Tankless Water Heater Cost

Tankless (on-demand) water heaters cost more up front than tank models but last longer and can lower energy bills. HomeGuide puts a whole-house tankless unit at $1,400 to $5,600 installed; Angi's typical range is $1,400 to $3,900.

Cost by fuel type

Source: HomeGuide. Point-of-use units that serve a single sink cost $150 to $250 each before installation.

Installation and labor

HomeGuide puts tankless labor at $600 to $2,500, usually 3 to 10 hours of work, plus $150 to $300 for pipes, connectors and valves and $50 to $200 for permits. Angi's labor range for a tankless replacement is $600 to $1,900.

Upgrades that raise the price

HomeGuide notes that a gas tank's old vent cannot be reused for a tankless unit. Electric tankless units draw a lot of power at once, which is why some homes need a panel upgrade. See replacing a tank with a tankless water heater for the full conversion.

Operating costs and payback

HomeGuide says the extra investment can be recouped in as little as 3 to 7 years, and mentions a federal tax credit for Energy Star certified gas units. According to the IRS, that credit (section 25C) is not allowed for property placed in service after December 31, 2025, so it no longer applies to new installations. Non-condensing units cost about 25% less to install than condensing units but have higher energy bills.

Lifespan

HomeGuide lists 15 to 20 years for tankless units, compared with 8 to 12 years for a tank. Regular descaling helps reach that range; see tankless water heater maintenance cost.

How tankless heaters work

A tankless water heater heats water only when you turn on a hot water tap. Water flows through a heat exchanger warmed by a gas burner or electric elements, so there is no tank of hot water waiting and no standby heat loss.

Gas vs. electric

• Gas tankless units have high output and suit larger households, but they need a properly sized gas line and venting.
• Electric tankless units are simpler to vent but draw a lot of electrical current, which may require panel upgrades. They work best for smaller households or point-of-use applications.
• Condensing gas models extract more heat from exhaust and are more efficient, with PVC venting.

Sizing

Tankless units are sized by flow rate and temperature rise, not gallons. Think about how many showers and appliances might run at the same time, and how cold the incoming water gets in winter.

What affects the price

• Gas line or electrical upgrades.
• Venting type and length.
• Unit capacity and whether it is condensing.
• Mounting location, indoor or outdoor.
• Installing isolation valves for future flushing.

Pros and cons

Tankless heaters provide continuous hot water, take up little space and typically last longer than tanks. They cost more up front, need regular descaling, and can have a short delay before hot water reaches the tap.

Questions to ask

1. What size unit do I need for my peak demand?
2. Will my gas line or electrical panel need upgrading?
3. Does the installation include service valves?

In Texas

Warmer incoming water for much of the year helps tankless units in Texas, but hard water in many cities means regular descaling is important to protect the heat exchanger.

Sizing by flow rate and temperature rise

Tankless heaters are sized by how many gallons per minute (GPM) of hot water they can deliver at a given temperature rise. The temperature rise is the difference between the incoming groundwater temperature and the hot water temperature you want at the tap. Homes in warm climates have warmer incoming water, so the same unit delivers more hot water there than it would in a cold climate.

To size a unit, add up the flow rates of fixtures you might run at the same time. A shower head, a kitchen faucet and a dishwasher together can easily exceed what a small unit delivers. An undersized unit is the main reason people are disappointed with tankless heaters.

Whole-house vs. point-of-use

A whole-house tankless unit serves every fixture. Point-of-use units are small heaters installed near a single fixture, like a remote bathroom or a kitchen far from the main heater. Point-of-use heaters cut the wait for hot water at that fixture and can supplement an existing tank or tankless system, but they do not replace a whole-house heater.

Condensing vs. non-condensing gas units

Condensing tankless heaters capture more heat from exhaust gases, which makes them more efficient. Because the exhaust is cooler, they can vent through plastic pipe, which is often cheaper and easier to route. They produce acidic condensate that must be drained, sometimes through a neutralizer. Non-condensing units cost less up front but need stainless steel venting, which raises installation cost.

Who benefits most from tankless

• Households that run out of hot water with a tank.
• Homes where floor space is tight.
• People planning to stay in the home long enough for energy savings to add up.
• Homes that already have a large gas line and easy venting.

They make less sense where the existing gas line and venting would need major upgrades, or where hot water use is low.

Questions to ask the installer

1. What GPM and temperature rise did you size the unit for?
2. Does my gas line need upsizing, and is that in the quote?
3. Will you install isolation valves for maintenance?
4. Is a recirculation option available if we want faster hot water?
5. What maintenance does the warranty require?

Rebates

Some gas and electric utilities offer rebates on high-efficiency water heaters. Check your utility's website before buying, since some programs require pre-approval.

More on lifespan

Well-maintained tankless heaters usually outlast tank heaters.

Space and clearances

Each model lists required clearances around the unit for service and venting.

Payback without the federal credit

With the federal credit gone for new installs, payback depends on energy savings and any local utility rebate. Ask your utility what it offers before you buy.

Sources

1. HomeGuide: How Much Does a Tankless Water Heater Cost? (Jan 2, 2026)
2. Angi: How Much Does Water Heater Replacement Cost? (updated Jul 20, 2026)
3. IRS: FAQs on the modification of sections 25C and 25D under the One Big Beautiful Bill