Ask Focus on Energy

When you buy a water heater, there are many things to consider.

There are several type of water heaters currently available. When purchasing a new water heater, you should consider its size and capacity to meet your needs; its fuel type, and the cost and availability of that fuel in Wisconsin; and its estimated annual operating costs in comparison to other models.

Tank-type (aka storage) water heaters are the most common type of water heater in the US. They store hot water in an insulated tank until it's needed.

• Pros: Low maintenance in most of Wisconsin, can provide a lot of hot water for a short period of time, most units are self cleaning and require little or no maintenance
• Cons: Heat (Stand-by) loss through tank can be substantial, takes up significant amount of area, may run out of hot water when filling large tubs or during longer hot water events

Tankless water heaters have been common in Europe and Asia since the late 1940's and have emerged in the US market in the last several years. These units heat water as needed rather than storing it in a tank where the water suffers stand-by losses as the water cools and must be re-heated.

• Pros: No stand-by losses, provides moderate amount of hot water over a long period of time (indefinitely), takes up less area
• Cons: If not sized correctly, may not provide hot water to multiple fixtures at one time, requires regular maintenance

While the purchase price of a storage water heater will most likely be lower than a tankless unit, the tankless unit will provide a lower operating cost IF it is sized correctly. On average, a natural gas tankless water heater will save about $1,100 over the lifetime of a water heater, compared to a natural gas storage water heater.

Published Thursday, April 16, 2009