Best Tankless Water Heater: Top 10 Models

One of the most expensive water heaters, the Rheem Performance Platinum, can heat an impressive 9.5 gpm.

It has a long PVC venting capability, so you have more flexibility with its placement.

Customers love the water conserving feature, as well as the energy efficiency. However, this is one of the more expensive tankless water heaters, so it may take longer to begin saving money. Like most tankless water heaters on this list, there are different lengths of warranties for different parts.

The heat exchanger comes with a 12-year warranty, while the rest of the parts have a 5-year warranty. Consider this water heater if you want a reliable and heavy-duty tankless unit for a larger household.

Like most electric tankless water heaters, the EcoSmart heater is far less expensive but offers less gallons per minute of continuous hot water.

You can use this water heater in any climate, but it’s ideal in colder climates. Enjoy this water heater without any stress, thanks to the lifetime warranty.

While it only heats 5.3 gpm, this is enough for many households.

However, because it is electric, it may be more expensive than other units throughout its lifetime due to higher energy costs.

One of the best mid-range options, this expensive electric water heater combines the affordable cost of electric units with the high gallons per minute of a natural gas water heater.

It can heat up to 6 gpm, which is perfect for a small family or a couple. The electronic controls and lack of exhaust venting makes it easy to install and operate.

However, you’ll still want a professional to make sure the heater is installed correctly and safely. Choose this model if you want the largest electric water heater on this list

For a smarter water heater, check out the Stiebel Eltron Tempra Plus tankless water heater. Not only does this electric unit have digital controls, it also uses self-modulating technology to keep consistent hot water. 

If you ever need more hot water than the heater is capable of producing, it will decrease the flow slightly in order to keep your water hot. You’ll never worry about a cold shower again.

It’s a great choice if you want a high-quality electric unit that produces a reasonable amount of hot water for two bathrooms in most climates.

The most expensive tankless water heater on this list combines excellent flow volume with low emissions. 

The Rinnai Ultra Series heater works for both propane or natural gas and provides low NOx emissions for a cleaner alternative. 

The sleek, durable look matches the warranty and build quality. This unit has an easy-to-use digital control panel, which makes it easy to adjust the temperature or turn the heater on and off. 

It’s an excellent choice if you want an efficient and high-volume tankless water heater.

This lightweight unit is inexpensive and offers enough hot water for three faucets, like a bathroom and kitchen.

It’s a very affordable option for a smaller household and perfect for a home that isn’t connected to natural gas. 

The thermostat dial is easy to control and offers you a range of temperatures from 90 to 135 degrees.

While it doesn’t have the best warranty or adjustable settings, it’s perfect for a small cottage or as a second tankless water heater.

If you’re looking for a durable model that balances cost and efficiency, the Takagi T-K4-OS-NG is an excellent choice. This unique model is designed to be installed outdoors only. 

It’s more durable and has built-in venting that isn’t acceptable for indoor installations. This unit features 8 gpm, 190,000 BTUs, and comes at a reasonable price for a natural gas tankless water heater. 

Choose this option if you aren’t able to properly vent an indoor water heater.

Because the Sio Green water heater is the most affordable on the list, it shouldn’t be surprising that it offers the least amount of hot water. It’s best used as a point-of-use water heater, which is meant to supply consistent hot water to only one faucet or shower head. 

It’s perfect for a guesthouse or upstairs bathroom that has trouble getting consistent hot water with good pressure. If you live in particularly cooler climates, this unit will only be suitable for a low-flow sink and not a shower head. 

This heater won’t supply hot water to your entire house, but might be a perfect addition to a house that needs a little boost in hot water.

Similar to the Takagi T-K4, this Rheem tankless water heater is designed for outdoor use. It’s slightly more expensive and offers similar gallons per minute. 

Just like the Takagi outdoor unit, it’s designed to resist freezing temperatures. You can install this water heater outdoors even in areas that experience -30 degree temperatures. 

The additional cost of this outdoor tankless water heater also covers the impressive warranty. Not only are the parts covered under a 5-year warranty, you’ll enjoy a 12-year warranty on the heat exchanger. 

Choose this outdoor model if you want more peace of mind with a longer warranty. Otherwise, the Takagi T-K4 is a more cost-effective option.

In terms of cost-effectiveness, the Westinghouse tankless water heater is the best option on the market. You’ll receive an impressive 11 gpm. It’s covered with an excellent 12-year warranty and has low NOx emissions. 

Many customers experience water pressure and temperature issues. When it works well, it’s the best model on the list, but there are build quality issues with this unit. 

Choose this model if you want the most cost-effective and heavy-duty water heater on the list.