Water heater installation cost: 40 and 50 gallon gas tanks and tankless, by state
A 50 gallon gas tank heater: about $2,000 to $2,450, typically $2,200. That's a new gas water heater with the old one taken out, plus the contractor's overhead, profit and sales tax. Moving the heater, new gas or vent lines, an expansion tank and permits are extra.
Anthony Hicks30+ years in construction. Updated November 5, 2026.
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What it costs
| Job | Cost |
|---|---|
| A 40 gallon gas tank heater | $1,800 to $2,200 |
| A 50 gallon gas tank heater | $2,000 to $2,450 |
| A gas tankless heater | $1,950 to $2,600 |
Totals include the contractor's overhead and profit (20%) and the state's average sales tax. Prices as of November 2026.
What’s in these numbers
Each total is a typical job, priced the way a contractor’s estimate is priced:
- A new gas water heater of the type shown, set and connected, with the old heater taken out. The tank heaters are 9 year models; the tankless heater delivers about 4 to 5 gallons a minute.
- Overhead and profit: 20%, the standard markup on a contractor’s estimate.
- Sales tax on the materials, at the state’s average rate.
Not in them: moving the heater, a new gas line or vent, changes to fit a tankless heater where a tank was, an expansion tank, a drain pan, seismic straps, and permits.
Tank or tankless
| Tank | Tankless | |
|---|---|---|
| How it works | Keeps a tank of water hot | Heats water as it flows |
| Sized by | Gallons, and how much hot water it gives in the first hour | Gallons a minute at the temperature rise you need |
| Runs out | When the tank’s hot water is used up | Not while the flow stays within its rating |
A tank heater’s first hour rating, printed on its label, is how much hot water it delivers in the busiest hour starting full. A tankless heater’s rating is its flow in gallons a minute, which falls as the incoming water gets colder.
What moves the price
- Type. Tankless heaters and larger tanks cost more than a 40 gallon tank.
- Fuel. Gas, electric and heat pump heaters are priced differently.
- Venting and gas. A gas tankless heater can need a different vent and a larger gas line than the tank it replaces; its instructions set them.
- Location. Attics, closets and tight spaces take longer than a garage or basement.
- Where you live. Pick your state in the box above.
Common questions
How much does it cost to replace a water heater?
About $1,800 to $2,200 for a 40 gallon gas tank with the old one taken out, typically $1,950.
How much is a 50 gallon water heater installed?
About $2,000 to $2,450 for a 50 gallon gas tank, typically $2,200.
How much is a tankless water heater installed?
About $1,950 to $2,600 for a gas tankless heater where the gas and vent already suit it. The tankless water heater installation cost guide prices electric and larger gas models too.
The old water heater leaked. What else is there?
A leaking tank can soak the floor, walls and anything stored nearby. The water damage restoration guide covers drying out and what comes out.