Why don't more people use tankless water heaters?

Author: Ismael Zemlak  |  Last update: Wednesday, June 24, 2026

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!

Why avoid a tankless water heater?

Additional Installation Costs

Tankless water heaters are much more complex than traditional hot water tanks. As a result, they require professional installation. If you're switching from a hot water tank to a tankless unit, you will likely need your gas lines rerouted, as well as a larger gas supply line.

What is the downfall of a tankless water heater?

Smaller heaters can't supply multiple hot water applications at once. Need for multiple units. Some tankless hot water heaters service an entire home, but the flow rate may limit effectiveness in large, busy households. It may be necessary to buy smaller water heaters for each hot water tap.

Why doesn't everyone use tankless water heaters?

They are hard to service. If you get an off brand or brand without a supplier that carries parts they are expensive and time consuming to repair. They require more maintenance. If you lose power you lose hot water.

What are the disadvantages of a tankless water heater?

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 ...

3 Things They Don’t Tell You About Tankless

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

Absolutely! In fact, tankless water heaters are becoming the standard for new home construction because of the energy efficiency.

Is it worth switching to a tankless water heater?

Switching to a tankless water heater can help you save on your energy costs, with potential savings of up to 50%, according to the U.S. Department of Energy. Additionally, tankless water heaters are reported to be 24% to 34% more energy efficient than storage tank water heaters by the same source.

Can you replace a 50 gallon water heater with a tankless water heater?

A 50-gallon water heater should be replaced with a tankless system with a 10 GPM flow rate just to be safe. Selecting the right flow rate ensures you won't experience cold showers or excessive energy costs. Proper sizing optimizes performance, providing hot water on demand without unnecessary waste.

What is the lifespan of a tankless water heater?

Tankless water heaters usually last for around 15-20 years before they need to be replaced, but they may need replacing sooner if they start to break down or lose efficiency. Some common signs your tankless water heater needs to be replaced include: Low water pressure. Water doesn't get hot.

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

The federal tax credit for tankless water heaters in 2024 is an excellent opportunity for homeowners to save money while investing in energy-efficient water heating solutions. This tax credit is effective from January 1, 2023, to December 31, 2032.

What is not a benefit of a tankless water heater?

A tankless water heater cannot provide hot water faster than its ability to heat the water. While a tank unit can provide hot water for multiple uses at once, a tankless unit might not be able to support simultaneous usage, such as washing dishes, taking a shower and running a washing machine all at once.

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.

What's the best hot water heater to buy?

5 Water Heaters You Can Count on, According to Testing
  • Best Overall. A.O. Smith Signature 900 Smart Electric Water Heater With Hybrid Heat Pump. Read more.
  • Best Value. Rheem 50 Gallon Natural Gas Water Heater. Read more.
  • Best Tankless. A.O. Smith Signature Series Tankless Water Heater with Scale Prevention. Read more.

Where should tankless water heater not be installed?

Keep your water heater away from outside elements

If your tankless heater is exposed to extremes weather conditions, it will run a greater risk of premature failure. So, make sure your appliance is away from doors and windows, and never installed in the garage or basement.

Are tankless water heaters the future?

Most models last more than twenty years, as opposed to the typical 10 to 15-year life expectancy of a storage-tank water heater. Given the many advantages offered by going tankless, it's easy to see why tankless water heaters are the future of water heating.

Which is better, a hot water heater or a tankless?

Reliability & Maintenance

tank water heater, the tankless variety tends to be more reliable and require less maintenance. Water heaters with a storage tank have more moving parts than tankless models, so they tend to need more frequent maintenance or repair.

What are the downsides of tankless water heaters?

Cons:
  • The upfront cost is higher than tank storage— but tankless water heaters last much longer, so you even out in the long run.
  • They require more maintenance than tank storage— but this is typically just an annual flush to remove any built-up sediment.
  • Areas with hard water can lessen their lifespan.

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.

Should I replace old water heater with tankless?

Tankless Water Heaters Last Longer — On average, tankless water heaters last longer than tank-type heaters. Most tank-type water heaters have a life span of 10-15 years. The average life expectancy of a tankless heater is more than 20 years. Therefore, there are substantial long-term savings with a tankless unit.

What is the average cost to install a tankless water heater?

[2025 Update] The typical range for tankless heater installation is between $5,400 and $7,400, averaging out to around $6,400 (including the water heater, warranty and tune ups).

What size tankless water heater do I need for a 3 bathroom house?

Proper sizing is important prior to select and installing a tankless, but in general the average rules for sizing the correct water heater for a household are roughly: 3.5 GPM for 1-2 fixtures simultaneously. 5 GPM for 2-3 fixtures simultaneously. 7 GPM for 3-4 fixtures simultaneously.

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.

Do tankless water heaters increase the electric bill?

Because tankless water heaters only consume energy when you need hot water, they're more energy efficient, saving you money on water and energy bills.

Does Costco sell tankless water heaters?

And to keep the hot water flowing, we offer a variety of high-performance water heaters, including electric water heaters, energy-saving tankless water heaters, and the latest smart water heaters. Costco carries a variety of lighting that's perfect for your kitchen, bathroom, dining room, and outdoor living areas.

How much does it cost to install a tankless water heater from Home Depot?

The cost of a tankless water heater at Home Depot can vary depending on the type and features you choose. Generally, electric tankless water heaters have a lower upfront cost, ranging from $200 to $700, while gas-powered tankless water heaters can cost between $500 and $1,500 or more.

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