Storage tanks
A tank provides stored hot water and a familiar replacement path. Compare capacity, recovery rate, fuel type, energy use, location, pan drainage, and existing connections.
Tankless systems
Tankless equipment heats water as fixtures call for it, but it must meet maximum simultaneous flow. Gas venting, electrical service, water quality, and minimum flow can affect installation.
Compare the whole project
Ask for the installed scope, not only equipment price. Include valves, expansion control, venting, condensate, electrical or gas work, access, maintenance, and warranty.
Think about peak morning demand
List the fixtures that may run at the same time, including showers, laundry, dishwashing, and tubs. A system that works for one fixture may disappoint when several fixtures call together.
Maintenance still matters
Tankless units may need flushing based on water quality and use. Storage tanks also need inspection of valves, sediment, and the anode. Ask what maintenance the proposed unit requires.