How do tankless water heaters work?

I am looking to replace my old water heater and wanted to know some more information about tankless water heaters? How do they work and where can I find them?

The Expert Answer:

Tankless water heaters go by many names, including Combination Boilers, Instantaneous, Continuous Flow, Inline, Flash, or On-Demand, however their benefits to your utility bills are universal. These devices heat the water as it flows through the device, and do not hold a reserve of hot water like traditional water heaters. The only water that remains in a Tankless Water Heater at all times is the water that fills up the heat exchanger coils.

The water savings are instantaneous, as a home no longer needs to keep water at a high temperature at all times. This has the potential to save money for consumers on two fronts: It requires the use of less water in a home, and it also lowers energy use.

The first point seems obvious, however the second point may be tricky. As your hot water heater sits in the basement, it is required to keep water at around 120 degrees Fahrenheit at all times, however the basement will always be at least somewhat colder than the ideal temperature for hot water. As the tank of heated water sits in the cold room, heat escapes from the tank, requiring the hot water heater to work continually at keeping the heat of the water at desired levels. This is akin to keeping a pot of water boiling on the stove all day long, just in case someone wants to make spaghetti. It makes much more sense to heat the water only when you know you'll need it. The analogy has a limit, and that is it will not take nearly as long to get a hot shower going as it will to heat a pot of water to a boil. Tankless water heaters will both save you money on your utility bills, and provide a continuous flow of hot water.

But how does the machine actually work?

The process begins when the hot water tap is turned on. This is the signal for water to start entering the heater. Once the water flow sensor detects the flow of water, the computer automatically ignites the burner. Water then cycles through a coil that is wrapped around the heat exchanger, which will heat the water to the designated temperature. When the tap is turned off the machine will shut down.

There is a lag between the desire for hot water and its production. However the time lost waiting for initial hot water will be overcome by the fact that the supply is limitless, and will not sit around in your basement losing heat for any extended period of time.

When evaluating whether to go Tankless, get an installed price from a qualified professional. You can do that here: find contractor. The installation of a Tankless unit will cost more than swapping out for a new tank because it requires new installation costs to account for the computer and software associated with the Tankless System. For a list of Takagi Tankless Water Heaters: Click Here. Or, to calculate how much a Tankless Hot Water Heater can save you: Click Here.

If you currently have a water heater with a tank, and are not prepared to make the upgrade, you may want to consider a Hot Water Heater Blanket. If, when you place your hand on the Hot Water Heater, you can feel warmth; this means your Hot Water Heater is leaking heat into your basement. A Hot Water Heater Blanket will insulate the heat inside your tank, and prevent your heater from working harder than it needs to, saving you money on electricity.

February 29, 2008 at 5:57 pm :: Comments to date: 1