How Much Does It Cost to Install a Tankless Water Heater?
Tankless water heater installation costs $1,000–$5,000 depending on fuel type, unit size, and whether you're switching from a tank. Full cost breakdown, charts, and money-saving tips.
How Much Does Tankless Water Heater Installation Cost?
The average tankless water heater installation cost ranges from $1,000 to $5,000, depending primarily on whether you choose a gas or electric model, the size of the unit, and whether you're replacing an existing water heater or starting fresh. Most homeowners pay between $2,500 and $4,500 for a whole-home gas tankless installation when all costs are included.
That wide range can feel overwhelming, so this guide breaks down every cost component — equipment, labor, permits, and infrastructure upgrades — so you know exactly what to expect before you get a quote.
Note: These figures assume a licensed plumber does the work and include typical infrastructure upgrades. If you already have the right gas line size, venting, or electrical circuit, you'll land at the lower end of each range.
Need a plumber? Get free quotes from trusted local plumbers
Cost by Fuel Type: Side-by-Side Comparison
The biggest cost driver is fuel type. Gas units cost more upfront and require more complex installation, but they heat water faster and have lower operating costs in most regions.
Full Cost Breakdown: What You're Actually Paying For
Your total tankless water heater installation cost has four components. Understanding each one helps you evaluate quotes and spot where you might be able to save.
| Cost Component | Gas Tankless | Electric Tankless | Notes |
|---|---|---|---|
| Unit / Equipment | $700 – $1,800 | $300 – $700 | Higher flow rate = higher price |
| Labor (Plumber) | $1,500 – $3,000 | $750 – $1,500 | 4–8 hrs at $100–$200/hr |
| Venting / Exhaust | $300 – $1,000 | $0 | Electric units don't need venting |
| Gas Line Upgrade | $200 – $800 | $0 | Often needed (3/4" vs 1/2" line) |
| Electrical Upgrade | $0 | $300 – $1,000 | Whole-home units need 240V/150A+ |
| Permits & Inspection | $50 – $250 | $50 – $200 | Varies widely by municipality |
| Total (Typical Range) | $2,500 – $6,000 | $1,200 – $3,500 |
5 Factors That Affect Your Final Cost
1. Gas vs. Electric
Gas tankless units cost significantly more to install but typically cost less to operate, especially in regions where natural gas is cheap. Electric tankless units have simpler, less expensive installations but can drive up electricity bills — particularly in areas with high electricity rates. The U.S. Department of Energy estimates that tankless gas heaters can be 8–14% more energy-efficient than conventional storage gas heaters for homes using 86 gallons or more per day.
For a full comparison of how these types perform day-to-day, see our guide: Tank vs. Tankless Water Heaters.
2. Flow Rate (GPM) — The Most Important Sizing Factor
Tankless units are rated by gallons per minute (GPM). A unit rated at 6 GPM can handle one shower and one sink running simultaneously. A whole-home unit for a 4-bedroom house might need 9–11 GPM. Higher GPM = higher unit price.
- 1–2 bathrooms: 4–6 GPM gas unit ($700–$1,300); electric ($200–$600)
- 2–3 bathrooms: 6–9 GPM gas unit ($900–$2,000)
- 3+ bathrooms: 9–11 GPM gas unit ($1,200–$2,500)
Not sure what size you need? Our water heater sizing guide walks you through the calculation.
3. Condensing vs. Non-Condensing Gas Units
Gas tankless heaters come in two types, and this choice meaningfully affects installation cost:
- Non-condensing: Vents hot exhaust gases through a single stainless steel flue (similar to a furnace). Lower unit cost ($700–$1,300) but requires expensive stainless steel venting that can withstand high temperatures. Venting alone can add $500–$1,000.
- Condensing: Extracts more heat from combustion gases, exhausting them at a lower temperature. Can use cheaper PVC or CPVC venting (around $200–$400). Higher unit price ($1,000–$2,500) but lower overall installation cost when venting is factored in.
In most cases, condensing models offer a better total cost of ownership. They're also quieter and more efficient — typically achieving 0.90–0.96 UEF compared to 0.80–0.87 for non-condensing.
4. Switching from Tank to Tankless
If you're replacing a traditional tank water heater, expect to pay a conversion premium of $500–$2,000 on top of the standard installation cost. Here's why:
- Gas line upgrade: Tankless units need much more gas — a 1/2" supply line is often inadequate. Upgrading to 3/4" typically costs $200–$800.
- New venting: Tank heaters and tankless units use different venting configurations. Existing vent pipes often can't be reused.
- Electrical service: Even gas tankless units need a 120V outlet nearby. Electric tankless units require a 240V circuit, which may require panel upgrades.
- Old unit removal: Most plumbers charge $50–$150 to disconnect and haul away the old tank.
5. Location: Indoor vs. Outdoor Installation
Installing a tankless unit outdoors (where local climate permits) can eliminate venting costs entirely — outdoor units are already weatherproofed. This approach is popular in mild-climate states like California, Texas, and Florida.
- Outdoor installation: Saves $300–$1,000 in venting; unit price is similar or slightly higher
- Indoor installation: Required in cold climates; adds venting cost but protects the unit from the elements
Typical Labor Rates by Region
Labor is a significant variable. Plumbers in high cost-of-living cities charge substantially more than those in rural areas. Here's what to expect:
| Region | Plumber Hourly Rate | Typical Install Labor Total |
|---|---|---|
| Rural / Midwest | $75–$110/hr | $600–$1,200 |
| Southeast / Southwest | $100–$135/hr | $800–$1,600 |
| Northeast / Northwest | $125–$160/hr | $1,000–$2,200 |
| Major Metro (NYC, LA, SF, Boston) | $150–$200/hr | $1,500–$3,000+ |
Most installations take 3–5 hours for a straightforward same-fuel replacement, or up to 7–10 hours for complex conversions requiring new gas lines, venting, and electrical work.
Rebates and Tax Credits: Money on the Table
The upfront cost of a tankless water heater looks much better once you factor in available incentives.
Federal Tax Credit
Under the Energy Star Federal Tax Credit (extended through 2032 by the Inflation Reduction Act), you may be eligible for a tax credit worth:
- 30% of the cost (up to $600) for qualifying gas, electric, or propane tankless water heaters with a UEF ≥ 0.95
- This applies to both the unit and installation labor
On a $3,000 installation, that's $600 back — bringing your effective cost down to $2,400.
Utility Rebates
Many utility companies offer additional rebates of $50–$500 for installing Energy Star-qualified water heaters. Search for local rebates at DSIRE (Database of State Incentives for Renewables & Efficiency).
State-Level Programs
Some states offer their own rebate programs on top of federal credits. California, Massachusetts, Oregon, and New York tend to have the most generous state programs. Check your state energy office or use the DSIRE database above.
- Gas condensing tankless unit (Navien NPE-240A2): $1,200
- Plumber labor (6 hrs × $130/hr): $780
- PVC venting: $350
- Gas line upgrade: $400
- Permit: $150
- Gross total: $2,880
- Federal tax credit (30%): −$600
- Utility rebate: −$200
- Net cost: ~$2,080
How Long Until It Pays for Itself?
Tankless water heaters are more expensive upfront but cheaper to operate. Here's how to think about the payback period.
According to the U.S. Department of Energy, tankless water heaters are 24–34% more energy-efficient than traditional storage tanks for homes using 41 gallons or less per day, and 8–14% more efficient for high-usage homes. The average American household spends about $400–$600/year heating water.
Based on DOE estimates. Actual savings vary by fuel cost, usage habits, and climate.
At $100/year in energy savings, a $2,500 installation (after incentives: $1,750) has a payback period of about 17 years. That sounds long — but tankless heaters last 20+ years, giving you 3+ years of savings beyond break-even. A traditional tank heater lasts only 8–12 years and you'd be paying for a replacement in that same window. For a detailed breakdown of the lifetime cost comparison, see Tank vs. Tankless Water Heaters.
Top Brands and What They Cost
Brand choice significantly affects both unit price and installation complexity. Here are the most widely installed brands and typical pricing:
| Brand | Unit Price Range | Best Known For | Check Your Unit's Age |
|---|---|---|---|
| Rinnai | $700 – $1,600 | Reliability, wide contractor support | Rinnai Age Checker |
| Navien | $900 – $1,800 | High efficiency, built-in recirculation | Navien Age Checker |
| Rheem | $600 – $1,400 | Wide availability, easy to service | Rheem Age Checker |
| Noritz | $650 – $1,500 | Japanese engineering, long lifespan | Noritz Age Checker |
| Takagi | $550 – $1,300 | Commercial-grade durability | Takagi Age Checker |
| Bosch | $200 – $900 | Affordable electric point-of-use | Bosch Age Checker |
6 Ways to Save Money on Your Installation
1. Get Three Quotes
Plumber quotes for the same job can vary by 30–50%. Always get at least three written quotes before committing. Make sure each quote includes the same scope of work so you're comparing apples to apples.
2. Buy the Unit Yourself
Plumbers typically mark up equipment 15–40%. Purchasing your own unit from a wholesale supplier or home improvement store and supplying it to the plumber can save $150–$500. Just confirm your plumber is willing to install customer-supplied equipment — some charge a surcharge, but it's usually still cheaper than their markup.
3. Choose an Outdoor Model (If Climate Allows)
If you live in a region that doesn't experience freezing temperatures, an outdoor tankless unit eliminates all venting costs. Rinnai, Navien, and Noritz all make outdoor models. Savings: $300–$1,000 on venting materials and labor.
4. Avoid Peak Season
December through February is the busiest time of year for plumbers (emergency water heater calls spike). April through September tends to have more availability and, in some markets, lower rates. Planning a non-emergency replacement in the off-season can save 10–20% on labor.
5. Claim Every Rebate
The federal tax credit, utility rebates, and state programs can collectively reduce your net cost by $500–$1,200. Ask your plumber if they've done the rebate paperwork before — experienced installers often know which units qualify and can help you file.
6. Check If Your Current Infrastructure Is Compatible
Before getting quotes, check whether you already have:
- A 3/4" gas supply line (avoids a $200–$800 upgrade)
- Existing appropriate venting in a compatible location
- A 240V circuit with enough amperage (for electric models)
If you can avoid any one of these upgrades, you'll save several hundred dollars. Your plumber should assess this during the quoting visit.
Should You DIY a Tankless Water Heater Installation?
Technically, a homeowner can install their own water heater in some states — but tankless water heaters are far more complex than traditional tanks. Here's what you should know:
- Permits are almost always required. Most municipalities require a permit and licensed inspection for water heater replacements. Unpermitted work can void your homeowner's insurance and create problems when you sell.
- Gas work requires a licensed plumber in most states — it's illegal (and dangerous) for homeowners to modify gas lines.
- Electric whole-home units require a licensed electrician for panel work and wiring in most jurisdictions.
- Manufacturer warranties often require professional installation. A DIY install could void the 10–15 year heat exchanger warranty.
Bottom line: Unless you're a licensed plumber or electrician, this is one installation to leave to the professionals. The permit and warranty exposure make DIY risky even if you have the mechanical skill.
Is a Tankless Water Heater Worth the Cost?
For most homeowners, a tankless water heater is worth the investment if:
- Your current water heater is 10 or more years old — use our free water heater age checker to find out
- You plan to stay in your home for at least 8–10 years
- You want endless hot water and run out frequently with your current tank
- You qualify for federal tax credits and utility rebates that offset the higher upfront cost
- You want to free up space — tankless units are wall-mounted and compact
It may not be worth it if you're planning to sell within 5 years, since you're unlikely to recoup the installation premium in a home sale. In that case, a standard tank water heater replacement at $800–$1,500 installed is usually the smarter short-term choice.
For help comparing options for your specific home, see Should You Repair or Replace Your Water Heater?
Frequently Asked Questions
What is the average cost to install a tankless water heater?
The national average total tankless water heater installation cost is $2,500–$3,500 for a gas model and $1,500–$2,500 for a whole-home electric model. This includes the unit, labor, venting or electrical work, and permits. High-end installations in major metros or requiring significant infrastructure upgrades can reach $5,000 or more.
How much does it cost to replace a tank water heater with a tankless?
Switching from a tank to tankless costs $2,500–$6,000 for gas and $1,500–$4,000 for electric — premium above a same-type replacement because of gas line upgrades, new venting, and possible panel work. The closer your existing setup is to what the new tankless unit needs, the lower your conversion cost.
Are tankless water heaters worth the extra cost?
Over a 15–20 year lifespan, most homeowners break even on the higher installation cost through energy savings and avoiding a mid-life tank replacement. They deliver the added benefit of never running out of hot water. Homes that use less than 41 gallons per day see the biggest efficiency gains — up to 34% according to the U.S. Department of Energy.
How long does tankless water heater installation take?
A simple same-fuel swap (gas tank to gas tankless, same location) typically takes 3–5 hours. Conversions requiring new gas lines, venting, or electrical work can take 6–10 hours, sometimes spread over two visits (rough-in on day one, inspection and final connection on day two).
Do I need a permit to install a tankless water heater?
In most U.S. jurisdictions, yes — a permit is required for water heater replacement. Permit costs range from $50 to $250. Reputable plumbers pull permits as a matter of course. Be wary of any contractor who suggests skipping the permit — unpermitted work can create insurance issues and problems when you sell your home.
How often does a tankless water heater need to be serviced?
Gas tankless units should be flushed and descaled annually if you have hard water, or every 2–3 years in areas with soft water. Annual service runs $100–$250. Ignoring descaling is the leading cause of premature tankless water heater failure. For more on spotting problems early, see Signs Your Water Heater Is About to Fail.
What is the lifespan of a tankless water heater?
A properly maintained tankless unit typically lasts 15–20 years — roughly twice as long as a traditional tank. Parts like the heat exchanger are often replaceable, which can extend the life even further. First, check how old your current water heater is before deciding whether to repair or replace.
Ready to move forward? Start by checking your current water heater's age — it takes 30 seconds. If it's approaching 10 years, this is the right time to start getting quotes before you're forced into an emergency replacement. Our Replacement Cost Calculator can help you estimate and compare options for your specific home.