Tankless Heater Pros ○ Licensed Plumber & Contractor ○ TN #81430

Knoxville’s only tankless‑only specialist

Tankless Water Heater Replacement

When your tankless water heater fails, you don’t have time for guesswork. Tankless Heater Pros is Knoxville’s only tankless‑only installation and replacement company — you get a specialist, not a general plumber trying to “figure it out.” Unlike most, we are certified to replace all major brands, including: Navien, Rinnai, Noritz, Rheem, Bosch, Takagi, and more.

Built for Better Hot Water

Why Homeowners Choose Tankless Heater Pros.

Enjoy endless hot water, lower energy costs, and expert craftsmanship backed by Knoxville's dedicated tankless specialists.

Wall-mounted white water heater with exposed copper pipes in a narrow utility closet
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Knoxville's only tankless‑only company

We don't do general plumbing — only tankless.

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Licensed Contractor & Plumber

TN License CMC-A/BC-A #81430.

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Upfront Pricing

Accurate replacement costs with no surprises.

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Fast Turnaround

Most replacements completed same day.

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Code‑Compliant Installations

Venting, gas sizing, condensate, clearances, electrical — all done right.

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Clean Workmanship

Neat, architectural installs that look as good as they perform.

Know When It's Time

Signs Your Tankless Needs Replacement

  • System won’t ignite or repeatedly shuts down
  • Lukewarm water or temperature swings
  • Persistent error codes
  • Leaking heat exchanger
  • Unit is 12–18+ years old
  • If repair cost approaches 40–50% of replacement


If your tankless is failing, we’ll diagnose it accurately and honestly — if replacement is the best option we'll explain why and walk you through the best options to fit your needs.

Technician inspecting plumbing inside a red water heater, wearing gloves and leaning in to adjust parts

We inspect your existing unit, venting, gas line, water lines, and electrical for issues.

System Evaluation

We perform system diagnostics to determine if replacement is needed and or recommended.

Perform diagnost evaluation

We match your home’s demand with the correct tankless system — no oversizing or undersizing.

Model Selection

  • We review with client all the benifits and features of the new tankless and what to expect.
  • We either install your new tankless heater immediately or on a day that's most convenient for you.
  • We take care of the permiting and inspection process with the local authority.

Review Recommended Replacement Features & Cost

Installed to manufacturer specs and local code, including:

  • Code compliant installation.
  • Proper intake and exhaust venting.
  • Gas line sizing & installation, plus sediment trap.
  • Hot & cold isolation ball valves.
  • Expansion tank.
  • Isolation service valves with flush ports.
  • Any electrical requirements.
  • Installation of recirculation and comfort valve to deliver
  • Constant hot water too all fixtures in your home (recommended with most heaters).

Professional Installation

We dial in flow rates, temperature, and recirculation settings.

System Startup & Calibration

We register your new tankless system for full manufacturer warranty coverage.

Warranty Registration

Simple Replacement Process

Our Tankless Replacement Process

From your initial inspection to the final installation, our experienced team follows a proven process to ensure a smooth, efficient, and code-compliant tankless water heater replacement.

TANKLESS REPAIR ❏ WATER HEATER REPLACEMENT ❏ TANKLESS INSTALLATION ❏ TROUBLESHOOTING ERROR & CODES ❏ TANKLESS REPLACEMENT ❏ TANKLESS REPAIR ❏ WATER HEATER REPLACEMENT ❏ TANKLESS INSTALLATION ❏ TROUBLESHOOTING ERROR & CODES ❒ TANKLESS REPLACEMENT ❏
Silver Rinnai wall-mounted water heater with a small black control panel and top vents
Technician inspecting wiring inside an open wall-mounted HVAC unit

All Major Manufacturers

Brands We Replace

If it’s tankless, we can replace it! Common systems include:

  • Navien: NPE‑A2, NPE‑S2, NPN series.
  • Rinnai: RU, RUR, RL, V series.
  • Noritz: NRC, NR, EZ series.
  • Rheem: Prestige, Professional series.
  • Bosch, Takagi, AO Smith, State, and more.
Navien
Rinnai
Noritz
Rheem
Bosch
Takagi
AO Smith
State

Rockwood

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Areas We Serve

Knoxville

Farragut

Hardin Valley

Powell

Karns

Oak Ridge

Lenoir City

Maryville

Making the Right Choice

Replacement Options & Important Considerations

Explore your available replacement options and understand why upgrading at the right time helps protect your home's comfort, efficiency, and long-term reliability.

Tankless Replacement Options

Most replacements recommendations usually are:

  • Standard Tankless Replacement.
  • High‑Efficiency Condensing Replacement.
  • Recirculation Add‑On's.
  • Additional Water Treatment Options Available.

You will always receive a clear, written quote before work begins.

Why Replacing Your Tankless Matters

A failing tankless can cause:

  • Sudden loss of hot water
  • Water damage from leaks
  • Higher gas usage
  • Unsafe combustion or venting issues
  • Repeated shutdowns and error codes

Replacing an end‑of‑life tankless ensures safety, reliability, and long‑term performance.

Ready for a Tankless Replacement?

Call Tankless Heater Pros:

(865) 407-1147