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Tankless Water Heater Installation Cost & Process in Nashville

What does it actually cost? What's involved? How long does it take? Complete cost breakdown and step-by-step process—no surprises, no hidden fees.

NashvilleFranklinBrentwood
Professional tankless water heater installation in Nashville home

Installation Guide

Gas Tankless Installation Cost: Complete Breakdown

The honest answer: $2,500-$6,000 total installed cost in Nashville. Here's exactly what you're paying for:

Equipment
$1,000 - $2,600

Navien NPE-2 series condensing tankless based on size needed

  • 6-7 GPM models (1-2 bathrooms): $1,400-$1,700
  • 8-9 GPM models (2-3 bathrooms): $1,800-$2,300
  • 10-11 GPM models (3-4 bathrooms): $2,200-$2,600
Labor & Installation
$800 - $1,500

Professional installation by licensed plumber

  • Straightforward swap: $800-$1,200
  • Complex installation: $1,200-$1,500
  • Includes mounting, connections, testing
Gas Line Upgrade
$350 - $750

Upsize from 1/2" to 3/4" if needed

  • Short run (under 30 feet): $350-$500
  • Longer run (30-60 feet): $500-$750
  • Not always required—we evaluate
Venting
$100 - $600

PVC intake and exhaust vent pipes

  • Short run (under 20 feet): $100-$250
  • Moderate run (20-50 feet): $250-$400
  • Long run (50-75 feet): $400-$600
Electrical Outlet
$100 - $250

120V outlet for tankless controls

  • Outlet nearby: $100-$150
  • New circuit run: $150-$250
  • Only 2-4 amps required
Permit & Inspection
$50 - $150

Required for code compliance

  • Nashville Metro: $50-$100
  • Franklin/Brentwood: $75-$150
  • We handle everything
Professional tankless water heater installation process

Real-World Nashville Installation Examples

Simple Replacement
1,800 sq ft home

Tankless in same garage location, 3/4" gas line adequate, short vent run

Unit:Navien NPE-180A2 (8 GPM)
Total Cost:$2,800
Moderate Complexity
2,400 sq ft home

Relocated to attic, gas line upsized 1/2" to 3/4" (30 ft), new PVC venting through roof, new outlet

Unit:Navien NPE-240A2 (10 GPM)
Total Cost:$4,200
High Complexity
3,200 sq ft home

Exterior wall install, 50-foot gas line run, gas meter upgraded, outdoor vent kit

Unit:Navien NPE-240A2 (10 GPM)
Total Cost:$5,600

What's Included in Will's Friends Installation

When you choose Will's Friends, here's exactly what we do—no shortcuts, no surprises.

Free In-Home Assessment

We evaluate your fixtures, calculate peak demand, inspect infrastructure, and provide a detailed quote with everything included.

45-90 minutes
Permit Acquisition

We pull permits, pay fees, and ensure code-compliant installation. You don't lift a finger.

We handle it
Old Water Heater Removal

We drain, disconnect, and haul away your old tank water heater. No mess left behind.

1-2 hours
Infrastructure Upgrades

Gas line upsizing, electrical outlet installation, venting prep—all done to code.

2-4 hours
Tankless Installation

Wall mounting, water connections, gas connections, venting, electrical—professional installation.

2-3 hours
Commissioning & Training

Testing, temperature setting, leak checks, performance verification, and owner training.

1 hour
Navien tankless water heater - compact and efficient

Installation Day: Step-by-Step Process

What Happens on Installation Day

MorningPreparation & Removal

  • • Arrive on time (30-minute text heads-up)
  • • Lay drop cloths and floor protection
  • • Shut off water, gas, and power
  • • Drain and disconnect old tank
  • • Remove old tank and venting (haul-away included)

Mid-DayInfrastructure Upgrades

  • • Gas line upsizing if needed (pressure-tested)
  • • Electrical outlet installation if needed
  • • PVC venting installation with proper slope
  • • All work done to code specifications

AfternoonTankless Installation

  • • Mount tankless unit on wall studs
  • • Connect water inlet/outlet with shutoff valves
  • • Connect gas line with shutoff and sediment trap
  • • Connect vent pipes with proper seals
  • • Connect electrical power
  • • Install recirculation if equipped

Late AfternoonCommissioning & Training

  • • Fill system and purge air
  • • Power on and set temperature
  • • Test multiple fixtures simultaneously
  • • Check for leaks (water and gas)
  • • Verify venting draft and condensate drainage
  • • Train you on operation and maintenance
  • • Clean work area completely
Completed tankless water heater installation

Nashville-Area Installation Considerations

Home Age

Pre-1980:

Likely 1/2\" gas lines need upsizing

1980-2010:

Often tankless-ready with minor upgrades

Post-2010:

Usually tankless-ready infrastructure

Water Quality

Nashville: ~100.5 mg/L hardness

  • • Annual descaling required
  • • Sediment filter recommended
  • • Water softener optional but beneficial
Groundwater Temp

55-60°F year-round average

  • • 62-65°F temperature rise needed
  • • Better than northern states
  • • Smaller units work efficiently
20-Year Cost Comparison

Gas Tankless

Install:$4,200
Energy:$4,800
Maint:$4,000
20-Year:$13,000

Tank Heater

Install:$1,800
Energy:$7,200
Replace:$4,700
20-Year:$13,700

Electric Tankless

Install:$5,000
Energy:$9,600
Replace:$3,500
20-Year:$18,100
Why Choose Will's Friends for Tankless Installation
  • Navien specialists (15-year warranty)
  • Licensed & insured (TN #4997)
  • Hundreds of Nashville installations
  • Code-compliant, permitted work
  • Free in-home assessments
  • Transparent pricing, no surprises
  • Same-day emergency service
  • Post-installation support
  • Professional tankless installation by Will's Friends

    Installation Cost: Your Questions Answered

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