Tankless Water Heater Install: $600 to $1,900 Labor (2026)
Tankless water heater installation labor runs $600 to $1,900 in HomeAdvisor's 2026 data, against $150 to $450 to swap one tank for another, and Angi's 2026 labor range is $600 to $1,850.
Retrofit work adds to that: HomeGuide puts a larger gas line at $350 to $2,000, first-time venting at $500 to $1,500 and a dedicated circuit at $250 to $900.
Key numbers
- $2,641Tankless installed, averageHomeAdvisor, June 2026
- $1,400 to $5,600Tankless installed, rangeHomeGuide, Jan 2026
- $3,500 or moreNew gas lines when switching from electric or oilFixr, Jan 2026
Tankless water heater installation is mounting an on-demand water heater that heats water as it flows instead of storing it, plus the gas, venting or electrical work it needs, and it averages $2,641 installed in HomeAdvisor's 2026 data.
This page covers tankless only. For tank and heat pump water heaters, repair costs and permits, see water heater replacement cost.
Tankless water heater installation cost: labor and retrofit work
No hot water, or water around the tank? Call the water heater line. A local plumber answers and quotes the service call first.
| What | Published price | Source |
|---|---|---|
| Tankless installed, average | $2,641; typical $1,406 to $3,902 | HomeAdvisor, June 2026 |
| Tankless installed, range | $1,400 to $5,600 | HomeGuide, Jan 2026 |
| Tankless installed, range | $1,600 to $4,000, close to twice a tank | Fixr, Jan 2026 |
| Labor, tankless | $600 to $1,900 (vs $150 to $450 for a tank swap) | HomeAdvisor, June 2026 |
| Labor share of a tankless job | About 50% of the total, $800 to $2,000 | Fixr, Jan 2026 |
| New vent | $500 (direct vent) to $1,100 (power vent) | Fixr, Jan 2026 |
| New gas lines when switching from electric or oil | $3,500 or more | Fixr, Jan 2026 |
| Permit and inspection for a new gas line | Can reach $1,500 or more | Fixr, Jan 2026 |
| Tankless repair, for comparison | $300 to $1,300; heat exchanger $600 to $1,300 | HomeGuide, Aug 2025 |
Published US installed prices. The spread between the guides comes mostly from retrofit work: venting, gas piping and electrical.
Pricing a tankless swap? Call the water heater line with your current tank's fuel and size, and whether the new unit would go in the same spot.
Fixr says tankless runs "close to twice as much" as a tank, and the reason is labor. HomeAdvisor puts tankless labor at $600 to $1,900 against $150 to $450 for swapping one tank for another, and Fixr says labor is about half of a tankless job. A tank swap reuses what is already there. A tankless retrofit usually changes the gas line, the vent or the electrical circuit, sometimes all three.
Why tankless retrofits cost more than a tank swap
Venting
A gas tankless unit burns a lot of gas for short bursts and often needs a new vent rather than the old tank's flue. Fixr prices a new vent at $500 for a direct vent to $1,100 for a power vent. Where the unit sits matters: an outside wall close to the old tank keeps the vent run short.
Gas line upsizing
A tank heats slowly with a small burner. A tankless unit heats water instantly, so it draws far more gas at once, and the existing line may be too small. The installer has to check the line size and the run back to the meter. If the house is switching from electric or oil to gas, Fixr says new gas lines can add $3,500 or more, and the permit and inspection for a new gas line can reach $1,500 or more.
Electrical for electric tankless
An electric tankless unit has no vent, but it needs a lot of power. HomeAdvisor says a whole-house electric tankless needs "240V 80 amp hard-wired electrical service at a minimum" and a home with at least 150 amp service. In an older house with a smaller panel, that can mean an electrical panel upgrade before the heater goes in. An electrician runs the circuit; see the electrician page if you need one for the panel side.
Gas vs electric tankless water heater
| Gas tankless | Electric tankless | |
|---|---|---|
| What it needs | Gas supply sized for the unit, a dedicated vent to the outside, an electrical outlet for controls | A large dedicated electrical circuit; HomeAdvisor says whole-house units need 240V, 80 amp hard-wired service at a minimum |
| Common retrofit add-ons | New vent ($500 to $1,100, Fixr); larger or new gas line | New circuit; a panel upgrade if the home is under 150 amp service (HomeAdvisor) |
| Who does the work | Plumber, often with a gas permit | Plumber plus an electrician for the circuit |
Requirements from HomeAdvisor's tankless guide and Fixr's gas water heater guide.
If the house already has gas at the water heater, gas tankless is the usual choice for a whole-house unit, and the vent and line size are the questions to settle. If it does not, compare the cost of new gas lines ($3,500 or more, per Fixr) with the cost of the electrical work. Either way, get the gas or electrical assessment done before you choose a model.
How long does a tankless water heater last
DOE says a tankless unit lasts about 20 years, against 10 to 15 for a storage tank, and is 8% to 34% more efficient. HomeAdvisor gives the same 20 years for tankless and 8 to 12 for a conventional tank. Scale buildup is a known problem: Rheem says whistling or hissing from a tankless unit points to scale. Regular descaling keeps the heat exchanger working; replacing a heat exchanger runs $600 to $1,300 (HomeGuide), and tankless repairs overall run $300 to $1,300.
Is a tankless water heater worth it
The trade is clear in the published numbers. Tankless costs about twice as much to install (Fixr), lasts about 20 years against 10 to 15 for a tank, and is 8% to 34% more efficient than a storage tank (DOE). It is the stronger case when the house already has gas and a good spot for venting, when you plan to stay long enough to use the longer life, and when hot water running out is a daily problem. It is the weaker case when the retrofit needs new gas lines or a panel upgrade, or when the tank failed today and you need hot water tonight. A like-for-like tank swap, covered on the replacement cost page, is faster and needs fewer changes.
The federal credit that once applied to some efficient water heaters (25C) does not cover property placed in service after December 31, 2025, per the IRS. Check your state and gas or electric utility for rebates.
Want a company to check your gas line, vent route or panel before you commit to tankless? Call the water heater line and ask for a tankless assessment.
Tankless water heater installation near me: what to ask
- Is my gas line big enough, or what electrical service do I need? Ask for the answer in writing, with the cost of any upgrade.
- Where will the vent run? Ask for the vent type (direct or power vent) and route.
- Who handles the electrical work? For electric units, and for gas units near a panel that needs a circuit, ask whether an electrician is included.
- Who pulls the permits? A new gas line or circuit usually needs its own permit and inspection.
- Is haul-away of the old tank included?
- What maintenance does the warranty require? Ask how often the unit needs descaling and whether the company offers it.
- Which license does the work need here? Rules vary by state and city; ask for the license number and check it with the state board.
If the old tank is leaking now, shut off its water supply if you can reach the valve safely and check for spread into floors or walls; leak detection covers finding hidden water. Calls go to an independent company that serves your area and takes water heater work. How calls work.
More plumbing guides
Tankless retrofit add-on costs, line by line
A tank-to-tankless retrofit adds $600 to $2,500 in labor alone in HomeGuide's 2026 guide, plus whichever of these the house needs:
| Retrofit item | Published price | Source |
|---|---|---|
| Labor, tank to tankless | $600 to $2,500; half to a full day | HomeGuide, Jan 2026 |
| Labor, typical install | $600 to $1,850; about 3 hours | Angi, Aug 2026 |
| Installation materials | $130 to $280, plus about $10 a foot of piping and insulation | Angi, Aug 2026 |
| Larger gas supply line | $350 to $2,000 | HomeGuide, Jan 2026 |
| Venting, first-time install | $500 to $1,500 ($100 to $600 to replace existing vents) | HomeGuide, Jan 2026 |
| Dedicated electrical circuit | $250 to $900 | HomeGuide, Jan 2026 |
| Electrical panel replacement | $850 to $1,700 | HomeGuide, Jan 2026 |
| Electric-to-gas conversion | $400 to $2,000 or more | HomeGuide, Jan 2026 |
| Permits for gas or electrical work | $50 to $200 | HomeGuide, Jan 2026 |
HomeGuide water heater installation guide (January 2026) and Angi tankless guide (August 2026).
For the price of the heater itself, the cost by flow rate and how to size one, see how much a tankless water heater costs.
Questions people ask
How much does it cost to install a tankless water heater?
HomeAdvisor's 2026 average is $2,641, typically $1,406 to $3,902. HomeGuide gives $1,400 to $5,600 and Fixr $1,600 to $4,000.
Why is tankless installation so expensive?
Labor and retrofit work. HomeAdvisor puts tankless labor at $600 to $1,900 against $150 to $450 for a tank swap, and a new vent adds $500 to $1,100 (Fixr). Switching to gas can add $3,500 or more for new lines.
Does an electric tankless water heater need a panel upgrade?
It can. HomeAdvisor says a whole-house electric tankless needs 240V, 80 amp hard-wired service at a minimum and a home with at least 150 amp service.
How long does a tankless water heater last?
About 20 years, per DOE and HomeAdvisor, against 10 to 15 years for a tank (DOE). Descaling in hard-water areas helps it get there.
Is gas or electric tankless better?
Gas is the usual whole-house choice where gas is already at the heater; it needs a vent and an adequately sized gas line. Electric skips the vent but needs a large 240V circuit and enough panel capacity.
Is tankless worth it over a tank?
It costs close to twice as much installed (Fixr) but lasts about 20 years against 10 to 15 and is 8% to 34% more efficient (DOE). It pays best when gas and venting are already in place.
How long does it take to install a tankless water heater?
Angi says about three hours in typical cases; HomeGuide says a tank-to-tankless upgrade usually takes half to a full day, and a new install up to 10 hours.
Ready to price tankless for your house? Call the water heater line and say gas or electric, and where the current tank sits.
- 1Call the line
- 2It rings a local company
- 3They give you the price
Before you book
- License numberAsk for it, then check it with the state board.
- Written priceGet the visit fee and the job price in writing before work starts.
- Proof of insuranceAsk for the certificate, especially for roof, tree and electrical work.
Sources (8)
- HomeAdvisor: How Much Does a Tankless Water Heater Cost? (2026-06-17)
- HomeGuide: How Much Does Water Heater Installation Cost? (2026) (2026-01-02)
- Fixr: How Much Does It Cost to Install a Gas Water Heater? (2026-01-30)
- DOE: Which Water Heater Is Right for You? (checked 2026-10-11)
- Rheem: 5 Signs Your Water Heater Is Going Bad (2025-12-22)
- HomeGuide: How Much Does Water Heater Repair Cost? (2026) (2025-08-07)
- IRS: FAQs for modification of sections 25C, 25D and others under Public Law 119-21 (FS-2025-05) (2025-08-21)
- Angi: How Much Does a Tankless Water Heater Cost? [2026 Data] (2026-08-03)
Talk to a plumber who serves your area
Have the address, gas or electric, the tank size or model from the label, its age, and what it is doing. The company will quote its service call fee first.
Free call to an independent company in your area that takes this kind of work.