The standard water heater, also called a storage tank water heater, has a simple operation to understand. A larger tank stores a supply of water, which gas jets heat until it reaches the desired temperature for use. When a water tap turns on in the house, a pump moves the hot water from the tank to the tap. The water heater must run regularly to keep its water supply heated, both because of the depletion of water as its used and because of standby heat loss (i.e. heat escaping through the tank walls).
This conventional method of water heating has worked for households for decades, but it’s no longer the only method of supplying hot water for residential needs. The tankless water heater is now a popular alternate choice. This type of water heater boasts several advantages for the right household. But how exactly does a water heater with no tank even work? We’ll get into that below.