Tankless water heaters heat water when a hot tap opens. They take up less storage space than a conventional tank, but they still have limits and installation requirements.
Benefits and limits
A suitable unit can supply hot water for a long shower without emptying a storage tank. It cannot heat an unlimited number of fixtures at once. Performance depends on flow demand and incoming water temperature, so sizing matters.
The installation may need changes to venting, gas supply, electrical service, condensate handling or water piping. Maintenance requirements vary by model and water conditions. Ask for a complete proposal rather than comparing appliance prices alone.
Match the home
List the fixtures likely to run at the same time and what frustrates you about the current heater. Our water-heater team can discuss whether tankless or another option better fits your household.
Check the home before selecting a unit
A wall-mounted heater frees the floor space occupied by a tank, but it still needs suitable clearances and a practical place for servicing. Ask where the vent will terminate, what fuel or electrical capacity is available, and whether the chosen model needs a condensate drain. Those answers belong in the installation quote, not in an assumption that the new unit can simply replace the old tank’s connections.
Also ask what will happen at peak demand. If several showers or appliances run together, the unit may need to be larger or the household may need to stagger use. A properly sized tankless system can provide continuous hot water at its rated flow; it cannot exceed that flow indefinitely. Our guide to how tankless heaters work explains why.
For a fair comparison, look at the full installation cost and the model’s service requirements as well as the appliance price.