NPE-2 condensing tankless series
The NPE-A2 and NPE-S2 run dual stainless-steel heat exchangers and hit up to 0.96 uniform energy factor — condensing efficiency that reclaims heat a standard unit sends up the flue.
Tankless water heaters · Installed & serviced
Navien in Eastern Iowa
Endless hot water — if it's installed and maintained for Eastern Iowa's water.
Navien's NPE-2 condensing tankless series is what we install when a household wants endless hot water and floor space back. The honest catch: Navien's own manual classifies anything over 12 grains per gallon as 'extremely hard' — and Marion runs 18–20. Around here a Navien needs softened water or scheduled descaling, and we set every install up for both.
Prefer to type? Text us at (319) 377-2809 — same-day service for most repairs and free estimates on work over $500.
The company
Who makes it
KD Navien, founded in Korea in 1978, was Asia's first maker of condensing boilers; its North American arm (Navien Inc., Irvine, California) has grown into the top-selling condensing tankless brand on the continent.
Source: Navien Inc. — company overview
What we install from Navien
ComfortFlow recirculation (A2 models)
The A2 builds in a recirculation pump and small buffer tank, killing the 'cold water sandwich' and cutting the wait for hot water at far fixtures.
Compact, wall-hung install
A tankless frees the floor space a 50-gallon tank occupies — a real perk in the mechanical corners of older Marion and Cedar Rapids basements.
Navien × Eastern Iowa
Why the local water changes the answer
This is the brand where our water-quality data matters most. Navien's installation manual tops out its water-hardness chart at 12 grains per gallon ('extremely hard') and calls for a softener and more frequent descaling from 9 gpg up. Marion at 18–20 gpg and Hiawatha at 14–20 are literally off the chart — an unprotected tankless here can scale its heat exchanger inside a year. We install isolation valves on every unit, recommend softening in the very-hard towns, and offer annual descaling service.
Source: Navien NPE-2 installation & operation manual (water quality section)
Your town's number matters
Marion runs 18–20 grains per gallon; Cedar Rapids softens at the plant; the well towns are test-first. We compiled the verified hardness for all 15 towns we serve.
Warranty & workmanship
What the warranty actually says
Manufacturer coverage
Residential NPE units installed by a properly licensed plumber carry a 15-year limited warranty on the heat exchangers, 5 years on parts and 1 year on labor. Navien's terms are strict: DIY installs and uncontrolled recirculation setups cut or void coverage — the warranty is written around professional installation.
Why a pro install protects it
Navien's warranty explicitly requires installation by a properly licensed plumber or contractor — gas sizing, condensate handling, venting and water treatment all have to be right. Gas work in Iowa also legally requires licensed professionals under Iowa Code chapter 105. A tankless is a great machine installed correctly and an expensive mistake installed casually.
Put it in your house
Navien services from Hanna
Tankless water heater installation Navien NPE, installed & permitted
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Tankless water heater repair Descaling, error codes, no-hot-water
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Water softener installation The protection a tankless needs here
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Gas line installation Upsizing for tankless demand
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Do the homework first
Good questions
Answers before you call.
Still wondering about something specific? We’re happy to talk it through — no obligation.
Will a tankless water heater work with Marion's hard water?
Yes — with protection. Navien's manual classifies water over 12 grains per gallon as extremely hard and Marion runs 18–20, so we pair tankless installs here with a water softener or a firm descaling schedule (we recommend annually, and Navien suggests even more often in unsoftened very hard water). Skipping both is how heat exchangers die young.
Is a Navien tankless worth it over a tank?
If your household runs out of hot water, values floor space, or plans to stay put for years — often yes: endless hot water and up to 0.96 UEF efficiency. If your tank meets your needs and your budget is tight, a quality tank is the honest answer. Our cost guide compares both installed.
What maintenance does a Navien need here?
An annual service: descale the heat exchanger through the isolation valves, clean the inlet screen and air filter, and check the condensate line. On softened water the interval stretches; on unsoftened Marion or Hiawatha water it should not be skipped.
What does a tankless conversion cost with Hanna?
A tankless conversion is a bigger ticket than a tank swap because of venting, gas-line and water-line work — so we start with a free estimate (free on work over $500) and an hourly, no-quota price you understand before we begin.
Sources
- Navien — NPE series warranty (15-yr heat exchanger / 5-yr parts / 1-yr labor) (2026)
- Navien — NPE-240A2 product page (0.96 UEF, dual stainless heat exchangers) (2026)
- Navien — NPE-2 installation & operation manual (hardness chart, descaling) (2026)
Compiled July 2026 from manufacturer pages and warranty documents. Manufacturers revise terms — always confirm the current warranty for your exact model, or ask us and we'll pull it for you.
One more thing
Ready for Navien — or a straight answer about it?
One call gets a licensed Hanna tech who installs Navien every week — hourly pricing you understand before we arrive, free estimates on work over $500. Call or text (319) 377-2809.
The Hanna crew — 22 local pros, hourly paid, no quotas.
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(319) 377-2809
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