Tank vs. Tankless Water Heaters


It seems like there's still no clear winner on the tank vs. tankless debate. While I've lived with my tankless for 2.5 years now, love it and am a strong advocate from a convenience perspective, the questions regarding cost effectiveness, newer and more efficient tank options, and electric vs. gas persist.

According to the U.S. Department of Energy (via Finehomebuilding.com), water heaters consume 14% to 25% of a home’s annual energy use so ensuring yours is efficient should be of high priority.

FineHomeBuilding.com has a fairly comprehensive article outlining the pros and cons of tanks vs. tankless among some of the more popular manufacturers. They also cover a broad range of issues including proper sizing, efficiency, and an overview of how they work.

Below, are the pros and cons of each tank and tankless water heater (via FineHomebuilding.com). See the full article for more information:



  • Lowest up-front costs
  • Easiest installation and replacement
  • Some models don’t require electricity to operate
  • Uses a wide variety of available fuels
  • Can be located anywhere in a home
  • Works well with recirculating systems


  • Standby heat loss
  • Can run out of hot water
  • Tanks are large and heavy
  • Higher life-cycle costs
  • Temperature control might not be precise



  • Lower life-cycle costs
  • Endless hot water
  • Runs only when needed, offering the potential to save energy
  • Accurate temperature control
  • Small and spacesaving; typically wall-hung


  • Higher up-front costs
  • Complicated installation; larger fuel lines often required
  • Electricity required for most models to operate
  • Untreated water can lead to scaling and reduce or halt flow
  • Can suffer freeze damage if improperly installed
  • Minimum hot-water flow required
  • Recirculation is more difficult, with potential to compromise warranty

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