what to look for in a tankless water heater The right tankless water heater can be a game-changer in your home. They offer more energy-efficiency, hot showers for as long as you want them and even more space where your tank-style water heater used to be. However, you want to make sure that you make the right decision about the specific model that you choose, or you may run into problems with your tankless water heater down the road. Here are some things to consider when you’re choosing a tankless water heater.

Tankless Water Heater Size

This is the most essential part of choosing a tankless water heater. Many people choose undersized tankless water heaters, and they don’t realize that they will not be able to run all of the fixtures that they want to at the same time.

Tankless water heaters have a size rating in gallons per minute (GPM). The typical tankless water heater achieves somewhere between 2-5 gallons per minute. If you ask for more hot water than this, you’ll notice a drop in temperature in the water your heater is delivering because it simply cannot keep up with the pace.

To size your tankless water heater correctly, you need to add up the gallon per minute of each fixture that you want to use. So, say you want to be able to run the shower, a sink, and the dishwasher at the same time. You find out the GPM of those fixtures, add them up, and choose a tankless water heater that matches or exceeds that number.

Fuel Source

If you have gas service at your home, you have the choice between an electric or gas tankless heater. If you had a gas heater before, you may be surprised to find that they need a larger gas line than your old tank. That’s because even though they use less fuel overall, they use more fuel in shorter spurts. So, you may be in for a slightly more expensive installation if you choose gas.

An electric tankless heater can use less energy than a gas-powered version because it doesn’t run a pilot light. However, depending on your local utility costs, it may cost more to run an electric version. That’s something to look into and assess to minimize your costs.

Design and Durability

You also want to choose a tankless water heater that is well designed so that it will work well and last as long as possible, to minimize your repair costs and maximize your investment. Certain brands have better reputations than others, and certain models stand out from the crowd too.


Ideally, your tankless water heater will run for years without any issue, but it’s not always a guarantee. When your water heater decides to take a vacation, it can help to have a warranty that covers all parts of the issue, including equipment and labor.

Tankless water heaters tend to have a lot of specialized parts, so when they break down, you can’t always get the parts you need to fix it from a regular hardware store. Some warranty programs cover the replacement of parts, but might take days, or even weeks to ship it!

One of the best ways to avoid this issue is to buy your water heater from a service specialist. For example, we are Navien Service Specialists. That means we carry the necessary parts to repair a variety of Navien tankless water heaters on short notice, without shipping additional parts (among other things.)

No matter which brand you choose, it’s worth looking at the fine print to understand exactly what your warranty does and doesn’t cover, so there won’t be any surprises down the road.

Talk to a Plumber You Can Trust

Talking to your plumber about which models have the best reputation is a good idea. As they maintain and repair them, your plumbers get a sense for how well a unit will perform much better than someone reviewing the unit online, who only knows how the tankless water heater works in their specific home.

The professionals can also let you know if there is something unique that you should be looking for in a tankless water heater to fulfill your specific needs. And if you’re looking for a tankless water heater specialist near Tracy, CA, we’re always happy to help.