Tankless Water Heaters

Tankless water heaters, also known as "on-demand" water heaters, provide hot water instantly without the need for a storage tank. They are more energy efficient since they don't have standby energy losses like traditional storage water heaters. Here you'll learn how they work, if they're suitable for your home, and what to consider when choosing a model. Check out the Energy Saver 101: Water Heating infographic and our #AskEnergySaver discussion on water heating for more information.

HOW THEY WORK

Tankless water heaters heat water directly when you turn on a hot water tap. Cold water enters the unit and is quickly heated by a gas burner or electric element, delivering a constant supply of hot water. Unlike storage water heaters, you don't have to wait for a tank to fill up. However, the flow rate of a tankless water heater is limited.

Typically, tankless water heaters provide hot water at a rate of 2–5 gallons per minute. Gas-fired models have higher flow rates than electric ones. In large households with simultaneous multiple uses, a single tankless water heater might not supply enough hot water. Installing multiple units in parallel or separate ones for specific appliances can solve this issue.

ADVANTAGES AND DISADVANTAGES

For homes using 41 gallons or less of hot water daily, tankless water heaters can be 24%–34% more energy efficient than storage tank water heaters. They can save 8%–14% more energy for homes with high hot water usage, around 86 gallons per day. Installing a tankless water heater at each hot water outlet can increase energy savings to 27%–50%. ENERGY STAR estimates that families can save $100 or more per year with an ENERGY STAR qualified tankless water heater.

Although tankless water heaters have a higher upfront cost, they typically last longer and have lower operating and energy costs compared to storage water heaters. Most tankless models have a lifespan of over 20 years, and their easily replaceable parts can extend their life even further. In contrast, storage water heaters last 10–15 years.

Proper installation and maintenance are essential for optimizing energy efficiency. Hiring a qualified plumbing and heating contractor is recommended, considering factors like fuel type, climate, local codes, and safety. Request written cost estimates, references, and check the company's credibility. If you choose to install it yourself, consult the manufacturer's instructions and local installation codes.

Regular maintenance is important for the longevity and efficiency of your tankless water heater. Consult your owner's manual for specific recommendations.

SELECTING A TANKLESS WATER HEATER

Consider the following factors when choosing a tankless water heater:

• Size
• Fuel type and availability
• Energy efficiency (energy factor)
• Costs

INSTALLATION AND MAINTENANCE

Proper installation and maintenance including flushing are crucial for optimizing the energy efficiency of your tankless water heater.

Considering factors such as fuel type, climate, local building codes, and safety, it is best to have a qualified plumbing and heating contractor install your tankless water heater. Request written cost estimates, check references, and ensure the company complies with local codes.

If you plan to install the water heater yourself, consult the manufacturer's installation and instruction manuals and contact your local authorities for permits and codes.

Regular maintenance, following the recommendations in your owner's manual, can significantly extend the life of your tankless water heater and maintain its efficiency.