A water heater is an integral part of every home and likely something you do not think about until it stops working. While gas hot water heaters cost less to run due to the lower cost of natural gas, electric heaters are actually more efficient. This is due to the way that the heaters operate. A gas heater must vent the spent gas, which also takes some of the heat with it. An electric heater uses nearly all the energy it receives converting it into hot water, so you have less waste.