Tankless water heaters, often referred to as instant or instantaneous water heaters, do not instantly heat water. Heating water takes time whether it’s a big tank full, or a long piece of tubing coiled up over a natural gas burner.
Tankless water heaters have pros and cons, just like everything else. They can supply an endless supply of hot water, and can save you energy because, they do not have standby losses like storage type water heaters.
However, they are limited in the amount of hot water that can be produced at one time and they are more expensive to purchase and install than a conventional storage type water heater.
They also make it take longer for you to get your hot water, since they don’t start heating the water until you turn on the faucet. Typically they add 10 to 20 seconds to the time it takes to get hot water to the fixture.
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