How long does a Navien tankless installation take?

A straightforward replacement of an existing tankless is often a half day. A tank-to-tankless conversion with new gas and venting is usually one full day.

Do I need a permit to install a tankless water heater in San Jose?

Yes. Water heater replacement requires a permit in San Jose and throughout Santa Clara County. We pull it and meet the inspector.

Can I keep my existing gas line?

Sometimes. We calculate the total gas load and the length of the run. If the existing 1/2-inch line can't feed the unit's peak BTU, we upsize it — otherwise you'll chase ignition faults forever.

Do you install customer-supplied Navien units?

We prefer to supply the unit so your warranty is registered correctly and we can stand behind the whole system. Call us and we'll talk through your situation.

How much does a Navien tankless installation cost in San Jose?

It depends on gas sizing, venting path, electrical, and the model you choose. Estimates are free, and we can often quote from photos of your current setup before we ever come out.

Will a tankless really lower my gas bill?

The NPE-2 condensing series is rated up to .96 UEF, versus roughly .60 for a standard atmospheric tank. You also stop paying to keep 50 gallons hot around the clock. Savings are real but depend on your usage.

Where can the unit be mounted?

Garages, exterior walls, utility closets, and side yards all work, subject to venting clearances and freeze protection. We'll pick the location that keeps venting short and service access easy.

Do you add recirculation during installation?

Yes. The NPE-A2 has a built-in recirculation pump and buffer tank. In homes without a dedicated return line, we install a NaviCirc crossover valve under the farthest fixture.

Navien Tankless Water Heater Installation San Jose

Navien Tankless Water Heater Installation in San Jose, CA

A Navien only delivers its rated efficiency and its full warranty when the gas line, venting, and water side are built to spec. That's the whole job — and it's what we do all day in San Jose.

Quick answer

A typical Navien tankless water heater installation in San Jose takes most of one day and includes gas line sizing, stainless or PVC venting, condensate neutralization, isolation valves, and a city permit. Efficient Water Heaters, Inc. installs the NPE-A2, NPE-S2, NCB combi, and NWP500 under CSLB #1008381, with free estimates at (408) 470-0191, available 24/7.

What a correct Navien installation includes

Most of the failing tankless units we're called to didn't fail — they were installed wrong. Here's what a code-compliant install actually requires.

Gas load calculation and line sizing for the unit's full BTU draw, not a guess off the old tank
Sealed combustion venting sized and pitched correctly, with proper termination clearances
Condensate drain with neutralizer so acidic condensate doesn't eat your plumbing
Service isolation valves so the unit can be flushed without cutting pipe
Seismic strapping, correct clearances, and a permit pulled with the City of San Jose
Startup, combustion check, temperature calibration, and warranty registration

Sizing: which Navien is right for your home

Sizing is about simultaneous demand and incoming water temperature, not square footage. In San Jose, groundwater arrives around 55–60°F, which means a well-chosen unit can run near its rated flow.

1–2 bathrooms, no tub-filler: NPE-180S2 or NPE-180A2 territory
3 bathrooms with normal overlap: NPE-240S2 or NPE-240A2
Large homes, soaking tubs, or heavy simultaneous use: NPE-240A2 with recirculation, or a two-unit cascade
Homes that also want space heating from one appliance: NCB combi-boiler
All-electric or heat-pump-mandated projects: NWP500 hybrid heat pump water heater

Sizing: which Navien is right for your home

Replacing a tank with a Navien tankless

Swapping a 40- or 50-gallon tank for a tankless is more than a like-for-like exchange. The gas line usually needs upsizing, the old B-vent gets abandoned or reused for another appliance, and new venting is routed to an approved termination. We handle demo, disposal, the venting path, the gas work, the permit, and the inspection. Most conversions take one full day.

Permits, inspection, and your warranty

Every install we do is permitted and inspected. That protects your homeowner's insurance, your resale disclosure, and your Navien warranty — the manufacturer's long residential coverage assumes a licensed, code-compliant installation. We register the unit for you so coverage starts on day one.

What drives installation cost

We don't publish flat prices because no two San Jose garages are alike. These are the variables that actually move the number, and we'll walk through them with you before any work begins.

What changes the cost of a Navien tankless installation

What changes the cost of a Navien tankless installation
Factor	Why it matters
Gas line size and run length	A tankless draws far more BTU at peak than a tank; an undersized line must be upsized or re-run.
Venting path	A short sidewall termination is simple; a long vertical run through a finished ceiling is not.
Electrical	The unit needs a dedicated receptacle; older garages often need a new circuit.
Water treatment	Hard-water homes benefit from a scale filter or softener loop added at install.
Recirculation	Adding a dedicated return line or a NaviCirc crossover valve for instant hot water.
Condensate handling	Condensing models need a neutralizer and a legal drain point.
Model and capacity	NPE-S2 vs NPE-A2 (built-in recirculation), 180 vs 240 series, or a combi-boiler.
Permit and inspection	City of San Jose permit fees and the inspection visit are included in our scope.

What San Jose customers say

“Had a great experience with the guys at Efficient Water Heaters. Joseph and his employee came out right on time, got to work with no fuss, and a little more than three or four hours later we had a brand new tankless installed in our house. They even swept up the garage cleaner than it was before they got there. Great communication before, during, and afterwards. Would definitely recommend them.”

— Chieze O.

“I asked a lot of questions about tankless. Joseph was quick in responding and the answers were unbiased and helpful. Marco helped us install the water heater. He is efficient, professional, and the job was very well done. Price is fair — I got the best quote comparing with 2 other vendors who have good reviews on Yelp. Highly recommend.”

— Tony C.

“We were in a bind. Had no water and couldn't get ahold of anyone on the weekend. Joseph responded immediately. Scheduled an appointment the next day and gave us a beautiful new tankless hot water heater for the same price as the previous person quoted for a 40-gallon. His work was very nicely done and we are very happy with our new efficient water heater.”

— Celeste G.

Get a free installation estimate

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Frequently asked questions

Efficient Water Heaters, Inc. · Joseph J. Castro, Owner · CSLB #1008381 · (408) 470-0191 · Navien tankless service in San Jose