Tankless water heater installation cost
Short answer
Most whole-house tankless installs in 2026 land roughly between $1,400 and $5,600. Electric units are usually at the lower end, around $1,400 to $3,000 installed, while gas units often run $2,100 to $5,600 because of gas line and venting upgrades.
In this guide
A tankless water heater costs more to install than a tank, and the unit itself is often not the biggest part of the bill. What drives the price is how much your home has to change to support it.
The ranges below are based on 2026 national cost guides. Local labor rates, permits and your home's existing setup can move your quote above or below them.
Typical cost by fuel type
| Type | Typical installed cost | Notes |
|---|---|---|
| Electric, whole house | About $1,400 to $3,000 | No venting or gas work, but may need new circuits or a panel upgrade |
| Natural gas or propane | About $2,100 to $5,600 | Higher flow rates, but often needs a larger gas line and new venting |
| Point-of-use (single sink) | Unit alone often a few hundred dollars | Serves one fixture, not the whole house |
Replacing an existing tankless unit with a new one usually costs less than converting from a tank, because the gas line, venting and electrical work are already in place.
Upgrades that raise the price
These are the items that explain why two quotes for the same unit can differ by thousands of dollars.
Larger gas line
Gas tankless heaters draw far more gas at once than a tank. Many homes need the supply line upsized, commonly from 1/2 inch to 3/4 inch. Depending on the distance and access, cost guides put this anywhere from a few hundred dollars to about $2,000.
New venting
A gas tankless heater cannot always use the old tank's vent. Condensing models typically vent through PVC, and non-condensing models need stainless steel vent pipe. Expect the cost to rise if the vent has to run through a roof or a long path.
Electrical work
Electric tankless heaters draw a lot of current and often need one or more dedicated circuits. If your panel does not have the capacity, a panel upgrade can add well over $1,000.
Permits and haul-away
Many cities require a permit for water heater work. Removal and disposal of the old tank may or may not be included in a quote, so ask.
Gas vs electric: which is cheaper overall?
Electric units cost less to install, but whole-house electric tankless heaters can struggle to keep up with several showers at once, especially in cold climates where incoming water is colder. Gas units cost more upfront and deliver higher flow rates. Your utility rates decide which is cheaper to run over time.
Before you choose a size, use our water heater size calculator to estimate the flow rate you need at your area's temperature rise.
How to compare quotes
- Ask what flow rate the proposed unit delivers at your temperature rise, not just its maximum rating.
- Ask whether the quote includes gas line upsizing, venting, electrical work, the permit and removal of the old tank.
- Check that the installer is licensed and that the installation keeps the manufacturer's warranty valid.
Ongoing costs to plan for
You will need to descale a tankless water heater regularly, usually once a year and more often with hard water. You can do it yourself with a small pump kit, or pay a plumber for a service visit. Skipping it shortens the life of the heat exchanger.
Common questions
Is a tankless water heater worth the extra cost?
It can be if you plan to stay in the home for years, since tankless units often last longer than tanks and use less energy. The payback is slower if your install needs a large gas line or panel upgrade.
Can I install a tankless water heater myself?
Gas line, venting and high-amperage electrical work are usually required to be done by licensed trades and often need a permit. A DIY install can also void the manufacturer warranty.
Why is my tankless quote so much higher than the unit price?
Most of the difference is labor and upgrades: a larger gas line, new venting, new electrical circuits and the permit.
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