10 Best Tankless Water Heaters 2024 in the United States

You need to have hot water in your house or apartment, so it stands to reason that you need to have a water heater. But when you read the words “water heater,” you’re probably thinking of the large tank of water in the basement of the building that keeps a constant amount of water hot and ready to go at a moment’s notice. That, as it happens, isn’t a necessity. Tank water heaters are energy wasters because they have to keep a large amount of water hot at all times just in case they’re needed. Tankless heaters are a modern, cheaper, and more environmentally-responsible option: they heat water, but only as much as you need and when you need it. If you’re thinking about upgrading to a new water heater model, here are some things you need to know.

Electric: Electric water heaters tie into the power lines you use for other home devices to generate their heating power.

Natural gas: If you have access to natural gas power, you might want to look into a propane heater, which will use the same pipes as your other gas-powered accessories.

Indoor: Indoor water heaters will take the place of the inefficient tank-style water heater that’s currently running in your basement.

Outdoor: As their name suggests, outdoor water heaters are installed outside of the house and then send the hot water in through a pipe system.

Here are some of the things reviewers talk about when reviewing their water heater purchases:

• Ease of installation: Some reviewers opted to go with professional installation, while others decided to go it on their own. The best models are easy to install and get running, provided the installer has the right tools and sufficient amount of technical skill.
• Speed of heating: Since there isn’t a tank of hot water ready to go, it’s important that the heater work quickly—otherwise, what’s the point of buying it? The best models work very quickly, meaning that users spend as little time as possible shivering in a cold shower.
• Heat capacity: Great heaters are able to get water hot—not warm—and keep it at a high temperature.
• Energy efficient: Since tankless heaters are promoted as being environmentally-responsible and economically smart alternatives to the traditional model, it makes sense that reviewers talk about how much (or little) they see in terms of energy savings. The best models make a substantial dent in their owner’s energy use.

• Power source: Before you even start looking for a water heater, save yourself some time by making sure that you know what energy sources are available to you. If you don’t have a natural gas line, there’s no point in wasting your time looking at those models.
• Energy use: Be sure to check out the specifications in the heater’s description—for instance, what kind of stress will it put on your electric system, and will the system be able to handle it?
• Capacity: Even though tankless water heaters work on an as-needed basis (and therefore “running out of hot water” isn’t as much of an issue as it is with tank-based models), they still have their limitations. Be sure to buy a heater that is capable of providing enough hot water for you and everyone else in your household who needs it.
• Controls: Take a few minutes to look at the control system that a prospective heater uses. Is it something that you think you (and anyone else in the house who you want running it) will be able to easily figure out and use?

Rheem: Rheem is one of the most well-established companies in the heating and cooling industry. It was founded in 1925, and has been manufacturing a variety of furnaces, water heaters, and related accessories ever since.

Rinnai: Rinnai is a Japanese heating company that has been in operation since 1920. They produce an array of water heaters, home heating devices, and products for business use.

Eccotemp: Eccotemp is an American manufacturer of tankless water heaters. Founded in 2004, the company has expanded its operation over its decade of existence, and now operates in North America, Europe, and Asia.

Ecosmart: Ecosmart is an American company whose sole focus is producing environmentally-responsible water heating systems.