Tankless Hot Water Systems

The new "rage" is tankless hot water systems - "new" being in the States for the last 20 years. European countries have had these systems for well over 40 years.

Tankless heaters have pros and cons, just like everything else. They can supply an endless supply of hot water, and can save energy. However...

They are limited in the amount of hot water that can be produced at one time and they are more expensive to purchase 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. This problem can be solved by using a specialized pump, which in combination with the tankless unit can get your hot water to you at less than half the time it would take running the faucet full blast.

The tankless water heaters also cause an increase in water wastage since you have to let the water run longer to get your hot water. This problem is also solved when using the specialized pumping system. Water conservation is an important advantage to the pumping system.

Tankless hot water heaters save energy and thus money. Water heating accounts for 20% or more of an average household’s annual energy expenditures. The yearly operating costs for conventional gas or electric storage tank water heaters average $200 or $450, respectively.
Storage tank-type water heaters raise and maintain the water temperature to the temperature setting on the tank (usually between 120° -140° F (49° -60° C). Even if no hot water is drawn from the tank (and cold water enters the tank), the heater will operate periodically to maintain the water temperature.
This is due to "standby losses": the heat conducted and radiated from the walls of the tank—and in gas-fired water heaters—through the flue pipe. These standby losses represent 10% to 20% of a household’s annual water heating costs.

Unlike "conventional" storage tank water heaters, tankless water heaters heat water only as it is used, or on demand. A tankless hot water heater has a heating device that is activated by the flow of water when a hot water valve is opened. Once activated, the heater delivers a constant supply of hot water. The output, however, limits the rate of the heated water flow.

HZG was at a seminar recently, sitting enjoying the silence. Two people next to me were in a discussion - loud enough to be heard so I wasn't eaves-dropping. A new complaint regarding the system came up - and I had never heard it before. Some systems have a "minimum" amount of water flow necessary to turn the system on. This gentleman was having issues with not running a faucet full force, for the heat wouldn't turn on.

Sometimes we learn something when we least expect it...