To Tankless or Not to Tankless?


That Is the Question on Bob Vila's Blog

When considering the replacement of a traditional hot water heater with a tankless water heater, questions abound: What size unit is best suited for my home? Do I have the right fuel type? Will rebates truly help offset the higher upfront cost of installation? How do ongoing operating costs affect the estimated savings over tanks?

After weighing the pros and cons of replacing her water tank with another or taking the tankless plunge, Gale King addressed those recurring inquiries and more in a recent article on

“A traditional water heater continuously heats water in the tank regardless of whether it is being used. By comparison, the newer tankless designs heat water only when there is demand for it.  Less stored water to heat…less cost,” King explains.

Ultimately, King decided on a Rinnai Tankless Water Heater after learning the following: 

  • Energy savings accumulate over the lifetime of the tankless unit, usually much longer than their electric water heaters
  • Tankless unit selection is based on total number of appliances and fixtures
  • Tankless rebates maximize savings on upfront cost
  • Gallons-Per-Minute is calculated by factoring how many hot water sources are likely to be in use simultaneously
  • Rinnai tankless water heaters use natural gas or propane to heat water to provide continuous hot water, not electricity (except to operate)
  • More northerly climes have colder water, affecting speed and rate of hot water

“In general, a tankless hot water heater will cost you more upfront—the average between $800 to $1,150 (plus installation) compared to traditional tank water heaters at $450-$750 (plus installation),” King noted on her research findings.

According to the U.S. Department of Energy, tankless water heaters can be 24% to 34% more efficient than a traditional tank-style water heater depending on a home's daily hot-water demand.

CORRECTION: The blog post originally cited the following statistic: "The estimated operating costs for tankless models can be as much as 24% to 34% less, according to the Air Conditioning, Heating, and Refrigeration Institute (AHRI)." This finding should have been credited to U.S. Department of Energy’s Energy Efficiency & Renewable Energy website, not AHRI. We apologize for any confusion this may have caused.