Water heating is most likely the second-largest energy guzzler in your home—after heating and cooling, of course. So any change you make to your water heating habits is going to save you some money each month. When it comes time to replace a hot water heater, you might consider going for a tankless option.
What is a tankless water heater?
When you think of a water heater, you probably picture a big, cylindrical tank that sits in your garage or tucked away in a closet. But a tankless water heater takes up very little room. It heats water on demand, so there’s no need for a water storage tank. And since it doesn’t have to constantly keep a tank of water hot, there’s no standby energy loss with a tankless option.
How do they work?
There are two types of tankless water heaters, gas and electric. When you turn on the hot water, cold water goes through a pipe and into the water heater. From there, a gas burner or electric element heats the water and then sends it through the pipes in your house so you can use it. It can do this constantly while you have the hot water turned on, which is why there’s no need for a storage tank.
What size do you need?
Most tankless water heaters can supply hot water at a rate of 2 to 8 gallons per minute. The lower the gallons per minute, the less hot water is available at a given time. A tankless water heater that uses 2-4 gpm could be stretched to the max if hot water is needed in more than one area. For example, if you’re taking a shower at the same time the dishwasher is running, there may not be enough hot water to go around. But a smaller model is probably manageable if you live by yourself or with one other person. You can also install low flow fixtures to lower your overall flow rate.
Installing a tankless water heater with a higher gpm means you’ll be able to run more things at once. For most households, a tankless water heater that provides 5-8 gpm is sufficient for all water heating needs.
However, if you have a large household or big family, your home might be best suited for more than one tankless water heater.
How much can you save?
According to ENERGY STAR, a tankless water heater certified with its logo could save the average family about $100 a year. However, how much you save depends on how much water you use. A home that uses less than 41 gallons of water a day will save about 24% to 34% according to the U.S. Department of Energy. Households that use 86 gallons per day would find about 8% to 14% savings. Those with multiple water heaters get the most energy savings at 27% to 50%.
In addition, you’ll see some savings thanks to the lifespan of tankless heaters. They typically last about 20 years, which is double the lifespan of many traditional storage tank heaters.
What are the cons?
It will cost you more to purchase and install a tankless water heater than it would a storage tank model. The tankless variety are a little more expensive up front, and it’s best to hire a professional to install the equipment. There are several factors that have to be taken into consideration when installing a tankless water heater including building code requirements, safety, fuel type and location.