The 8 Best Tankless Water Heaters to Buy in 2018

Leverage these appliances when you're short on space

Shower head
Maciej Toporowicz, NYC / Getty Images

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Tankless water heaters are a great alternative to traditional heaters that rely on a storage tank. Not only do they save on space, they tend to be more energy efficient and economical over time. For people living in a secluded area with limited space, a tankless heater may even be the only option. Whatever your reasons, it’s worth checking out how a tankless water heater may meet your needs at home.

Tankless water heaters work by warming up cold water as it flows through the unit. Using either gas or electricity, most heaters can warm two to five gallons of water per minute. Gas heaters tend to have a higher flow rate, close to the five gallon mark. Electric heaters can be more energy efficient but may struggle to provide the hot water you need as quickly as other options.

To help you explore your options, here are the best tankless water heaters for you to check out.

  • 01 of 08

    Best Overall Tankless Water Heater: EcoSmart ECO 27

    One of the most important reasons you may be considering a tankless water heater is the potential to save some money. Heating any water takes energy, but tankless heaters that are designed with efficiency in mind will use less energy and save you money. The EcoSmart ECO 27 can reportedly save you up to 50% off your normal water heating costs using a simple and reliable electric design.

    The compact unit is small enough to fit in cramp, tight spaces around the home. A digital control will let you set and refine the temperature in one degree increments to fine tune how hot you want the water to be. On top of energy efficiency, the heater is also reliable with easy-to-replace interior copper and stainless steel components.

  • 02 of 08

    Runner-Up, Best Overall Tankless Water Heater: SioGreen IR260

    For people wanting something more than just a water heater, the SioGreen IR260 will help keep your water clean. Using an infrared quartz element to heat the water, this heater avoids the natural metallic taste other options can produce using metals like copper. This keeps the taste of the water pure while achieving the same temperatures as other options.

    The unit comes with a built in temperature control and maintenance free design. Another benefit of infrared heating is water never comes in contact with the quartz element. Therefore, there is no corrosion that will eventually wear down the inside. This also helps to prevent calcium and limescale build ups so you don’t have to clean the interior of the heater.

  • 03 of 08

    Best Budget Tankless Water Heater: Eccotemp EM-2.5

    Eccotemp Eccotemp 2.5 gal. 2 Year Mini Tank Electric Water Heater
    Courtesy of Home Depot

    Budget tankless water heaters are a great option for people who have small hot water demands. A small space like a condo, apartment, or tiny home can usually be covered by these tankless heaters without any major issues. The Eccotemp EM-2.5 is meant to heat only the water you need in a small space. The only limitation with this option is the flow rate of the water. If you need something faster, other options should catch your attention.

    The EM-2.5 excels at point of use heating, meaning you can place this in areas like under the sink or near the shower to heat water in that location. Buying a couple of these units can provide the same basic coverage as larger heaters while giving you the ability to save energy when you don’t need to heat water throughout the house.

  • 04 of 08

    Runner Up, Best Budget Tankless Water Heater: Bosch Tronic 3000

    The Bosch Tronic 3000 is an even smaller option for point of use water heating that is one of the simplest to set up on this list. A single power cord plugs into any standard wall outlet, then you are ready to go. The design is even small enough to be portable, making it a great option for heating water in mobile homes, boats, and outside kitchens.

    The heater comes in three different sizes ranging from 2.5-7 gallons. The design is compact so you can store it under the sink, in a cabinet, or even on the wall with the included wall bracket. Once you have the heater plugged in, hook up a cold water line and start heating all the water you need for that specific location.

    Continue to 5 of 8 below.
  • 05 of 08

    Best Electric Tankless Water Heater: Stiebel Eltron Tempra 24 Plus

    Electric tankless heaters are extremely common, particularly for their energy efficiency and simple set up. Since no natural gas is required, most units will let you plug into a wall outlet. Unfortunately, the energy efficient design can mean the heater will struggle with higher demands. Not so with the Stiebel Eltron Tempra 24 Plus. With a flow rate of up to 4.68 gallons per minute, this one rivals many gas-powered heaters.

    Along with the higher flow rate, the Tempra 24 Plus also gives you advanced control over the flow and temperature of the water. You can reduce the flow to save more energy or tune the temperature to your exact liking. If you don’t want to bother with the manual controls, you can let the self-regulating thermostat do the work for you.

  • 06 of 08

    Best Gas Tankless Water Heater: Westinghouse 11 GPM

    Westinghouse 11 GPM Ultra Low NOx Natural Gas Condensing High Efficiency Tankless Water Heater
    Courtesy of Home Depot

    If you need a tankless heater that can rival traditional storage heaters, gas-powered is the way to go. Using natural gas, these heaters tend to act more quickly so you don’t have to wait as long for the hot water. The Westinghouse 11 GPM doubles the average flow rate of most tankless heaters with the capability of heating up to 11 gallons per minute. If you want a single tankless heater to handle all of your hot water needs, this one is it.

    The tankless heater installs like traditional water tanks, which means you should use a professional to make sure everything is done correctly. The dual stainless steel design will resist corrosion and the usual wear and tear for a longer life. While you are using gas, the heater is Energy Star certified so you can still save some money with an energy efficient design.

  • 07 of 08

    Best Mini-Tankless Water Heater: Ecosmart POU 3.5

    Mini tankless heaters may be small, but they offer a variety of different uses depending on the type of water heater setup you want. For example, instead of using a single, larger heater, you can get the same results with a few mini heaters positioned throughout the house. The Ecosmart POU 3.5 is small and affordable enough to meet your hot water needs if you use two or three individual units.

    This unit can be installed by yourself following a few simple steps. Mount it to the wall or set it on the floor of a cabinet and hook up the necessary lines. The heater will work at a consistent 3.5 gallons per minute, which should be enough for most common small home or condo spaces.

  • 08 of 08

    Best Portable Tankless Water Heater: Camplux 5L 1.32 GPM Outdoor

    Some tankless water heaters are small enough to be portable to carry around. The Camplux 5L 1.32 GPM Outdoor heater is the perfect option if you want some hot water while out camping or traveling in an RV. The unit can heat 1.32 gallons per minute, which is perfect for small needs outdoors.

    Using natural gas, the heater comes with all the connections you need to hook up a gas tank and cold water supply. There is even a supplied shower hose and head for hot bathing water. A single pair of “D” cell batteries power the onboard thermostat so you can control the temperature right from the heater itself.