Tankless Water Heater Cost: Unit, Install, and the Tank-vs-Tankless Math
A tankless water heater typically costs $1,600 to $3,800 installed for a whole-home unit, per SolarReviews, and The Home Depot lists professional installation at $2,400 to $5,400. The spread is wide because a simple electric swap and a full gas retrofit are two different jobs. Below are the unit and install numbers by type, the tank-vs-tankless payback math, and the hidden conversion costs that catch people off guard.
What a tankless water heater costs: unit plus install
Budget $1,600 to $3,800 for a whole-home tankless water heater installed, with the equipment running $500 to $3,200 and labor adding $500 to $2,000 depending on fuel type and retrofit work. Electric point-of-use units for a single fixture start around $400. Gas units cost more than electric, and condensing gas models cost the most because they wring extra efficiency out of the exhaust.
| Type | Unit only | Install labor | Typical installed total |
|---|---|---|---|
| Point-of-use electric (single fixture) | $150 to $400 | $100 to $350 | $400 to $750 |
| Whole-home electric | $500 to $1,500 | $500 to $1,000 | $1,000 to $2,500 |
| Whole-home gas (non-condensing) | $1,000 to $2,800 | $1,000 to $2,500 | $2,400 to $4,500 |
| Whole-home gas (condensing, high-efficiency) | $1,500 to $3,200 | $1,200 to $2,500 | $3,000 to $5,400 |
Unit-cost ranges by fuel type are from CR Plumbing (2026); installed totals blend SolarReviews and The Home Depot figures. Labor tracks your local plumber’s shop rate, so see what plumbers charge per hour to sanity-check a bid. Costs vary by region and by how much retrofit work your home needs.
Gas vs electric tankless: which costs more to buy and run
Gas tankless units cost more upfront and to install but heat water for less per year in most homes, while electric tankless units are cheaper to buy and simpler to install but can force a costly electrical panel upgrade. Gas suits whole-home demand in cold climates; electric works well for smaller homes, warm inlet water, or point-of-use jobs.
Consumer Reports measured annual operating cost at roughly $195 for a gas tankless versus $535 for an electric tankless, a gap driven by electricity prices. A whole-home electric tankless can pull 120 to 150 amps, which often means upgrading the service panel to 200 amps. That upgrade may run $1,300 to $3,000 in many areas, so the “cheaper” electric unit sometimes ends up costing more to install than gas.
The real retrofit cost: switching a tank to tankless
Converting from a storage tank to a tankless unit adds line items a like-for-like swap never touches: a larger gas line, new venting, a condensate drain, and possibly an electrical upgrade. These adders are the single biggest reason quotes jump from $2,400 to $5,000-plus. The Home Depot notes that adding a gas line alone can raise a job by $3,000 or more.
Here is the conversion “cost stack” most competitor guides bury in a paragraph. Attach whichever lines apply to your home on top of the base unit-plus-labor price.
| Retrofit line item | Why it is needed | Typical added cost |
|---|---|---|
| Gas line upsizing (to 3/4 in.) | A gas tankless fires at 150,000 to 199,000 BTU, far above a tank | $500 to $2,000+ |
| New venting (stainless or PVC) | Tankless exhaust differs from a tank flue; condensing units need PVC | $300 to $800 |
| Condensate drain (condensing models) | High-efficiency units produce acidic condensate that must drain | $150 to $500 |
| Electrical panel upgrade (electric units) | Whole-home electric can need 200-amp service | $1,300 to $3,000 |
| Permit and inspection | Required for gas, venting, and electrical work in most jurisdictions | $100 to $300 |
Line-item ranges are from CR Plumbing (2026) and The Home Depot. Your local code sets what is required, so check the venting and permit rules before you commit. In many areas a permit is not optional for gas or venting changes.
Tank vs tankless: the full comparison
Tankless costs more upfront but lasts about twice as long, saves modestly on energy, and never runs out of hot water. A tank costs less to buy and install and is the simpler replacement, but it wears out sooner and reheats a fixed supply. The right choice depends on how long you will stay and whether endless hot water is worth the premium.
| Factor | Storage tank | Tankless |
|---|---|---|
| Installed cost (like-for-like) | $1,200 to $2,500 | $1,600 to $3,800 (more for a retrofit) |
| Annual operating cost (gas) | ~$245 | ~$195 |
| Annual operating cost (electric) | ~$580 | ~$535 |
| Efficiency vs tank (DOE) | Baseline | 24% to 34% better under 41 gal/day; 8% to 14% for heavy users |
| Lifespan | ~10 to 12 years | ~20 years |
| Hot water supply | Fixed tank; can run out | Endless at rated GPM |
| Cold-water sandwich | No | Yes, unless buffered or recirculated |
| Footprint | Floor-standing, 30 to 60 gal | Wall-mounted, small |
Operating-cost and efficiency figures are from Consumer Reports and the U.S. Department of Energy. This page focuses on the tankless decision; for tank sizing, repair-vs-replace, and standard 40 to 50 gallon pricing, see our full water heater replacement cost guide.
Endless hot water, with a catch
Tankless delivers continuous hot water but only up to its flow rating, so a unit rated at 4 to 5 gallons per minute may not run two showers and a dishwasher at once. Consumer Reports found tankless models hit their target 3 to 4 GPM in testing, yet noted you might not run the washing machine while someone showers. Size the unit to your peak simultaneous demand, not your total daily use.
The cold-water sandwich
The cold-water sandwich is the brief slug of cold water between two hot draws, and it is the most common tankless complaint. Hot water sitting in the pipe reaches you first, then cold arrives before the burner ramps back up. A recirculation loop, a small buffer tank, or a model with a built-in buffer smooths it out. Budget extra if uninterrupted hot water matters to you.
Payback: when tankless actually saves money
Payback on a tankless conversion runs 12 to 27 years for most households, but drops to 5 to 10 years for low-use homes, per Consumer Reports and the DOE. Because the energy savings are modest and the retrofit premium is real, many owners never reach break-even before they sell. The honest case for tankless is often the perks (endless hot water, space, longer life), not the utility bill.
- Estimate your annual saving: roughly $50 a year for gas or $45 for electric versus a same-fuel tank, per Consumer Reports. Low-use gas homes may save $100 or more.
- Total your installed cost premium: subtract a comparable tank install ($1,200 to $2,500) from your tankless quote, including any retrofit adders.
- Divide the premium by the annual saving for a rough payback in years. A $2,000 premium at $100 a year saved is a 20-year payback.
- Subtract incentives first: the federal 25C credit covers 30% up to $600 on a qualifying gas unit, and utility rebates can add $100 to $1,200.
Efficiency rules are tightening too, which affects both what you can buy and what it costs. See the 2026 water heater efficiency standards before you shop, since the heat-pump push is reshaping the market. Tax-credit and rebate amounts vary by state and utility, so confirm your unit and program qualify.
Who should choose tankless
Tankless makes the most sense if you plan to stay 15-plus years, want endless hot water, are tight on space, or are already opening up the wall for a remodel. It makes less sense if you are moving soon, your gas line and venting need major work, or a standard tank already meets your demand. Match the unit to your household’s peak flow and your timeline, not to the headline efficiency number.
Frequently asked questions
How much does a tankless water heater cost installed?
Most homeowners pay $1,600 to $3,800 for a whole-home tankless water heater installed, per SolarReviews. The Home Depot puts professional installation at $2,400 to $5,400. A straight electric swap sits at the low end. A gas retrofit that needs a bigger gas line and new venting pushes the total toward $5,000 or more.
Is a tankless water heater cheaper to run than a tank?
Usually, yes. Consumer Reports measured a gas tankless at about $195 a year versus $245 for a gas tank, and an electric tankless at $535 versus $580 for an electric tank. The DOE puts tankless at 24% to 34% more efficient for homes using 41 gallons or less per day, and 8% to 14% for heavier users.
What is the payback period on a tankless water heater?
It depends on your fuel and use. Consumer Reports estimates 22 to 27 years for a gas tank-to-tankless conversion and 12 to 20 years for electric. Low-use households (under 41 gallons a day) can hit payback in 5 to 10 years. Many owners replace before breaking even, so factor in the non-cash perks too.
Why does switching from a tank to tankless cost so much more?
The unit is only part of it. A gas tankless often needs a larger gas line, new stainless or PVC venting, a condensate drain, and sometimes a 200-amp electrical upgrade for electric models. The Home Depot notes adding a gas line alone can add $3,000 or more, which is why a retrofit costs far more than a like-for-like tank swap.
What is the cold-water sandwich?
It is the short burst of cold water you feel between two hot draws on a tankless unit. Hot water already in the pipe reaches you first, then a slug of cold arrives before the burner catches up. A recirculation loop or a small buffer tank on the unit reduces it, and some newer models have a built-in buffer to smooth it out.
Do tankless water heaters qualify for a tax credit?
Many do. The federal Energy Efficiency Home Improvement Credit (25C) covers 30% of the cost of a qualifying high-efficiency unit, capped at $600 for a gas tankless. Utility and state rebates often add $100 to $1,200 on top, depending on your area. Confirm the specific model qualifies before you buy.
Last reviewed: August 2026.