Tankless water heaters take up much less space than a conventional water heater because there is no longer a requirement to store water for it to be heated. The tankless system connects directly to the plumbing of the home. Water cycles through the unit, providing hot water on-demand. That makes it one of the most convenient options available today for homes that are in higher demand of hot water.
Provides immediate, unlimited hot water when used at directed
Can be installed in very small areas
Energy efficient (may even qualify for a tax credit)
When maintained properly, can have a longer life then a conventional water heater
Higher initial cost for the unit (softener is recommended)
Can have inconsistent temps/pressures depending on how many fixtures you are running at one time
Annual maintenance needs to be done to descale the heat exchanger