National tankless water heater installation costs in 2025 typically range from $1,800 to $5,500 for whole-house systems, with gas units averaging $2,700 to $5,500 and electric units averaging $1,800 to $4,200. Total costs depend on fuel type, flow-rate capacity (measured in gallons per minute, GPM), the adequacy of existing infrastructure, and regional labor rates.

What You’ll Learn in this Report

  • National Average Installation Cost: Total installed costs by fuel type and system size
  • Cost by Flow Rate Capacity: Pricing across GPM ratings for point-of-use and whole-house applications
  • Cost by Fuel Type: Gas versus electric tankless water heater installation comparisons
  • Labor and Equipment Breakdown: Typical cost splits between equipment and installation work

 

National Average Installation Cost

Installed totals include equipment, labor, standard venting or electrical connections, permit fees where required, and removal of existing equipment when applicable. Ranges reflect data from U.S. Energy Information Administration equipment cost studies and industry installation surveys.

Tankless Water Heater Configuration Typical Installed Cost Range
Gas tankless (whole-house) $2,700 to $5,500
Electric tankless (whole-house) $1,800 to $4,200
Gas tankless (point-of-use) $800 to $1,500
Electric tankless (point-of-use) $300 to $800
High-efficiency condensing gas $3,200 to $6,000

Interpretation note: Lower ranges reflect straightforward installations with adequate existing gas line or electrical capacity. Upper ranges account for gas line upsizing, electrical panel upgrades, complex venting requirements, or premium high-efficiency condensing models.

Cost by Flow Rate Capacity

Tankless water heater capacity measures in gallons per minute (GPM). ENERGY STAR guidance indicates typical fixture demands: showers use 2.5 GPM, clothes washers use 3.3 GPM, bathroom sinks use 2.2 GPM, and dishwashers use 1.3 GPM. Sizing requires accounting for simultaneous fixture use.

Flow Rate (GPM) Gas Tankless (Installed) Electric Tankless (Installed) Typical Application
2 to 3 GPM $800 to $1,500 $300 to $800 Single fixture point-of-use (sink or shower)
5 to 7 GPM $2,700 to $4,000 $1,800 to $2,800 One to two simultaneous fixtures
8 to 10 GPM $3,500 to $5,500 $2,500 to $4,200 Whole-house with two to three bathrooms
11+ GPM $4,500 to $6,500 Not typically available Large homes with high simultaneous demand

Practical note: Cold climate installations require higher GPM ratings to achieve the desired temperature rise. Incoming water temperature affects unit capacity. Undersized units cannot maintain temperature during peak demand periods.

Cost by Fuel Type

Gas and electric tankless systems carry different installation requirements based on infrastructure needs.

Fuel Type Equipment Cost Range Installation Labor Range Total Typical Range Key Installation Requirements
Natural gas $1,200 to $3,500 $1,500 to $2,000 $2,700 to $5,500 Gas line capacity verification and potential upsizing, specialized venting systems, combustion air supply
Propane $1,200 to $3,500 $1,500 to $2,000 $2,700 to $5,500 Similar to natural gas, with additional fuel storage considerations
Electric $800 to $2,000 $1,000 to $2,200 $1,800 to $4,200 High-amperage dedicated circuits, potential electrical panel upgrades

Installation complexity note: Bureau of Labor Statistics data indicates median plumber wages of approximately $30 per hour. Installed labor costs reflect additional factors, including contractor overhead, regional market rates, and project complexity.

Labor and Equipment Breakdown

Installation labor accounts for 40% to 55% of the total cost of standard tankless water heater installations. Complex projects requiring significant infrastructure upgrades tend to have higher labor percentages.

Installation Component Typical Cost Range Time Required
Standard electric tankless installation (adequate electrical capacity) $1,000 to $1,500 3 to 5 hours
Standard gas tankless installation (adequate gas line) $1,500 to $2,000 4 to 6 hours
Gas line upsizing (half-inch to three-quarter-inch) $500 to $1,500 3 to 6 hours
Electrical panel upgrade and circuit addition $1,000 to $2,500 4 to 8 hours
Venting system installation or modification $400 to $1,200 2 to 4 hours
Permit acquisition and inspection $50 to $300 1 to 2 days (scheduling)

Regional variation context: Labor rates vary by market. Metropolitan areas typically trend above national median rates. Rural markets commonly fall below national averages.

 

Installation Complexity Factors

Multiple variables influence the final cost of installing a tankless water heater beyond base equipment and standard labor.

🔧 Gas Line Capacity and Sizing
Tankless units require higher BTU input than tank water heaters. Existing gas lines frequently require upsizing. Half-inch gas lines serving tank water heaters typically need replacement with three-quarter-inch lines for tankless applications. The distance from the gas meter to the installation location affects material costs.
⚡ Electrical Service Requirements
Whole-house electric tankless units demand 100 to 150 amps. Homes with 100-amp or 150-amp electrical panels often require service upgrades for adequate capacity. Dedicated high-amperage circuits require proper wire gauge and breaker sizing.
🌬️ Venting Modifications
Gas tankless units require Category III or Category IV venting systems. Existing vent systems for tank water heaters typically require complete replacement. Venting material costs vary by length, number of directional changes, and termination requirements.
📍 Installation Location Accessibility
Attic installations, crawlspace locations, and areas with limited clearance increase labor hours. Outdoor installations eliminate indoor venting requirements but may require freeze protection in cold climates.
📋 Code Compliance and Permits
Local codes specify minimum vent clearances, combustion air requirements, and, where applicable, seismic restraints. Permit requirements vary by jurisdiction.

 

Tankless vs Tank Water Heater Cost Comparison

Upfront installation costs for tankless and traditional tank technologies.

Water Heater Type Typical Installed Cost Expected Lifespan Efficiency Range
Tank (electric) $900 to $2,000 8 to 12 years Energy Factor 0.90 to 0.95
Tank (gas) $1,200 to $2,500 8 to 12 years Energy Factor 0.60 to 0.70
Tankless (electric) $1,800 to $4,200 15 to 20 years Uniform Energy Factor 0.96 to 0.99
Tankless (gas) $2,700 to $5,500 15 to 20 years Uniform Energy Factor 0.82 to 0.96

Cost context: U.S. Department of Energy data indicates tankless water heaters last 20 or more years compared to 10 to 15 years for tank models. Tankless units provide 8% to 34% greater energy efficiency, depending on household hot water consumption patterns.

 

Methodology

Cost ranges compile and normalize data from U.S. Energy Information Administration equipment cost studies (Appendix B residential equipment costs), Bureau of Labor Statistics wage data for plumbing trades, Department of Energy efficiency and lifespan research, ENERGY STAR sizing guidance, and industry installation surveys from Air-Conditioning, Heating & Refrigeration Institute shipment tracking and Northwest Energy Efficiency Alliance installation practice studies. Ranges reflect regional labor rate variation, urban versus rural market differences, installation-complexity tiers, and equipment-efficiency levels. Installed totals assume residential replacement with code-compliant venting or electrical connections, standard permit fees, and removal of existing equipment. Complex installations involving extensive infrastructure modifications may exceed these ranges. Data compiled November 2025.

 

Sources

U.S. Department of Energy: Tankless or Demand-Type Water Heaters – Efficiency data, lifespan comparisons, technology overview

U.S. Energy Information Administration: Residential Equipment Costs Appendix B – Equipment and installed cost data, efficiency ranges, lifespan data

ENERGY STAR: Whole Home Tankless Gas Water Heaters – Sizing guidance, GPM requirements by fixture, efficiency standards

Bureau of Labor Statistics: Plumbers, Pipefitters, and Steamfitters – Wage data for labor cost context

Air-Conditioning, Heating & Refrigeration Institute: Monthly Shipments – Market data and industry trends

Northwest Energy Efficiency Alliance: Gas Tankless Water Heater Research – Installation practices and market analysis

Consumer Reports: Water Heater Buying Guide – Equipment pricing benchmarks and testing methodology

 

Notes

Bands are national planning ranges. Local quotes vary with equipment tier, fuel type, installation accessibility, existing infrastructure, permit scope, and regional labor rates.

Gas tankless units often require gas line upsizing from half-inch to three-quarter-inch, adding $500 to $1,500, depending on distance and complexity.

Electric tankless units demand 100 to 150 amps. Homes with 100-amp service frequently need 200-amp panel upgrade,s adding $1,000 to $2,500.

Cold climate installations require higher GPM ratings. Incoming water temperature affects the achievable temperature rise. Northern regions need higher capacity than southern regions to maintain adequate flow.

Proper sizing requires analysis of simultaneous fixture use patterns. Undersized units cannot maintain the desired water temperature during peak usage.

Request itemized estimates separating equipment cost, labor hours and rate, infrastructure work, venting materials, permit fees, and removal charges to enable accurate contractor comparison.