Water Heaters: Tank vs. Tankless

One question that often arises when we’re meeting with our clients is whether or not they should elect to purchase a tank or tankless water heater(s). There are various opinions regarding which is the better option and to be fair, it’s predicated upon what your personal needs are. In this article, we’ll try to wade through some of the differences between the two and the myths surrounding both.

Traditional storage tank water heaters are the most common type of water heater currently available on the market. As the name suggests, they are large, insulated tanks that hold and heat water. In order to provide hot water when you need it, the tank continually heats the water thereby maintaining a constant temperature. Unfortunately, this occurs even when you don’t necessarily need hot water and this wasted energy is defined as standby heat loss. Tankless water heaters, on the other hand, provide hot water only as needed by utilizing a burner and heat exchanger to heat cold tap water which enters from the inlet pipe for the unit.

Comparative breakdown:

  1. Savings – For homes that use 41 gallons or less of hot water daily, demand water heaters can be 24%–34% more energy efficient than conventional storage tank water heaters. They can be 8%–14% more energy efficient for homes that use a lot of hot water -- around 86 gallons per day. You can achieve even greater energy savings of 27%–50% if you install a demand water heater at each hot water outlet. ENERGY STAR® estimates that a typical family can save $100 or more per year with an ENERGY STAR qualified tankless water heater (www.energy.gov).

  2. Now despite these seemingly large efficiency gains, at the end of this paragraph notice that a typical family only saves $100 or more per year with these units (the more isn’t thousands), what people often neglect to discuss is the fact that typical tankless units cost 3x or more than a traditional storage tank water heater. When you break down the costs over time the delta doesn’t seem significant enough to warrant selecting one or the other solely based on price.

  3. Lifespan – Tankless water heaters typically last 20 years or more in comparison to a traditional storage tank’s lifespan of 10-15 years. The increase in lifespan and higher efficiency ratings of tankless units could be the long-term cost savings that offset their higher purchase price.

  4. Size – Tankless units clearly win in this category as they’re much smaller and even when adding a couple of tankless units for larger households, this still requires less space than a traditional tank. Additionally, tankless units can be installed outside with an anti-freeze kit.

  5. Performance – Tankless units supply nearly limitless hot water. Remember when your wife took two Jacuzzi-style hot baths and then the kids all had bubble baths too? Well with a traditional tank that often meant you were left coming home to a nice lukewarm bath, not necessarily the ideal temperature after a long day’s work. With tankless units you’re no longer subject to these underwhelming bath experiences, instead you become the beneficiary of a system that produces a limitless supply of hot water.

  6. Tankless units provide instant, on-demand hot water, but the caveat here is that if the power goes out, so too does your hot water. With a tank, you can typically squeeze out a couple of hot showers from the remaining hot water left in the tank.

  7. Maintenance and Hidden Costs – Tankless water heaters have a longer lifespan and typically require less maintenance, but they also come with various hidden costs such as the possibility of needing a larger natural gas line to supply the unit with fuel and stainless steel tubing for venting gas and propane units.

  8. Tank Water Heater Maintenance: https://www.youtube.com/watch?v=x2A3ry3kFQ4

  9. Tankless Water Heater Maintenance: https://www.youtube.com/watch?v=znuACzzav_Y

  10. Water Softeners – Water softeners can help reduce the frequency of flushing your units. For more information about these systems, see the links provided below.

  11. https://www.freedrinkingwater.com/whole-house/water-filter-knowledge-base/water-softening-vs-water-filtration.htm

  12. https://www.ecowater.com/home-water-solutions/whole-home-systems/

  13. https://www.thewatersoftener.com/reviewing-best-water-softeners/

Click this Image above for a detailed look into the anatomy and functionality of each unit.

Tank water heaters remain the most utilized type of water heater in the United States, and with the updated IECC requirements, both tank and tankless heaters look to continue to improve upon their efficiency ratings (for more information go here: https://codes.iccsafe.org/public/document/IECC2015/chapter-4-re-residential-energy-efficiency). Ultimately, you as the buyer have to determine what works best for your family.

Sources - All article links, as well as below:

1. “Tankless or Demand-Type Water Heaters.” Department of Energy, www.energy.gov/energysaver/water-heating/tankless-or-demand-type-water-heaters.

2. Bryant, Charles W. “How Tankless Water Heaters Work.” HowStuffWorks, HowStuffWorks, 22 Feb. 2008, home.howstuffworks.com/tankless-water-heater3.htm




5220 Spring Valley Road, Suite 212

Dallas, Texas 75254

Office: 469 333 8880

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