Last updated: October 2026
Most US homeowners pay $1,400 to $3,900 to have a whole-house tankless water heater installed, with national averages clustering around $2,500 to $2,800. A small electric point-of-use unit can cost a few hundred dollars, while converting a gas tank to a large gas tankless unit, with a new gas line, new venting and a condensate drain, can run $4,500 to $6,000 or more.
The single biggest swing factor is not the heater itself. It is what your home needs to support it: a bigger gas line, a new vent through the wall or roof, or an electrical service that can handle 100+ amps for an electric whole-house model. Below we break down every cost line so you can read a plumber’s quote with confidence.
Find out what tankless costs in your home
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Get free quotesTankless water heater cost at a glance
| Item | Typical cost (2026) |
|---|---|
| National average, installed | $2,500 – $2,800 |
| Typical installed range | $1,400 – $3,900 |
| Electric tankless, installed | $650 – $3,000 |
| Gas (natural gas or propane) tankless, installed | $1,400 – $3,500 |
| Unit only, whole-house | $450 – $2,000+ |
| Unit only, point-of-use (single sink/shower) | $100 – $500 |
| Installation labor | $500 – $1,850 |
| Tank-to-tankless conversion extras (gas line, venting, electrical) | $400 – $3,000+ |
| Annual maintenance (descaling/flush) | $100 – $350 per visit |
These ranges are compiled from Angi (national average $2,641, typical range $1,406–$3,902, updated August 2026), HomeAdvisor (average $2,547, range $1,393–$3,814), This Old House (average $2,800, range $1,200–$3,500, updated June 2026) and Fixr (average about $2,811). Where sources differ, we show the overlap that most homeowners fall into.
How much does a tankless water heater cost by fuel type?
The fuel you use determines both the price of the unit and the work needed to install it. Gas units cost more to buy and install, but they usually cost less to run and can supply more hot water at once.
| Fuel type | Unit cost | Labor | Total installed |
|---|---|---|---|
| Electric | $450 – $1,500 | $150 – $1,000 | $650 – $3,000 |
| Natural gas | $500 – $2,000 | $900 – $1,500 | $1,400 – $3,500 |
| Propane | $500 – $2,000 | $900 – $1,500 | $1,400 – $3,500 |
Sources: This Old House and Fixr fuel-type breakdowns. Totals assume a straightforward replacement; conversion work is extra (see below).
Electric tankless water heater cost
Electric tankless water heaters are the cheapest to buy and the simplest to plumb because they need no gas line and no vent. A whole-house electric unit typically costs $450 to $1,500, and installed prices commonly fall between $650 and $3,000. The catch is power. A 27 kW whole-house electric model draws well over 100 amps at 240 volts, which usually means two or three dedicated double-pole breakers and heavy-gauge wiring. HomeAdvisor notes that whole-house electric units need at least 240V, 80-amp hard-wired service and that the home should have at least 150-amp service; many electricians prefer 200 amps. If your panel is full or undersized, the electrical work can cost more than the heater.
Electric tankless is also limited by incoming water temperature. In northern states where groundwater may enter the house at 40–50°F, an electric unit has to raise the temperature by 70°F or more, which cuts its flow rate. Electric whole-house models are a better fit in warm-climate states, smaller homes, or as point-of-use units.
Gas tankless water heater cost
Gas tankless units cost $500 to $2,000 for the heater and roughly $1,400 to $3,500 installed for a like-for-like job. Large condensing models rated around 199,000 BTU/h can deliver enough hot water for two showers plus an appliance, even in cold climates. Condensing units run more efficiently and can vent through inexpensive PVC pipe, but they cost more up front (Bob Vila estimates about 25% more than non-condensing models) and need a condensate drain.
Propane tankless units cost about the same as natural gas units. Many models can be converted between fuels, but some require a conversion kit, so confirm which fuel the unit is configured for before you buy.
Tankless water heater cost by size (flow rate)
Tankless units are sized by gallons per minute (GPM) at a given temperature rise, not by gallons of storage. A typical shower uses about 2 GPM, so a home that needs two showers and a dishwasher running at once needs roughly 5–7 GPM of capacity at your local temperature rise.
| Flow rate | Typical use | Electric unit | Gas unit |
|---|---|---|---|
| 2 – 3 GPM | One fixture, small apartment | $200 – $300 | $250 – $600 |
| 3 – 4 GPM | 1 bathroom | $300 – $550 | $400 – $700 |
| 5 – 6 GPM | 1–2 bathrooms | $425 – $600 | $500 – $800 |
| 6 – 7 GPM | 2 bathrooms | $500 – $700 | $700 – $900 |
| 8+ GPM | 3+ bathrooms, cold climates | $600 – $1,500 | $900 – $2,000 |
Unit prices only, from Fixr. Premium brands, condensing technology, built-in recirculation pumps and Wi-Fi controls push prices toward the top of each band.
Not sure what capacity you need? Our guide to what size water heater you need walks through peak-demand math for both tank and tankless systems.
Tankless water heater installation cost: labor
Labor for a tankless installation typically runs $500 to $1,850, compared with roughly $150 to $450 for a simple tank-for-tank swap (HomeAdvisor). Tankless jobs take longer because the plumber usually has to wall-mount the unit, re-pipe the water connections, add isolation (service) valves for future descaling, and often modify gas, venting and electrical.
- Plumber rates: $45 to $200 per hour nationally; Fixr and This Old House put most licensed plumbers between $75 and $150 per hour.
- Time on site: 3 hours for an easy electric replacement up to 6–10 hours for a gas conversion.
- Electrician: $50 to $100 per hour for new circuits or breakers.
- Hard-to-reach locations: attics, crawl spaces and tight closets can add 10% to 15% to labor.
For a deeper look at how plumbers price their time, see our breakdown of water heater installation labor cost.
Cost to convert from a tank to a tankless water heater
If you are replacing an existing tankless unit, most of the infrastructure is already in place and you’ll pay close to the base installed price. Converting from a tank is where costs climb. Here is what can be added:
| Conversion item | Typical cost | When it’s needed |
|---|---|---|
| Gas line upsizing (½” to ¾”) | $400 – $800 | Most gas tankless units need far more gas than a tank |
| New gas line run | Up to $800 – $1,000 | Relocating the heater or long runs from the meter |
| New venting (wall or roof) | $400 – $800 | Almost always; tankless can’t use a tank’s old vent |
| Gas pressure regulator replacement | $250 – $350 | If meter/regulator can’t supply the required BTUs |
| New electrical circuit | $200 – $600 | Gas units need 120V for controls; electric units need 240V circuits |
| Electrical panel upgrade | $1,000 – $2,000+ | Electric whole-house units on 100A service |
| Old tank removal and disposal | $100 – $500 | Unless included in the quote |
| Permits and inspection | $50 – $300 | Required in most jurisdictions |
| Wall repair/painting after re-piping | About $200 | If walls are opened |
Sources: This Old House (gas line upsizing, venting, circuits, panel, removal, permits), Angi (gas line, pressure regulator), Fixr (gas line, wall repair). Fixr estimates a typical gas tank-to-tankless conversion adds about $1,700 including the gas line, and an electric conversion adds $90 to $450 when no panel work is needed.
Why gas line size matters
A typical 40- or 50-gallon gas tank uses about 40,000 BTU/h. A whole-house gas tankless heater can draw up to about 199,000 BTU/h when several taps are open. The ½-inch gas line feeding most tanks often can’t deliver that volume over any real distance, especially if your furnace, range and dryer are also on gas. Your plumber should calculate total connected load and pipe length before quoting. If a quote doesn’t mention gas line sizing on a tank-to-tankless conversion, ask about it.
Venting requirements
Tank water heaters often vent into a shared metal flue or chimney. Tankless units need their own vent. Non-condensing units require stainless steel vent pipe, while condensing units can usually use PVC or polypropylene. Both are typically run through an exterior wall or the roof. Location matters: moving the heater to an exterior wall can cut vent costs, but may lengthen water and gas lines.
Electrical requirements
Even gas tankless units need a 120V outlet for their fan and controls. Electric whole-house models are much more demanding. Expect to need dedicated 240V circuits sized to the unit’s amperage. Ask an electrician to do a load calculation before you buy an electric tankless model, since a $700 heater can trigger a panel or service upgrade.
Converting from a tank? Get an itemized quote
Ask local plumbers to price the gas line, venting and electrical work separately so you can compare like for like.
Get free quotesTankless water heater cost by brand
| Brand | Electric models | Gas models |
|---|---|---|
| Rheem | $170 – $575 | $670 – $1,950 |
| Bosch | $140 – $800 | $1,050 – $2,250 |
| EcoSmart | $425 – $725 | $695 – $1,600 |
| Takagi | Not offered | $490 – $1,225 |
| Noritz | Not offered | $515 – $1,700 |
| Rinnai | Not offered | $900 – $1,995 |
| Navien | Not offered | $1,075 – $1,535 |
| Bradford White | $600 – $800 | $1,000 – $1,500 |
Unit-only price ranges from Fixr. Prices vary by model, capacity and retailer, and change frequently.
Brand matters less than correct sizing and a quality installation. That said, check the heat exchanger warranty (often 10–15 years for residential use on major brands) and whether a local plumber stocks parts for that brand.
Tankless water heater maintenance cost
Tankless water heaters need regular descaling, especially in hard-water areas. Minerals build up on the heat exchanger, reducing efficiency and eventually triggering error codes or failures.
| Maintenance task | Typical cost | Frequency |
|---|---|---|
| Professional descaling/flush | $110 – $350 | Every 12 months (6 months with hard water) |
| Annual system cleaning/inspection | $100 – $200 | Yearly |
| Inlet water filter cleaning | DIY (free) | Every few months |
| Water softener or scale-prevention filter | Varies widely | Optional; recommended in hard-water areas |
Sources: Angi (preventive maintenance $50–$350 per visit, flush $110–$200), This Old House (system cleaning $100–$200, descaling up to $500 in some cases), Fixr (yearly, or every 6 months with hard water or high temperature settings).
Many homeowners descale their own units using a small submersible pump, hoses and white vinegar connected to the isolation valves. If your installer adds isolation valves (and they should), DIY descaling is a manageable job. Our guide on how to flush a water heater covers both tank and tankless units.
Common tankless repair costs
Angi puts the average tankless repair at about $600, with typical line items like a gas valve ($150–$550), heating element on electric units ($200–$300) and vent repairs ($50–$125). See our full water heater repair cost guide for more.
Operating costs and savings: is tankless worth it?
The US Department of Energy estimates that for homes using 41 gallons or less of hot water a day, tankless (demand) water heaters are 24% to 34% more energy efficient than conventional storage tanks. For homes using a lot of hot water (around 86 gallons a day), the advantage drops to 8% to 14%. In dollars, that is modest: Angi cites DOE estimates of roughly $100 a year in savings for gas units and $50 a year for electric.
| System | Estimated annual operating cost |
|---|---|
| Gas tankless | About $192 – $264 |
| Gas tank | About $275 |
| Electric tankless | About $300 – $600 |
| Electric tank | About $440 – $580 |
Sources: This Old House and Fixr. Your actual cost depends on local gas and electricity rates and how much hot water you use.
With an extra $1,000 to $2,500 up front versus a tank, energy savings alone often take a long time to pay back. Tankless makes the most financial sense when:
- You already have a gas line and vent route that need little modification.
- You plan to stay in the home long enough to benefit from the longer lifespan (Fixr cites 20+ years for tankless vs 10–15 for tanks).
- You need endless hot water for a large tub or back-to-back showers.
- You need to free up floor space in a small utility room or closet.
For a full side-by-side comparison, read tankless vs tank water heater. If you want the lowest operating cost on an electric system, compare tankless against a heat pump water heater, which typically uses far less electricity than either electric tankless or a standard electric tank.
Factors that affect tankless water heater cost
- Fuel switch: Going from electric tank to gas tankless (or the reverse) adds the most cost because you need new utility service to the heater.
- Capacity: Larger GPM ratings and cold incoming water require bigger, more expensive units.
- Condensing vs non-condensing: Condensing units cost more but are more efficient and use cheaper vent materials.
- Location: Moving the heater to an exterior wall, garage or attic changes piping, venting and labor.
- Recirculation: Units with a built-in recirculation pump, or adding a separate pump and return line, reduce wait time for hot water but add cost.
- Water quality: Hard water may justify a scale-prevention system and more frequent maintenance.
- Local code: Requirements for permits, sediment traps, gas shutoffs, combustion air and condensate neutralizers vary by city.
- Old unit disposal: Some plumbers include haul-away; others charge separately.
Regional cost differences
National averages hide large local swings. Plumber rates range from about $45 to $200 an hour, and the high end is typical in big metro areas in the Northeast and on the West Coast, where licensing, insurance and overhead costs are higher. Permit fees also vary widely, from under $50 in some towns to several hundred dollars in others.
Climate plays a role too. In colder northern states, incoming water is colder, so you need a higher-capacity unit to deliver the same flow. Outdoor-mounted tankless units are common in warm states like Florida, Texas, Arizona and California, which can reduce venting cost, but cold-climate installations may require freeze protection and pipe insulation (Fixr estimates up to $400 extra for cold-climate venting and insulation). The only reliable way to know your local price is to get several itemized quotes.
How to save on a tankless water heater
- Get at least three itemized quotes. Ask each plumber to break out unit, labor, gas line, venting, electrical and permits.
- Keep the heater near the existing location when possible to limit re-piping.
- Check utility rebates. Some gas utilities offer rebates on high-efficiency condensing units; ENERGY STAR’s Rebate Finder lets you search by ZIP code.
- Don’t oversize. A correctly sized unit costs less and runs efficiently. Ask your plumber to show the GPM and temperature-rise math.
- Time it before failure. Replacing a tank that is 10+ years old before it leaks lets you shop calmly instead of paying emergency rates. See our guide to water heater lifespan.
- Consider a tank if the conversion is expensive. If your quotes include $2,000+ in gas line and venting work, a high-efficiency tank or heat pump unit may be the better value. Compare with our water heater replacement cost guide.
A note on federal tax credits
The federal Energy Efficient Home Improvement Credit (Section 25C), which offered up to $600 for qualifying gas tankless water heaters, was ended by the One Big Beautiful Bill Act for property placed in service after December 31, 2025. A tankless heater installed in 2026 does not qualify for that credit. If your unit was installed and placed in service in 2025, you can still claim it on your 2025 tax return. Check local utility and state programs for any remaining incentives.
DIY vs professional tankless installation
Installing a tankless water heater is not a beginner DIY job, and in most places it legally requires a permit. Gas tankless installations involve sizing and connecting gas lines, venting combustion gases, and in many jurisdictions only a licensed plumber or gas fitter may do that work. Mistakes can cause gas leaks, carbon monoxide exposure or fires.
Electric whole-house tankless units involve high-amperage 240V circuits that should be installed by a licensed electrician. A small point-of-use electric unit under a sink is the one realistic DIY project, provided the circuit already exists and your local code allows it.
Doing it yourself can also void the manufacturer’s warranty, since many brands require professional installation. For a $1,000+ heater with a 10–15 year heat exchanger warranty, that is a real risk. If you’re replacing a leaking water heater in a hurry, a professional also handles permits, inspections and haul-away.
How to hire a plumber for a tankless installation
- Verify licensing and insurance. Check your state’s license lookup and ask for proof of liability insurance.
- Look for tankless experience. Ask how many tankless units they install per year and which brands they’re certified with.
- Request an on-site visit. Good quotes require checking your gas meter, gas line size, vent route and electrical panel.
- Get itemized, written quotes from at least three contractors.
- Confirm who pulls the permit and that the price includes inspection.
Questions to ask before you sign
- What GPM do I need, and what temperature rise did you assume for my area?
- Does my gas line need to be upsized, and is that included?
- Where will the vent terminate, and what material will you use?
- Will you install isolation valves for descaling?
- Is the unit condensing? Where will the condensate drain go?
- Does the price include permits, disposal of the old tank and wall patching?
- What does your labor warranty cover, and for how long?
- Will you register the unit for the manufacturer’s warranty?
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Get free quotesFAQs
How much does a tankless water heater cost installed?
Most homeowners pay $1,400 to $3,900 for a professionally installed whole-house tankless water heater, with national averages around $2,500 to $2,800. Converting from a gas tank, with a new gas line and venting, can push the total to $4,500 to $6,000 or more.
How much does it cost to convert from a tank to a tankless water heater?
On top of the heater and basic labor, conversions commonly add $400 to $800 for gas line upsizing, $400 to $800 for new venting, $200 to $600 for an electrical circuit and $1,000 to $2,000+ if an electric unit requires a panel upgrade. Fixr estimates a typical gas conversion adds about $1,700.
Is a tankless water heater worth the money?
It can be if you have gas service nearby, plan to stay in your home long term, want endless hot water or need to save space. DOE estimates tankless units are 24% to 34% more efficient for homes using 41 gallons or less a day, but the dollar savings (often $50 to $100+ a year) mean payback on the higher up-front cost can take many years.
How long does a tankless water heater last?
With regular descaling, many tankless water heaters last 20 years or more, compared with about 10 to 15 years for a typical tank. Lifespan depends on water hardness, usage and maintenance.
Do tankless water heaters need maintenance?
Yes. They should be descaled about once a year, or every six months with hard water. A professional service typically costs $110 to $350, or you can do it yourself with a pump-and-vinegar kit if isolation valves are installed.
Is electric or gas tankless cheaper?
Electric tankless is cheaper to buy and install ($650 to $3,000 installed) but often costs more to run. Gas tankless costs more up front ($1,400 to $3,500 installed) and usually costs less per year to operate, especially for larger households.
What size tankless water heater do I need?
Add up the flow rates of fixtures you’ll run at the same time (a shower is about 2 GPM) and size for the temperature rise in your area. Many homes with two bathrooms need 5 to 7 GPM. Cold-climate homes need more capacity than warm-climate homes for the same flow.
Can a tankless water heater run out of hot water?
It won’t run out the way a tank does, but if you open more fixtures than the unit is sized for, the water temperature will drop. Proper sizing prevents this.
Is there a tax credit for tankless water heaters in 2026?
No federal tax credit applies to tankless water heaters installed in 2026. The Section 25C credit ended for property placed in service after December 31, 2025. Some gas utilities and local programs still offer rebates, so check with your utility.
Do I need a permit to install a tankless water heater?
In most US jurisdictions, yes. Gas line, venting and electrical changes typically require a permit and inspection. Permit fees usually range from about $50 to $300, and a licensed plumber normally pulls the permit for you.
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