Last updated: June 2026
Tankless water heater cost runs $1,400 to $5,600 installed, with most homeowners spending around $2,600 for a complete project. The price swings hard on one decision: gas vs. electric. Gas units cost more and often need venting and gas-line work, while electric units are cheaper to install but may require an electrical panel upgrade. The unit itself is only about 40–45% of the total — the rest is labor and the infrastructure changes a tankless conversion frequently demands.
This guide breaks down tankless water heater cost by fuel type, explains the hidden conversion costs that catch homeowners off guard, and helps you decide whether the switch from a tank pays off.
How Much Does a Tankless Water Heater Cost?
A tankless water heater costs $1,400 to $5,600 installed. Electric units run $1,400 to $3,000 and are cheaper and simpler to install. Gas units run $2,100 to $5,600 because they need venting and often gas-line upgrades. The unit alone is $200 to $2,000; labor adds $600 to $2,500, plus more if infrastructure upgrades are required.
| Type | Unit Only | Installed Total |
|---|---|---|
| Electric tankless | $200 – $700 | $1,400 – $3,000 |
| Gas tankless (non-condensing) | $1,000 – $1,800 | $2,100 – $4,500 |
| Gas tankless (condensing) | $1,300 – $2,600 | $3,000 – $5,600 |
| Solar tankless | — | $1,800 – $5,700 |
| Single-point (one fixture) | $100 – $300 | $300 – $800 |
Gas vs. Electric Tankless: Which Costs Less?
Electric tankless water heaters cost 30–40% less to install than gas because they don’t need venting or gas lines. But there’s a catch: whole-house electric units pull enormous power and often require high-amperage dedicated circuits — sometimes a full electrical panel upgrade costing $850–$1,700. Gas units cost more upfront and need venting, but deliver higher flow rates (better for big households) and often lower operating costs.
The rule of thumb most plumbers follow: gas is generally superior for whole-house use in larger or colder-climate homes, while electric makes sense for smaller homes, apartments, or single-point applications where you’re heating water for one or two fixtures.
What Drives Tankless Water Heater Cost?
1. Fuel Type and Infrastructure
This is the big one. Converting from a tank to a tankless unit frequently triggers infrastructure upgrades the base quote doesn’t mention. Gas tankless units require higher BTU input than tank heaters, so existing gas lines often need upsizing ($350–$2,000), and old tank vents can’t be reused — new venting runs $100–$600. Electric units may need a dedicated circuit ($250–$900) or a panel upgrade. These are the costs that turn a $2,000 quote into a $4,000 reality.
2. Flow Rate (GPM)
Tankless capacity is measured in gallons per minute. Per the U.S. Department of Energy, tankless units deliver about 2–5 GPM, with gas producing higher flow than electric. A bigger household running multiple showers and appliances at once needs a higher-GPM unit, which costs more. Undersizing is the most common mistake — it leads to running out of hot water during peak demand.
3. Condensing vs. Non-Condensing
Non-condensing gas units cost about 25% less to install but vent hot exhaust without capturing extra heat, lowering efficiency. Condensing units extract additional heat from exhaust gases, running more efficiently with lower long-term energy bills — at a higher upfront price.
4. Labor and Location
Labor is 40–55% of the total for standard installs, more when infrastructure upgrades are involved. A simple swap takes 3–4 hours; a tank-to-tankless conversion takes 5–6 hours; complex jobs with gas or electrical upgrades take 7–8+ hours. Metro areas run above the national median; rural markets below.
The federal tax credit worth knowing about: ENERGY STAR certified gas tankless models with a Uniform Energy Factor (UEF) of 0.95 or higher qualify for a 30% federal tax credit, up to $600, under the Energy Efficient Home Improvement Credit. Most modern gas tankless units meet this threshold. The credit applies to equipment cost only (not labor). Many states and utilities offer additional rebates of $100–$1,000 — stacked together, these can cut $500–$1,500+ off your project.
Tankless Water Heater Cost Calculator
Tankless vs. Tank Water Heater: Is It Worth It?
A traditional tank water heater costs $1,200 to $2,400 installed — cheaper upfront than a gas tankless. So is tankless worth the premium? It comes down to how long you’ll stay and your hot water habits.
The case for tankless: it lasts 15–20 years vs. 8–12 for a tank, so you’ll likely replace it half as often, saving $1,400–$2,000 in avoided replacements over 20 years. The DOE reports tankless is 24–34% more efficient for low-usage homes (8–14% for high-usage). The break-even point is usually year 8–10, after which the savings are pure gain — and the federal tax credit accelerates that. If you’re selling within 5 years, though, a traditional tank often makes more financial sense. For a full comparison with standard tanks, see our water heater installation cost guide and water heater replacement cost guide.
Tankless Water Heater Maintenance Costs
Tankless units need annual flushing to prevent mineral buildup, especially in hard-water areas — budget $100 to $350 per year. Skipping maintenance shortens lifespan and can void warranties. In very hard water areas, a water softener ($500–$2,500) extends the unit’s life significantly. This ongoing cost is real but modest compared to the energy savings and longer lifespan.
The “Cold Water Sandwich” and Recirculation
One quirk of tankless units: the “cold water sandwich.” If you turn the tap off and back on quickly, the burner shuts off to save energy, then takes a moment to reignite — giving you a brief splash of cold water between hot. Modern units with a recirculation pump solve this by keeping hot water circulating in a loop, so it’s instantly available. A recirculation add-on runs from a few hundred dollars (crossover valve) to $1,200+ (dedicated return line in a retrofit).
How to Get a Fair Tankless Water Heater Quote
- Insist on a load calculation. A good installer calculates your peak GPM demand and verifies whether your gas meter, gas line, and electrical service can handle the unit. Skipping this leads to undersized units or surprise upgrade costs.
- Ask what infrastructure work is included. Gas line upsizing, new venting, dedicated circuits, panel upgrades — these should be spelled out, not discovered mid-project.
- Confirm permits. Most jurisdictions require a permit for water heater installation. Reputable plumbers include it; ask.
- Verify the warranty. Look for 10–15 years on the heat exchanger. Improper installation can void it, which is another reason to hire a licensed pro.
- Ask about the tax credit and rebates. Confirm the unit qualifies for the federal credit and ask the installer which local utility rebates apply.
Frequently Asked Questions About Tankless Water Heater Cost
How much does a tankless water heater cost installed?
A tankless water heater costs $1,400 to $5,600 installed. Electric units run $1,400–$3,000, gas non-condensing $2,100–$4,500, and gas condensing $3,000–$5,600. Most homeowners pay around $2,600. Infrastructure upgrades like gas line upsizing or panel upgrades push the total higher.
Is a gas or electric tankless water heater cheaper?
Electric tankless units cost 30–40% less to install because they don’t need venting or gas lines. However, whole-house electric units may require a dedicated high-amperage circuit or panel upgrade. Gas units cost more upfront but offer higher flow rates and often lower operating costs, making them better for larger households.
Is a tankless water heater worth the cost?
For homeowners staying 8+ years, usually yes. Tankless units last 15–20 years vs. 8–12 for tanks, are 24–34% more efficient for low-usage homes, and qualify for a 30% federal tax credit. The break-even is around year 8–10. If you’re selling within 5 years, a traditional tank often makes more financial sense.
Why is tankless water heater installation so expensive?
The unit is only 40–45% of the cost. The rest is labor and infrastructure: gas tankless units need higher-capacity gas lines and new venting (old tank vents can’t be reused), while electric units may need a dedicated circuit or panel upgrade. These conversion costs are what push the total up.
How long does it take to install a tankless water heater?
A simple swap of an existing tankless unit takes 3–4 hours. Converting from a tank to tankless takes 5–6 hours including old unit removal and venting. Complex installs requiring gas line upgrades, panel modifications, or extensive venting take 7–8+ hours.
Do tankless water heaters qualify for a tax credit?
Yes. ENERGY STAR certified gas tankless models with a UEF of 0.95 or higher qualify for a 30% federal tax credit, up to $600, under the Energy Efficient Home Improvement Credit. Most modern gas tankless units meet this. The credit applies to equipment cost only. Many states and utilities offer additional rebates.
How long does a tankless water heater last?
Tankless water heaters last 15–20 years with proper maintenance — nearly twice as long as the 8–12 years of a traditional tank. Gas units typically last 18–20 years, electric 15–18 years. Annual flushing, especially in hard-water areas, is essential to reaching the upper end of that range.
How much does it cost to convert from a tank to a tankless water heater?
Tank-to-tankless conversion typically costs $2,500 to $4,500 or more, depending on whether your gas line needs upsizing, new venting is required, or electrical upgrades are needed. The conversion is more expensive than a like-for-like swap because tankless units have different gas, venting, and electrical requirements than tanks.
What size tankless water heater do I need?
Size is based on peak GPM demand — how many fixtures run hot water at once. A small home needs ~2–5 GPM; a large household running multiple showers and appliances simultaneously needs a higher-GPM gas unit. A proper load calculation by your installer prevents undersizing, which causes running out of hot water during peak use.
Do tankless water heaters need maintenance?
Yes. Annual flushing to remove mineral buildup costs $100–$350 and is essential, especially in hard-water areas. Skipping maintenance shortens lifespan and can void the warranty. A water softener ($500–$2,500) in very hard water areas significantly extends the unit’s life.
