annual descaling and proper maintenance, expect your NPE-240A2 to last 15 to 20+ years from date of installation.

Cons of the Navien NPE-240A2

• Price. Of the three major 11.1-11.2 GPM flow rate condensing tankless units (Navien, Rinnai and Rheem), the average price point of the NPE-240A2 is highest.
• You have to buy one through a plumber. Navien products are sold by approved licensed plumbers only. We find this often incentivizes plumbers to sell Navien instead of a superior product.
• Frustrating customer service. Online reviewers note issues with Navien’s customer service, like arguments over warranty claims and authorized vs. unauthorized dealers.
• Stuck check valves. The most common complaint about NPE-240A2 owners. An internal flapper or valve is stuck open or closed, often due to mineral scaling.
• Temperamental flow sensors. Scale buildup tends to interfere with Navien flow sensors more easily than Rinnai units, making annual descaling more critical.
• Humidifiers can cause issues. Devices with low-flow properties (like humidifiers) cause rapid bursts of hot water delivery instead of consistent performance. This is called “short cycling”.

Replacing your water heater with a tankless? Dive deeper into the pros and cons of switching in our updated guide!

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What real homeowners say about the Navien NPE-240A2

We found 57 helpful reviews from homeowners who purchased and installed the Navien NPE-240A2 tankless water heater in their natural gas or propane-powered homes. Their insights range from recirculation performance to installation factors, customer service to sourcing replacement parts.

It’s difficult to source reliable reviews, as Navien units are not generally available in retail stores like Home Depot. As such, many reviews appear on Reddit or professional forums. 

There were a higher-than-average number of Navien product reviews on Reddit from licensed plumbers rather than customers.

⭐⭐⭐⭐⭐ “I have the 240A. I've never timed the hot water, but its something I should do. I think you'll be happy with Navien. The installation would be a huge performance factor here, since the 240A has a return loop in the hot supply line. The distance from the heater to fixture will affect the wait time. Pipe insulation will be a factor as well. I'm new to tankless, with only a few winter months using it. My observation, if its super cold outside, the wait time is longer.” – Verified Owner via Reddit

⭐⭐⭐⭐”I have a Navien 240A and use the external circulation feature. My plumber installed a loop to cold and a NaviCirc device under farthest sink. It should solve any cold water sandwich problems. The 240A’s internal recirculator does a fine job. It’s worth it to save a couple seconds multiple times a day.” – Verified Owner via Reddit

⭐⭐ “Buy anything but Navien. I own two of their units. One of them for domestic hot water and the other for heat. One of the units didn't last 3 years before developing a leak. Their customer service is atrocious. They want you to contact a dealer.” – Verified Owner via Reddit 

We also reviewed internal data from installation and repair service calls our customers made about Navien tankless water heaters. These are the 3 most common critiques of the products:

1. Customer service. One reviewer called their experience with Navien customer support “deeply frustrating”. Others report being hung up on during warranty disputes. Overall, Navien has a pretty terrible 1.13 customer rating with the BBB.
2. Check valve problems. Scale buildup affects the NPE-240A2’s check valve more than other internal components- there’s a decent chance yours will be stuck at least once.
3. Gasket and seal wear and tear. If something’s “going to go” in your Navien, it will be a gasket or seal. Our team has replaced several O-rings, seals and gaskets in Navien tankless units this year.

Purchase and Installation Costs

In this section, we’ll cover the true overall cost of the Navien NPE-240A2 tankless unit- not just the purchase price, but the cost to install and repair the system.

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How much does the Navien NPE-240A2 cost?

As of this publication, the average cost to purchase the Navien NPE-240A2 gas tankless water heater ranges from $1,720-$2,200 without installation.

These products are for sale through Navien-approved dealers, not retail. This causes price inflation- plus it makes plumbers more likely to recommend Navien products to customers who are better suited to other devices. We don’t like that, because it leads to some homeowners not getting the best possible product for their needs. 

The price point is $100-$300 higher than the Rinnai RX199iN and $50-80 more expensive than the Rheem IKONIC 11.2.

Is the NPE-240A2 the right size for your home? If you have a small household or 5+ family members, use our quick guide to find the proper size for your tankless.

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How much does it cost to install the Navien NPE-240A2?

It costs between $6,300-$12,300 all-in to install the NPE-240A2. This includes purchase price, installation labor and the cost of upsize the necessary gas lines and venting.

Expect to pay more to install a tankless water heater than a conventional tank. Tankless units are plumbed from below, which is more labor-intensive than traditional water heaters (which are plumbed from above).

These are the 3 key drivers of tankless water heater installation costs:

1. Installation upgrades and upsizing. If you’re installing multiple units, or units that require more complex gas, electrical and venting, expect to pay more.
2. Labor. Labor costs account for a bulk of your installation.
3. Product selection. Ultra high-efficiency gas tankless water heater products range in price from $1,400-2,000. 

Why you need a licensed plumber to install a tankless water heater

The only homeowners who should attempt to install tankless water heaters are licensed plumbers. Otherwise, hire a licensed plumber as well as an electrician for proper load calculations and wiring compliance.

Navien customer service is somewhat notorious for being difficult regarding product warranties. It’s simple for the manufacturer to reject your warranty if you self-install- they prefer licensed techs with experience and training on Navien devices.

Your insurance provider may also request proof of licensed installation in order to convey any benefits or premium incentives related to putting a tankless in your home.

Navien NPE-240A2 Gas Tankless: Our Plumbers’ Conclusions

The ideal customer for the Navien NPE-240A2 tankless water heater is an owner of a very large home, or a multi-family dwelling. The ability to cascade units, plus the built-in recirculation pump and buffer tank, make it a strong choice for larger properties.

The HotButton control panel is the best “extra” for the device. Use a push button to control recirculation when you want it- not just when the system’s off. We also really like the simplicity of the digital display- it’s very easy to check system status and water temperatures.

While the NPE-240A2’s overall performance is roughly equal to the Rinnai RX199iN, we can’t recommend it over the Rinnai product. Navien’s underwhelming customer service reputation, plus more frequent calls for gasket, seal and check valve repairs, make it our 2nd-best option for ultra high-efficiency tankless systems in natural gas and propane homes.

Dallas residents: want to install a Navien tankless? Call Mother 24/7- our licensed plumbing experts install our top brand with precision and confidence.

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