Tankless water heaters seem to be all the rage these days, but how do they even work? To some of us who are older, the idea of not having a sitting tank of water in your garage may be completely foreign; how are you supposed to have hot water if it’s not heated up first?

Thanks to huge advancements in technology over the last few decades, tankless water heaters are not only effective, but cost-efficient as well. They require more of an initial investment than a regular hot water heater, but they last longer than traditional water heaters and have a more consistent water temperature to boot. Moreover, hot water appears faster, it takes up less space in your home, and minimizes the flooding risk that is ever-present with tank heaters. And as mentioned, it saves money, too.

How Do They Work?

Instead of having a water tank that is constantly being warmed by a heater, tankless water heaters operate by bringing in water through a pipe and running it by a gas burner or electrical unit that heats the water. Though most tankless water heaters run to the whole house, it’s possible to have one dedicated to just a specific area, such as the master bathroom or dishwasher. They operate quickly; a gas burner can produce up to five gallons of hot water per minute, which means you won’t run the risk of running out of hot water if you have company over. For extra power, you can also install two tankless water heaters to run in tandem with each other.

How Efficient are They?

Tankless water heaters only heat water when it’s needed, as opposed to a tank heater which heats the water and then lets it sit until needed. It’s almost guaranteed to save you money in the long run, but exactly how much money varies from house to house. A home that uses a lot of water, such as 80 gallons or more, for instance, may see savings in the 10% range, while homes that use around 40 gallons daily will save closer to 25-30%. If you want to know how much water your specific home will save, there’s a tool for that.

Factors to Consider When Buying

Water heaters are becoming more common in the United States, which means you’ll have a variety of options at your fingertips if you decide to purchase one (or two) for your home. Before you decide to go tankless shopping, think about your needs first.

  1. Gas or Electric? If you have both running in your house, then you may have the option of choosing an electric or a gas-powered water heater. There are advantages to both, but generally speaking, an electric tankless heater will cost less to install and maintain, but will be outperformed by a gas heater. Gas heaters may also require you to install expensive venting systems to operate, so it’s worth looking at electric systems if you have the option. 
  2. How Much Water Do You Need? This one will require a bit of math to figure out, but in order to find the right water heater for your house, you’ll need to calculate your home’s peak demand flow rate (GPM) and your home’s temperature rise. Here’s a simple guide to determine both. Once you’ve figured this out, you’ll know what type of heater you’ll need. 
  3. Is There a Warranty? A good warranty communicates to you, the buyer, that a company is willing to stand behind their products. The length and width of their warranty is important to consider when choosing your water heater, but it changes depending on the issue covered. Parts may only be warrantied for a few years, but the heat exchanger may be covered for closer to fifteen. Either way, factor in what you’re paying for and be ready to cover some expenses out of pocket as the system ages.