There are 2 different kinds of tank water heaters: Conventional gas water heaters and Heat Pump water heaters.
Conventional Water Heating
Conventional storage water heater fuel sources include natural gas, propane, fuel oil, and electricity. All conventional water heaters store hot water 24 hours per day in a storage tank, typically ranging in volume from 20 to 120 gallons.
To minimize stand-by losses you should consider water heaters that offer higher levels of tank insulations. Often the lowest-priced storage water heater may be the most expensive to operate and maintain over its lifetime.
There will always be hot water. Endless hot water - for bathing, cooking, dishes, laundry, and all the other countless ways hot water enriches our lives. We carry a wide variety of gas tank water heaters. They are often the lowest installed cost choice for replacing an existing system.