How Much Does a Tankless Water Heater Cost to Install?

By the HomePriceFacts Research Team · Last updated: November 13, 2026 · Prices checked against published 2026 tankless water heater cost data

A tankless water heater costs $1,400 to $5,600 installed in 2026 — and the reason quotes for the same house swing across that whole range is that "installation" means different things to different bidders. One quote covers a like-for-like swap of an old tankless unit. Another covers a full tank-to-tankless conversion with a new gas line, new venting and a panel upgrade. Both are honest quotes for different jobs, which is why this guide prices the unit, the labour and every conversion add-on separately, and shows exactly where the two biggest cost publishers — Angi and HomeGuide — agree and where they measure different scopes.

The first thing to understand is what a tankless water heater actually is, because the price only makes sense once the product is clear. A tankless — or on-demand — unit has no storage tank. It heats water directly as it flows through a heat exchanger, using a gas burner or high-powered electric coils, and it stops heating the moment the tap closes. That is the whole pitch: endless hot water, no tank losing heat all day, and a unit roughly the size of a small suitcase mounted on a wall instead of a 50-gallon cylinder on the floor. It is also the whole complication: heating water instantly, at the flow rate a shower demands, takes far more power than keeping a tank warm, which is why the installation so often needs a bigger gas line, a new vent or a panel upgrade — and why the cheapest quote is usually the one that has quietly left those out.

The second thing to know is that the two publishers' headline numbers are both real and both useful, once you know what each one counts. Angi's guide, updated August 3, 2026, prices the installed job at $1,404–$3,904 with a $2,641 average across its verified projects. HomeGuide's guide, published January 2, 2026, prices the same job at $1,400–$5,600. The overlap at the bottom — both start at $1,400 — is the electric like-for-like swap, the cheapest whole-home job. The divergence at the top is the conversion: HomeGuide prices the gas-line, venting and electrical work that a tank-to-tankless switch needs, and Angi prices it separately in its own add-on lines. Neither source is wrong; they are answering slightly different questions, and this guide keeps them separate so you can see which one matches your house.

What the price normally includes

• Tankless unit — $600–$2,600 (HomeGuide); Angi prices units at $200–$2,000 depending on size and fuel
• Installation labour — $600–$2,500, typically 3–10 hours of plumber, electrician or installer time (HomeGuide); Angi puts labour at $600–$1,850 for around three hours
• Venting — new venting $100–$600 (HomeGuide); a termination vent kit alone is $40–$100 (Angi). The old tank heater's vent cannot be reused
• Gas line — $350–$2,000 to upgrade to a larger diameter line, or up to $2,000 for a new line where the home had none (HomeGuide)
• Dedicated electrical circuit — $250–$900 (HomeGuide)
• Permits — $50–$200 (HomeGuide); Angi prices work permits at $50–$100
• Old tank removal and disposal — $75–$500 (HomeGuide); Angi prices removal at $500 or more depending on size and access
• Materials and supplies — $130–$280 plus about $10 per linear foot for piping and insulation (Angi); HomeGuide prices additional supplies at $150–$300
• NOT usually included: electrical panel upgrade ($850–$1,700), pressure regulator replacement ($250–$350), power-source conversion ($200–$400), water treatment for hard water, or a recirculation pump

Tankless water heater cost by fuel type

Fuel type is the single biggest price decision, and it cuts both ways. Electric units are the cheapest to buy and the simplest to install — no venting, no gas line, no combustion — which is why the electric band starts at $1,400. But electric units have the lowest flow rates (Angi caps them at around 2 GPM for small units) and the highest running costs in most markets: HomeGuide prices annual energy at $340–$540 for an electric tankless against $220–$480 for gas. Gas units cost more up front and need venting and a gas line, but they heat more water faster, perform better in cold climates, and cost less to run. Propane sits between the two on price and is the answer for rural homes without a natural gas line — though the fuel itself costs more per year, roughly $350 against gas at roughly $200 on Angi's figures. Angi's installation-side figures run lower than HomeGuide's all-in table — electric $800–$1,500, gas $1,000–$1,500, propane $1,000–$1,500 to install — because they price the install work rather than the unit-plus-install job; budget against HomeGuide's table above, and treat Angi's as the labour slice inside it. Solar tankless is the outlier: $1,800–$5,700 on Angi's figures, with some systems over $13,000, and it is a different product — a solar water heater with a tankless backup — not a like-for-like alternative to a gas or electric unit.

Cost by size: gallons per minute

Size a tankless unit by flow rate, not by the price tag. HomeGuide's rule of thumb is 3.5 GPM as the minimum for one to two fixtures running at once, 5 GPM for two to three fixtures, and 7 GPM or more for three to four fixtures. Angi puts the average home's need at 5.5 to 7.5 GPM. The practical test is the morning peak: a standard shower head draws 4–6 GPM, an eco shower head 2–3 GPM, a faucet 1–2 GPM, a washing machine 2–2.5 GPM and a dishwasher 1.5–2 GPM. Add up what runs at the same time in your house and buy that much flow — a unit that is too small runs cold when two showers run together, and a unit that is too large costs more up front for capacity you never use. Gas units are sized in BTUs as well: Angi prices smaller gas heaters of 120,000–140,000 BTU at $500–$1,200, enough for a one- or two-bedroom home, and larger units of 180,000–200,000 BTU or more at $900–$2,200 for homes of five or more people. Electric units are sized in kilowatts: 5–8 kW at $100–$250 for a one-bedroom apartment, 10–24 kW at $210–$630 for a two-bedroom home, and 27–36 kW at $420–$800 for a large home.

What the installation actually costs

The unit itself is only about 40–45% of the total project cost on HomeGuide's figures — the rest is labour, supplies and permits, which is why two quotes for the same unit can sit $2,000 apart. Labour is the swing factor: $600–$2,500 for 3–10 hours, depending on the installer's experience, the difficulty of the job, and whether gas or electrical upgrades are included. Angi's labour band is narrower, $600–$1,850 for around three hours, which matches a straightforward swap; HomeGuide's wider band covers the conversion jobs that take a full day. Labour rates themselves vary by trade: HomeGuide prices a plumber or HVAC technician at $75–$150 an hour and an electrician at $50–$130 an hour, while Angi's plumber band is $45–$200 an hour depending on licence level and local demand. Our plumber hourly cost guide prices those rates by licence level, which is the check to run against any quote that bundles labour into a single line.

Conversion add-ons: where the quote grows

This table is the whole reason the queue title for this guide talks about quotes swinging: a $1,400 electric swap and a $5,600 gas conversion are both real prices for the same category of product, and the difference is entirely in these lines. A gas conversion needs a larger gas supply line and new venting, because the old tank heater's vent cannot be reused for a tankless unit — condensing units need special PVC venting and a condensate drain, which is more complex and more costly than the metal vent a tank used. An electric conversion needs a dedicated circuit and may need a full panel upgrade if the service cannot carry a 27–36 kW load; our EV charger installation guide prices the same panel-upgrade work, which is the check to run if a quote bundles it. Moving the heater to a new location adds re-piping and re-venting on top, and a home with low water pressure may need a pressure regulator replacement at $250–$350. The two sources disagree on old-tank removal — HomeGuide at $75–$500, Angi at $500 or more — because removal cost depends on the tank's size and accessibility; confirm in writing whether the quote includes removal and disposal before you compare it with another.

What drives the price up or down

Fuel type

Electric is cheapest to install and most expensive to run; gas is the reverse. The fuel decision is really a household-size decision: a small household with modest hot-water use can live happily on an electric unit at $1,400–$3,000 installed, while a large household with simultaneous showers needs gas flow rates and will pay $2,100–$5,600 for them. Propane is the rural answer where no gas line exists, and solar is a different product class altogether.

Size and flow rate

Every GPM of capacity costs money, and the jump from a 3–4 GPM unit ($300–$700) to a 7–8 GPM unit ($500–$1,500) is the price of running two showers at once. Buy the flow rate your morning peak actually needs — add up the fixtures that run together — and do not pay for capacity your household never uses. Cold incoming water in northern states needs a bigger unit for the same fixtures, because the temperature rise required is larger: HomeGuide's example is groundwater at 50°F heated to 115°F, a 65°F rise, and colder groundwater pushes that rise — and the unit size — up.

Conversion vs like-for-like swap

Replacing an existing tankless unit with a similar one is the cheapest job: the gas line, venting and electrical work are already in place, and Angi prices a tankless-for-tankless replacement at $600–$1,900 in labour terms. Converting from a tank is the expensive job — HomeGuide prices conversion labour alone at $600–$2,500, and the gas line, venting and panel work on top of that. Installing during new construction is cheaper than retrofitting into existing plumbing for the same reason: access is open and nothing has to be re-routed.

Venting and the gas line

Gas tankless units vent hot exhaust gases, and the venting is not optional or reusable. Condensing units — the more efficient type — use a second heat exchanger to capture heat from the exhaust, which needs special PVC venting and a condensate drain. Non-condensing units are about 25% cheaper to install on HomeGuide's figures, but they vent hot exhaust without extracting the extra heat, which means higher energy bills over time. The gas line is the other hidden line: a tankless unit draws far more gas at peak than a tank heater, so the supply line often has to be upsized, at $350–$2,000.

The electrical panel

Electric tankless units are the most power-hungry appliances in most homes — a large unit can draw 27–36 kW, more than the rest of the house combined at peak. If the panel cannot carry that load, the upgrade runs $850–$1,700, plus $250–$900 for the dedicated circuit. This is the line that most often turns a $1,400 quote into a $3,000 one, and it is the line most often missing from the cheapest bid.

Condensing vs non-condensing

Condensing units cost more and run more efficiently; non-condensing units cost about 25% less to install and more to run. The choice is a payback calculation, not a quality judgement: in a household with heavy hot-water use, the condensing unit's efficiency pays back the premium; in a light-use household, the cheaper unit wins. Both are the same product category — do not let a quote present the condensing premium as a different tier of heater.

Climate and temperature rise

Temperature rise — the difference between incoming cold water and the target hot water temperature — decides how hard the unit works. Colder climates have a greater temperature difference, requiring a more powerful heater for the same fixtures. A 7 GPM unit that is ample in Florida can be undersized in Minnesota for the same household, which is one reason national averages hide real regional spreads.

Labour, permits and access

Labour is roughly half the project on Angi's figures, and it varies with the installer's experience, the difficulty of the job and local rates. Permits are small — $50–$200 — but they pay for the inspection that confirms the install is code-compliant, and an unpermitted install can surface at a home sale or an insurance claim. Difficult access — a narrow utility closet, a unit mounted outdoors, a long vent run — can add 10–15% to the labour cost.

Tank vs tankless: the honest comparison

Tankless costs roughly double up front, lasts roughly twice as long, and uses less energy in most households — but the savings are modest, not dramatic. On gas, the annual energy saving is small ($220–$480 against $250–$420); on electric it is real ($340–$540 against $530–$600). The bigger saving is lifespan: one tankless unit outlasts almost two tanks, which is where the maths starts to favour tankless for households staying 10-plus years. HomeGuide claims the investment can be recouped in 3 to 7 years through rebates and energy savings — that is HomeGuide's own claim, not a second-source figure, and it depends on rebates that no longer exist at the federal level, so treat it as optimistic. Our water heater replacement guide prices the tank side of this decision in full, including the heat-pump (hybrid) option that neither source covers here.

The federal tax credit is gone — and both sources still show it

The federal 25C Energy Efficient Home Improvement Credit ended for equipment placed in service after December 31, 2025, under the One Big Beautiful Bill Act (IRS Fact Sheet FS-2025-05). That matters here because both lead sources are stale on this point: HomeGuide still states that ENERGY STAR-certified gas tankless water heaters are eligible for a 30% federal tax credit up to $600, and Angi's guide still describes tax credits as available and claims a 30% credit for solar-powered units. Neither claim is true for a 2026 installation. Do not let a quote or a product page subtract a federal credit that no longer exists — check your utility and state programmes instead, and the DSIRE database for what is actually live in your state.

Ways to keep the cost down

• Choose electric if your household is small and your panel has capacity — it is the cheapest installed band at $1,400–$3,000, with no venting or gas line to pay for.
• Size by GPM, not by guess — buy the flow rate your morning peak actually needs, and do not pay for capacity you never use.
• Keep the old location — moving the heater to a new spot adds re-piping, re-venting and labour that a same-location swap avoids.
• Consider a non-condensing unit if your hot-water use is light — it costs about 25% less to install, and the efficiency gap only matters at high usage.
• Get three written quotes for the same scope, and require every bidder to list the gas line, venting, circuit and panel work as separate lines — a quote that omits them is not cheaper, it is incomplete.
• Check utility rebates before you buy — the federal credit is gone, but state and utility programmes still exist, and eligibility often requires specific models.

Frequently asked questions

Related cost guides

Sources: Angi, "How Much Does a Tankless Water Heater Cost? [2026 Data]" (updated August 3, 2026; average $2,641, range $1,404–$3,904; small electric units from $380; single-point $100–$300, whole-house unit $450–$1,500; GPM unit costs 1–2 $150–$250, 2–3 $200–$600, 3–4 $300–$700, 5–6 $400–$1,200, 7–8 $500–$1,500, 8+ $600–$2,000; installation by fuel — electric $800–$1,500, gas $1,000–$1,500, propane $1,000–$1,500, solar $1,700–$6,000; labour $600–$1,850; plumbers $45–$200/hr; permits $50–$100; old heater removal $500+; power-source conversion $200–$400; pressure regulator $250–$350; materials $130–$280 plus $10 per linear foot; gas 120–140k BTU $500–$1,200, 180–200k BTU $900–$2,200; electric 5–8 kW $100–$250, 10–24 kW $210–$630, 27–36 kW $420–$800; solar $1,800–$5,700; gas running ~$200/year, propane ~$350/year; average home 5.5–7.5 GPM. Angi's tax-credit claims are stale — flagged on-page); HomeGuide, "How Much Does a Tankless Water Heater Cost?" (January 2, 2026; $1,400–$5,600 installed; electric $1,400–$3,000, unit $600–$1,000; propane $1,600–$4,500, unit $1,000–$2,000; natural gas $2,100–$5,600, unit $1,500–$2,600; unit 40–45% of total; install extras $800–$3,000; labour $600–$2,500, 3–10 hours; dedicated circuit $250–$900; panel upgrade $850–$1,700; gas line $350–$2,000; vent replacement $100–$600; permits $50–$200; old tank removal $75–$500; conversion labour $600–$2,500; tank $600–$3,100 installed; annual energy tankless gas $220–$480, electric $340–$540 vs tank gas $250–$420, electric $530–$600; lifespan 15–20 vs 8–12 years; non-condensing ~25% cheaper to install; point-of-use $150–$250; sizing 3.5 GPM / 5 GPM / 7+ GPM; plumber/HVAC $75–$150/hr, electrician $50–$130/hr; 3–7 year payback claim is HomeGuide's own, labelled. HomeGuide's 30% tax-credit claim is stale — flagged on-page); NerdWallet 2026 guide (via 1-800deals, October 20, 2026; tankless $1,400–$3,900; Home Depot average $4,300 tankless vs $1,950 tank — noted, not used as a price row). NOT used: the queue title's "$2,800–$6,400" swing — published by no source found in this pass, so the title was retitled to the verified $1,400–$5,600; no state-level tankless averages were verified — no state table is published. Full source list and methodology: How we research. Spotted a price that looks wrong in your area? Tell us — we re-check reader-flagged figures first.