The most efficient domestic water heaters include electronic-ignition gas-fired on-demand models. Other factors to consider include air quality ( in terms of combustion gases) and the ozone-depletion impacts associated with refrigerants for heat pumps and blowing agents for storage tank insulation. On-demand water heaters have no standby losses or storage tank insulation concerns, and some models have sealed combustion and no pilot lights.
For more information on Tankless Hot Water Heaters , please go to SoCal Gas
