A tankless water heater typically costs $1,000-$5,500 installed, with an average near $2,800 for a standard residential replacement. The final price depends on fuel type, unit capacity, venting, electrical or gas-line work, and whether an existing tank must be removed.
| Item | Low | Average | High | Notes |
|---|---|---|---|---|
| Installed electric unit | $900 | $2,000 | $4,000 | Often needs a dedicated high-amperage circuit |
| Installed gas unit | $1,500 | $3,200 | $5,500 | May require new venting or a larger gas line |
| Tankless unit only | $400 | $1,200 | $2,500 | Price varies by capacity and efficiency |
| Labor and common conversion work | $500 | $1,300 | $3,000 | More for difficult access or system upgrades |
What a standard tankless water heater installation costs
For a typical 2- to 3-bathroom home, a midrange gas unit with standard installation commonly totals $2,000-$4,000. A smaller electric model installed where wiring is already adequate may cost $900-$2,500. Premium condensing gas systems, substantial utility upgrades, or remote installation locations can push the total above $5,000.
Equipment alone often runs $400-$1,500 for common residential models; high-capacity or premium units may reach $2,500. A realistic budget for a straightforward gas replacement is about $2,800, before unusual code or utility work.
Assumptions: U.S. residential installation, standard-quality equipment, normal access, and no major plumbing or utility upgrade.
How equipment, labor, and venting shape the quote
Quotes divide into the heater, installation labor, and conversion work. Existing tank-to-tankless projects can require new venting, gas piping, electrical service, condensate drainage, or plumbing adjustments. Ask whether removal, disposal, permit fees, and startup testing are included.
| Quote component | Typical price | What changes the charge |
|---|---|---|
| Tankless unit | $400-$2,500 | Fuel, capacity, brand tier, and condensing design |
| Installation labor | $500-$1,800 | Access, conversion complexity, and crew time |
| Venting and fittings | $150-$900 | Vent material, route length, and wall or roof work |
| Gas or electrical upgrade | $300-$2,000 | Line size, circuit capacity, and distance to equipment |
| Removal, permit, and disposal | $100-$600 | Local permit rules and old tank handling |
Conversion work—not just the heater’s sticker price—often creates the largest difference between two installation quotes.
How flow rate and incoming water temperature change sizing
Tankless units are rated by flow, measured in gallons per minute (GPM), and temperature rise. A unit delivering 5 GPM may suit a smaller household with limited simultaneous hot-water use; a larger home may need 8-10 GPM or multiple units. Undersizing can mean reduced flow when showers and appliances run together.
Climate matters because colder incoming water requires a greater temperature rise. A unit that supplies 8 GPM in a warm region may provide materially less flow in a cold-winter area. Gas models commonly cost more to install than basic electric models, but can serve higher whole-home demand.
Confirm the required GPM at the local winter inlet-water temperature before comparing model prices.
Why gas-line size and electrical capacity add to the total
Many gas tankless heaters require a larger gas supply than a conventional tank. If an existing line is undersized or runs more than 20-30 feet to the unit, a contractor may need to replace or extend it, adding roughly $300-$1,500. Longer runs and difficult routing can cost more.
Whole-home electric units may require multiple 240-volt circuits and substantial panel capacity. A new circuit or wiring can add $300-$1,500; panel upgrades may add $1,000-$3,000 or more. Labor varies by job: a straightforward installation may take 4-8 hours, while a conversion can take 1-2 days.
Ask the installer to inspect the gas meter, line size, panel, and vent route before issuing a fixed quote.
Gas versus electric tankless units for whole-home use
Electric units generally have a lower equipment price, often $400-$1,200 for common models, but whole-home installation can become expensive when the panel or wiring needs upgrades. Gas units often cost $700-$2,000 for standard equipment and may need more costly venting and fuel-line work. Exact prices depend on capacity and local labor.
Point-of-use electric models can cost $150-$500 and may work for a single sink or remote fixture, but they are not a like-for-like substitute for a whole-home system. Compare installed totals and expected simultaneous demand rather than choosing by appliance price alone.
For a whole-home comparison, include utility upgrades and required flow capacity in both estimates.
Regional labor rates and permit charges to check
Installed prices in high-cost metro areas, including parts of the Northeast and West Coast, may run 10%-25% above the national midpoint. Smaller cities and rural markets can be 5%-15% lower, although limited contractor availability or longer travel distances can erase the savings. These are broad comparisons, not guaranteed local rates.
Permit and inspection charges commonly range from $50-$300, with higher fees possible where multiple trades or code corrections apply. Gas venting, combustion air, seismic strapping, and condensate disposal requirements vary by jurisdiction. Check local permit costs and code requirements before treating a low online price as an installed quote.
Removal, venting, and other charges that can appear
Removing and hauling away an old tank often adds $100-$300. A new vent route or wall penetration may add $200-$900, while condensate pumps or drains for condensing models may add $100-$500. Diagnostic or estimate visits can cost $75-$200, though some contractors waive the fee when hired.
Warranty terms differ by manufacturer and model; some warranties require professional installation and routine flushing. In hard-water areas, a scale filter or periodic descaling may be recommended, adding equipment or maintenance expense. Have each quote identify exclusions, warranty coverage, and required accessories separately.
Ways to lower the tankless installation price
Keep the unit near existing plumbing, gas, and vent locations when code permits. Reusing a suitable vent or utility connection can avoid costly rerouting, but only if the manufacturer and local rules allow it. Choose capacity based on measured peak demand instead of automatically buying the largest model.
Compare at least three itemized quotes for the same fuel type and GPM requirement. Schedule work outside peak replacement emergencies when possible, and ask whether a standard-efficiency model meets the household’s needs. Avoid paying for a panel upgrade, water treatment system, or premium controls without confirming the need.
The strongest savings usually come from reducing conversion work while preserving correct sizing and code-compliant installation.