What It Is
A water heater without a storage tank which uses electricity or gas to heat water as it flows through the supply pipes.
How It Works
The instant the water valve senses flow, it signals the control unit, which opens the gas valve and ignites the burner. Water heats up as it passes through the copper tubes of the heat exchanger. The control unit also adjusts the burner and flow rate to ensure a constant exit temperature.
Where It’s Useful
Summer houses: Saves times when winterizing because there’s no tank to drain.
Additions: Does away with the need to upgrade existing systems.
Households with big tubs: If a tub exceeds the capacity of the storage tank, hot water could run out.
Under sinks: Samll point-of-use units eliminate the wait for hot water.
Small houses: Compact designs fit where no storage tank could.
What It Costs
$500 to $1500 depending on heating capacity and special features.