Tankless water heaters heat water only when in use, providing an endless supply with no standby heat loss – they are more compact and lightweight. Tank water heaters pre-heat and store water in a tank (typically 6-10 gallons), have a limited supply and require recovery time after hot water runs out, with standby heat loss – they are heavier and bulkier.
When you open a hot water tap, the flow sensor detects water movement and automatically opens the gas valve and ignites the burner. Water is rapidly heated as it passes through the high-efficiency heat exchanger – taking only about 3 seconds from inlet to outlet. The burner shuts off automatically when the tap is closed.