Both gas and electric tankless water heaters are energy efficient. Electric heaters require more amperage than most houses supply and they will only run one fixture at a time. Gas tankless heaters will supply two fixtures at a time, but they usually require a larger gas line, new venting and a modified electrical outlet when converting from a tank type heater.

Advantages:

• Only use power to heat water when there is flow
• Provide continuous hot water for as long as needed
  
  

• About three times the price of standard tank type heaters
• Produce a finite volume of hot water per minute.
• Supply a limited number of fixtures