Tank vs. Tankless

Here is what I know about conventional gas-powered tank-type and tankless water heaters.

Tank-type water heater stores hot water inside the metal tank and it supplies the fixture no matter what the water flow is, while tankless has a minimum required rate(from 0.4 gallons per minute, up).

Tankless units do not have the stand-by heat loss while storage tank has. When the tank-type unit does not operate, energy is lost through the walls of the heater.

Tankless can provide unlimited quantities of hot water, while with the other you are limited, especially if the unit is undersized or when you have overnight visitors.

When the water flow rate fluctuates, tank-type heater may not supply hot water at constant temperature, while tankless, thanks to the modulating burner, can.

Tankless unit requires less physical space to install and most of the time it hangs on the wall.

Electric tankless vs. tank-type requires an upgrade of the electric service (panel, wire size).

Tankless are more advanced and the energy efficiency is most of the time higher.

Tankless heaters last longer, warranty is also longer, but are more expensive, including the installation costs.

Tank-type uses elements that most of the time end on the landfill, while the on-demand units uses elements which are easy to replace.