A tankless water heater works by heating water instantly as it flows through a heat exchanger — there’s no storage tank. When you open a hot-water tap, the unit senses the flow, ignites the burner (gas) or activates the heating elements (electric), and superheats the water during the few seconds it takes to reach your faucet.
How the cycle runs
- You open a hot-water tap
- Flow sensor detects demand
- Burner or heating elements activate
- Cold water passes through the heat exchanger
- Hot water flows out to the faucet — continuous, on-demand
- Unit shuts off when flow stops
See our tankless water heater service for sizing, install, and service.
