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How much does gas tankless water heater installation cost in Illinois?
Updated September 2026 · Illinois price index 1.32 for plumbing work (national = 1.00)
In Illinois, a licensed plumber typically charges $1,300 to $7,400 to install a gas tankless water heater in place of a tank, with most jobs landing near $3,700. That is about 32% above the national average of $1,000–$5,600, based on what plumbers earn in Illinois.
AI-powered second opinion using these same Illinois figures. No account, no card. Need someone to do the work? Verified pros in Illinois took the Fair Price Pledge.
What a Illinois quote means
| Quote for this job | What it means |
|---|---|
| Under $780 | Suspiciously low — ask what is excluded, and check licensing and insurance |
| $780 – $8,140 | Fair price — inside the typical range (up to 10% over the top is still normal) |
| $8,140 – $12,950 | Running high — get the quote itemized, and get a second one |
| Over $12,950 | Ripoff territory — more than 1.75× the high end of the typical range |
Same rules the QuoteJury checker uses on every quote.
What you're paying for
What is usually included: The tankless unit, new stainless venting, gas line upsizing if needed, isolation valves, condensate drain, removal of the old tank, permit, and 4–8 hours of labor.
What moves the price:
- Gas line size — most tanks run on a 1/2-inch line and tankless units often need 3/4-inch, which can add $500–$1,500
- Venting: condensing units use cheaper PVC venting than non-condensing stainless
- Unit size (GPM) matched to the number of bathrooms
- Electrical outlet needed near the unit, and a recirculation pump if requested
- Permit and inspection
Whether the gas line and venting must be upsized/rerouted (biggest swing), BTU capacity, condensing vs non-condensing unit, electrical outlet for the unit, permit, and old tank removal.
Gas tankless water heater installation cost across Illinois
Typical range by metro and rural area, from BLS wage data for plumbers in each area.
| Area | Typical range | Most jobs |
|---|---|---|
| Bloomington, IL | $1,150 – $6,300 | $3,200 |
| Champaign-Urbana, IL | $1,250 – $7,100 | $3,550 |
| Chicago-Naperville-Elgin, IL-IN | $1,350 – $7,600 | $3,800 |
| Decatur, IL | $1,100 – $6,200 | $3,150 |
| Kankakee, IL | $1,150 – $6,300 | $3,150 |
| Peoria, IL | $1,200 – $6,600 | $3,300 |
| Rockford, IL | $1,250 – $7,000 | $3,500 |
| Springfield, IL | $1,250 – $7,100 | $3,550 |
| East Central Illinois nonmetropolitan area | $1,100 – $6,200 | $3,100 |
| Northwest Illinois nonmetropolitan area | $1,250 – $6,900 | $3,500 |
| South Illinois nonmetropolitan area | $1,100 – $6,200 | $3,150 |
| West Central Illinois nonmetropolitan area | $1,100 – $6,100 | $3,050 |
Frequently asked
Is $3,700 a fair price for gas tankless water heater installation in Illinois?
Yes. $3,700 is right around what most homeowners in Illinois pay. Anything from $780 to $8,140 is inside the normal range for a licensed plumber; above $8,140 it is worth getting a second quote.
Why do quotes for the same job vary so much?
Gas line size — most tanks run on a 1/2-inch line and tankless units often need 3/4-inch, which can add $500–$1,500. Venting: condensing units use cheaper PVC venting than non-condensing stainless. Company overhead matters too: a large company with trucks, dispatchers and a warranty department charges more than a one-person shop, and both can be honest prices.
When should I get a second quote?
Any time a quote lands above $8,140, or when the contractor cannot break it into parts, labor and fees. Ask for the itemized version, ask what would change the price, and confirm licensing and insurance. You can also paste the quote into the free QuoteJury checker for an instant second opinion.
Other plumbing jobs in Illinois
- Gas water heater replacement (40–50 gallon tank)
- Electric water heater replacement (40–50 gallon tank)
- Garbage disposal replacement
- Kitchen faucet replacement
- Toilet replacement
- Running or leaking toilet repair
- Clogged drain cleaning
- Sewer line camera inspection
- Sewer line hydro jetting
- Sump pump replacement
- Water pressure regulator (PRV) replacement
- Main water shutoff valve replacement
- Leaking pipe repair
- Water heater expansion tank installation
- Plumber service call and hourly rate
Gas tankless water heater installation in other states
United States (national) · Alabama · Alaska · Arizona · Arkansas · California · Colorado · Connecticut · Delaware · District of Columbia · Florida · Georgia · Hawaii · Idaho · Indiana · Iowa · Kansas · Kentucky · Louisiana · Maine · Maryland · Massachusetts · Michigan · Minnesota · Mississippi · Missouri · Montana · Nebraska · Nevada · New Hampshire · New Jersey · New Mexico · New York · North Carolina · North Dakota · Ohio · Oklahoma · Oregon · Pennsylvania · Rhode Island · South Carolina · South Dakota · Tennessee · Texas · Utah · Vermont · Virginia · Washington · West Virginia · Wisconsin · Wyoming
Sources
- HomeGuide (2026): $2,100–$5,600 nationally
- Fixr (2025): $2,500–$4,500 nationally
- Angi (2026): $1,400–$3,900 nationally
- Forbes Home (2025): $1,000–$3,500 nationally
- U.S. Bureau of Labor Statistics, Occupational Employment and Wage Statistics, May 2025 — median hourly wages by state and metro area
About these numbers. Ranges are typical market rates for a licensed, insured contractor, blended from published U.S. cost guides and adjusted with U.S. Bureau of Labor Statistics wage data (OEWS, May 2025) for each state and metro area. They are estimates, not a bid, appraisal or inspection. Real prices move with parts, access, permits and code requirements. The quote checker is AI-powered and labeled as such.