Are tankless water heaters gas or electric?

Author: Eunice Hilpert I  |  Last update: Saturday, May 3, 2025

Tankless water heaters heat water instantaneously without the use of a storage tank. When a hot water faucet is turned on, cold water flows through a heat exchanger in the unit, and either a natural gas burner or an electric element heats the water.

Does my tankless water heater use gas or electricity?

Tankless electric heaters use an electric element to heat the water. Tankless gas water heaters use a gas burner.

What is the downside of a tankless water heater?

Before you commit to buying a tankless water heater, the primary drawbacks to know include: Higher upfront costs. Tankless water heaters are, on average, quite a bit more expensive to buy and install than tank water heaters. Access to fuel.

Is it cheaper to run an electric or gas tankless water heater?

Prices to heat will vary from region to region however in almost every case a gas tankless will be considerably cheaper to operate than an electric one.

Can I replace my 40 gallon water heater with a tankless water heater?

You can go with a small tank and a small tankless water heater at the same time. You install this as a single device (1.5 gal per minute) tankless water heater with the output going to the tank and the tank feeding your household. If you need a lot of hot water quickly both water heaters run at the same time.

Gas VS Electric Tankless Water Heaters

Why don't more people use tankless water heaters?

Some people hesitate to decide on a tankless water heater because they can be a slightly higher cost; however, you get significantly more life out of one. A standard water heater tank lasts about 8-12 years. A tankless water heater can last as long as 25 years!

What is the life expectancy of a tankless water heater?

One of the most common questions asked by consumers about tankless water heaters is how long they will last. A tankless water heater can last anywhere from 15 to 20 years with proper maintenance and operation. In comparison, a standard tank water heater normally has a working life of 10 years or less.

How much does your electric bill go up with a tankless water heater?

How Much Electricity Does a Tankless Water Heater Use? Many people wonder if tankless water heaters increase electric bills. The answer is no — tankless water heaters can save money on your monthly electric bill because they're 8%-34% more efficient than storage water heaters.

Why not buy an electric tankless water heater?

In summary, while electric tankless water heaters offer advantages such as energy efficiency, space-saving design, and on-demand hot water, they also come with notable downsides. The initial cost of purchase and installation can be steep, and additional upgrades to plumbing and electrical systems may be required.

What maintenance does a tankless water heater need?

The most complicated and time-consuming tankless water heater maintenance is typically descaling and flushing out the unit. Even with the inline water filter, lime and calcium deposits can build up inside the tankless system. If you have hard water, it's a good idea to descale and flush the unit once a year.

When not to get a tankless water heater?

Electric Tankless Water Heaters

They're less expensive than gas-powered ones but aren't efficient if you run multiple hot water devices. They may struggle to keep up with multiple appliances at the same time.

Is there an IRS tax credit for a tankless water heater?

The federal tax credit for tankless water heaters can lead to significant savings for homeowners. Eligible tankless gas water heaters must have an ENERGY STAR certification and a UEF of greater than 0.95. Homeowners can claim up to $3,200 in tax credits for eligible home improvements in a single year.

Can you take a long hot shower with a tankless water heater?

While a tankless water heater will deliver an unlimited stream of hot water, they struggle to deliver a lot of hot water at one time. So while you might be able to take 100 showers in a row if you have the dishwasher, washing machine, and shower going at the same time you might have problems.

Will a tankless water heater work during a power outage?

Tankless Water Heaters Don't Work During a Power Outage

This is an important point because, if you have a storage water heater, you still have access to one full tank of hot water for critical tasks while the power is out.

What is the difference between a mini tank and a tankless water heater?

Whole-home tankless systems provide continuous hot water throughout the house, ideal for larger families or homes with multiple bathrooms, while mini-tank heaters offer localized hot water for specific areas, perfect for smaller spaces or as supplements to existing systems.

How big of a tankless water heater for a family of four?

But on average, different family sizes require the following sizes of tankless water heaters: Family of 2 — 6-8 GPM. Family of 3 — 7-9 GPM. Family of 4 — 8-10 GPM.

What are the downsides of tankless water heaters?

Tankless water heaters have several drawbacks and disadvantages, including a higher initial cost, limited flow rate, specialized venting requirements, potential need for additional equipment, limited hot water supply, delayed hot water delivery, mineral buildup and maintenance, complexity of installation, dependence on ...

Should I get a gas or electric tankless water heater?

Gas tankless water heaters operate most cost-effectively in areas with high power and hot water demands. In contrast, electric heaters use most cost-effectively in areas with low water demands and energy costs. They also might be better in more rural areas with limited infrastructure.

Why is tankless water heater installation so expensive?

Installing a tankless water heater can require gas line upgrades, electrical modifications, and specialized venting—all of which can increase costs. Professional labor also runs from $500–$1,500 due to complex installation requirements.

Is it better to have a tank or tankless water heater?

Operating Costs & Efficiency

Because tankless water heaters are more efficient, they cost less money to operate. This can save you money in the long run since utility bills are lower than with a tank water heater.

What is the most efficient electric hot water heater?

Heat pump water heaters move heat from one place to another instead of generating heat directly for providing hot water, resulting in high efficiencies and significant cost savings. Solar water heaters use the sun's heat to provide hot water and also save money on energy bills.

Do tankless water heaters need to be flushed every year?

Over time, a tankless water heater may accumulate mineral build up which can erode the walls inside your tank's heating chamber. To properly maintain and clean your tankless water heater, it's important to flush those mineral deposits at least once a year.

Do you ever run out of hot water with a tankless water heater?

You can't run out of hot water with tankless water heaters – unless, of course, the power supply is off or goes out. However, a tankless water heater can have trouble keeping up with demand if too many things require hot water all at once.

Which tankless water heater is best?

7 Best Tankless Water Heaters for Large Homes in 2025
  • Best Overall: Rinnai RU199iN.
  • Best Premium: Navien NPE-240A.
  • Best Gas Option: Rheem RTGH-95DVLN.
  • Best Electric: Stiebel Eltron Tempra 36.
  • Best Value: EcoSmart ECO 36.
  • Best Compact: Takagi T-H3-DV-N.
  • Best Warranty: Noritz NR981-DVC-NG.

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