About tankless water heater costs
The ranges below reflect typical installed costs across the US. What you actually pay depends on the unit you choose, the contractor you hire, and whatever infrastructure your home needs. Gas-to-gas replacements on existing setups land near the low end; full conversions with new venting and gas-line work land near the top. Enter your details in the calculator above for a closer estimate, then verify with written quotes from licensed plumbers.
Average tankless water heater cost
| Scenario | Installed cost range |
| Electric tankless (installed) | $800 - $2,500 |
| Gas tankless (installed) | $2,000 - $4,500 |
| Unit only | $500 - $1,500 |
| Gas line / venting upgrade | $300 - $1,500 |
| Point-of-use unit | $200 - $800 |
A worked example from the calculator above
Take a household in the Denver metro (ZIP 802xx, an average-cost market at roughly 0.92 on the tool's local multiplier) replacing one whole-house gas unit with a standard install. The calculator's base range is $1,800 to $3,000 for a whole-house gas unit at a standard install. Multiply both ends by the fuel factor (1 for gas), the coverage factor (1 for whole house), the install factor (1 for standard), and the 0.92 area adjustment, and the tool lands on roughly $1,660 to $2,760 installed. Switch the install complexity to "gas line / venting upgrade" and the same household's range climbs to about $2,320 to $3,860, because that option carries a 1.4 multiplier in the underlying model. That is the whole mechanism: a base range times whichever factors match your fuel, coverage, install complexity, ZIP, and unit count.
Common costly mistakes
- Comparing a bare unit price to an installed quote. The unit is often a third or less of the total once labor, venting, and any gas-line or panel work are added in.
- Assuming an electric swap is automatically cheaper. A high-kW electric unit that needs a panel upgrade can cost as much installed as a straightforward gas replacement.
- Skipping the venting question. Gas tankless units use different venting than a tank heater's B-vent flue, and finding that out mid-install adds cost and time nobody budgeted for.
- Taking a phone estimate as final. The number on this page and the one your contractor gives over the phone are both starting points. The one that matters is the itemized written quote after they have seen your gas line, electrical panel, and unit location.
- Undersizing for peak demand. A unit sized for one shower can leave a household of four running out of hot water when someone starts the dishwasher at the same time.
How to read your result
The number the calculator shows is a range, not a quote, and that is on purpose. The low end assumes your existing gas line, venting, or electrical service already supports a tankless unit. The high end assumes some of that infrastructure needs work. Your ZIP adjustment shifts both ends together based on typical plumber labor rates in that market, it does not widen or narrow the spread. If a contractor's bid lands above the high end, ask specifically what infrastructure work is driving it before assuming you are being overcharged.
What affects tankless water heater cost
- Fuel type: gas units need venting and often a larger gas line; electric units need adequate amperage and sometimes a panel upgrade.
- Sizing: higher-GPM and whole-house models cost more than a single-fixture point-of-use unit, which can run as low as $200 installed.
- Infrastructure work: new venting, gas-line extensions, or panel upgrades can add $300 to $2,000 to the project.
- Condensing vs. non-condensing: condensing gas units run more efficiently but cost more upfront.
- Labor: licensed plumbers charge more than unlicensed ones, but their work passes inspection.
- Location: permit fees and labor rates differ noticeably across US markets.
Before you decide: common questions
How much does a tankless water heater cost?
Installed, gas units run $2,000 to $4,500 and electric units $800 to $2,500. Those ranges cover the unit plus labor, but not infrastructure upgrades like new venting or panel work, which can add $500 to $2,000 more.
Is a tankless water heater worth it?
For most homeowners planning to stay 10 or more years, yes. Tankless units last about 20 years, roughly twice a tank heater, and cut annual water-heating costs by $100 to $150. That math improves when you factor in the replacement cycle you avoid.
Do I need to upgrade my gas or electrical?
Often yes. Gas tankless units draw 150,000 to 200,000 BTU at peak, more than most existing gas lines are sized for. Electric whole-house models typically need a dedicated 40-to-60-amp circuit and frequently trigger a panel upgrade from 100 to 200 amps.
How much can a tankless heater save?
The U.S. Department of Energy estimates 10 to 30 percent on water heating costs versus a standard storage tank. Higher-use households and those with higher utility rates tend to see savings toward the top of that range.
Tankless vs tank: which is better?
It depends on the timeline. Tankless wins on long-term operating cost, lifespan, and continuous hot water. Tank wins on upfront price and installation simplicity. For anyone staying more than 8 to 10 years, total cost of ownership tends to favor tankless.
How much does it cost to install a tankless water heater?
Gas model installation typically runs $1,000 to $3,500 all in. Electric models can be cheaper to buy but often require a panel upgrade that closes the gap. The job costs more when new gas lines, venting, or significant electrical work is needed, which is why itemized quotes from licensed plumbers matter more than ballpark figures.
What is the downside of a tankless water heater?
Higher upfront cost and more complex installation are the main ones. There is also the "cold water sandwich" effect, a brief burst of cooled water that can arrive between hot draws while the heat exchanger re-fires. Gas units need proper venting. Large households may need a higher-GPM unit to avoid hot water shortfalls when multiple fixtures run at once. Annual descaling is required in hard-water areas.
Can I replace my 40 gallon water heater with a tankless water heater?
Yes, but it is not a straight swap. Gas tankless units need dedicated venting and potentially a larger gas line. Electric models may need a panel upgrade. A licensed plumber can assess your existing setup and quote the full conversion cost. Budget $1,200 to $3,000 for most 40-gallon-to-gas-tankless conversions.
How much does a tankless water heater cost for a 2000 square foot home?
A 2,000-square-foot home typically needs a unit rated at 7 to 10 GPM. A gas unit in that range costs $700 to $1,200, plus $400 to $1,200 in labor and venting, putting the total at roughly $1,500 to $3,200 installed. If your existing gas service and location are in good shape, expect the lower end of that range.
In-depth tankless water heater guides
Talk to a pro before you commit
Your actual cost depends on fuel type, unit capacity, and whatever infrastructure your home needs. The calculator gives you a starting point. A few itemized quotes from licensed local plumbers give you the real number.
Talk to a licensed plumber before you buy
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