Tankless water heaters provide hot water on demand
Tankless water heater
To explain the benefits of a tankless water heater, Andy Jasper uses having a house full of guests during the holidays as an example of what a tankless water heater can do that a conventional tank heater cannot.
“You can get 15 people to take back-to-back showers so they can all go to church or out to dinner and nobody would get a cold shower,” said Jasper, the branch manager of Village Plumbing in Indianapolis' Broad Ripple Village.
While a conventional storage tank water heater requires the use of fuel to maintain hot water temperature, even when the water is not in use, a tankless water heater is able to provide an endless stream of hot water and occupies a minimal amount of space.
“In a storage tank, when you’re not using it, the water cools down and the burner has to fire back up again to reheat it, said Steve Morin of Michael Beltrami & Steve Morin Plumbers in Carmel, Ind. “In a tankless water heater, it’s instantaneous. The second you turn the faucet on, it runs through the heat exchanger and fires it. You have a higher efficiency rating. You’re saving money on fuel. It’s a continuous stream of hot water on demand when you need it, unlike a regular storage tank water heater that will run out.”
The U.S. Department of Energy estimates gas-fired tankless heaters can save the average U.S. family 30 percent off their water heating expenses — an average of more than $100 per year — over their traditional counterparts.
“Electric tankless water heaters are also available to homeowners,” Jasper said. “But with our cold incoming water temperatures we have in central Indiana, they don’t seem to be as effective. They use a lot of power … so typically, you have to upgrade your electrical service to even accommodate one.”
There are a variety of models available, but tankless systems typically cost about three times more than a conventional system — between $2,500 and $5,000. While the initial cost is higher, a tankless unit should last 20 years — about twice as long as a tank unit — in addition to the energy savings, additional space and the absence of a tank that could leak.
Tankless heaters also require minimal maintenance. Morin recommends having a tankless system flushed out every year or two, depending on the hardness of your water. A flushing by a qualified plumber costs between $150-$200.
There are some limits to tankless water heaters. Because the unit only provides water it can heat, it’s important for homeowners to manage their water use. For example, if two people are taking a shower at the same time, and the dishwasher is being used, not enough water can be heated at once, so the system will limit the amount it will produce.
“With a tank, you can push all that hot water as fast as you can use it through as many faucets as you want until the hot water is exhausted,” Jasper explained. “A tankless water heater will only let you use as much water as it can heat at any one time.”
Tankless units require more gas or electricity to quickly heat the water, so it’s important only a qualified, licensed plumber install them. Most every home can be equipped with a tankless heater, though some homes will require modifications to accommodate a venting flue. Larger homes will sometimes need more than one unit. Tankless units can also be easily repaired, compared to storage units. Fewer tanks end up rusting in a landfill as a result.
“If a standard tank leaks, you have to throw it out and start over,” Jasper said. “Tankless are more like a furnace. If a part fails, you can change it. You don’t have to start over. Everything in it can be replaced.”
Editor’s note: This article was originally published on February 12, 2011.