Thinking About Buying a Tankless Water Heater? We Can Help You!

all about tankless water heaters

People don’t generally think about their water heaters until they take a shower one day only to painstakingly discover that the water is cold because someone else has used up all the hot water.

And, the worse part? Waiting for the tank to fill back up so it can heat the water again.

That’s where tankless water heaters come in.

Tankless water heaters, also known as demand or point-of-use water heating, offer unlimited hot water.

Yes, endless hot water!

That’s because these heaters work by using heating elements that are activated by the flow of water ONLY when you need hot water, i.e., when you take a shower.

Tankless units don’t store hot water, that is why there is no storage tank – hence tankless. For this reason, tankless units’ heaters can reduce the standby money losses typically associated with hot water heating while minimizing physical space in your home.

Endless hot water, lower energy bills, and additional storage space are just a few of the wonderful advantages of switching to tankless. But, are there any downsides? And, do you really need to go tankless?

Keep reading to find out.

Tankless Water Heaters: How Do They Work?

Tankless water heaters are impressive pieces of technology. While they are increasing in popularity in the United States, the technology has been around for many years. Only recently, in the last decade or so, have they been technologically advanced enough that they provide an average home with an unlimited supply of hot water at a reduced cost (when compared to traditional hot water tanks).

When you to turn on the water, the water flow then turns on the heat exchanger. The water then heats up to the temperature you’ve pre-selected.

Simply put, cold water gets into the water heater through the cold-water pipe. Then it goes through several heating elements and gets out of the unit through the hot water pipe. The input and output temperature of the water is monitored within the unit by use of sensors.

After heating, the water then travels to your faucets and showers through water pipes. As hot water gets depleted from the water heater, the new cold water enters the tank. That means the water constantly passes through the unit and is not stored.

Tip: If you’re using a point-of-use system, you’ll get hot water right away. If, however, you are using a whole-house unit, there can be some delay because the hot water needs time to travel to the faucet. The U.S. Department of Energy’s website explains this further.

If you are looking to buy a tankless water heater system, then be sure to check out our reviews of the top tankless water heater systems for your home

Types of Tankless Water Heaters

Now that we have a general idea for how a tankless unit works, let’s talk about the different types. As you will learn in this article, not all these units are made the same. There are generally two specific fuel types associated with tankless heaters.

Here is what sets these 2 types apart:

Electric Tankless Hot Water Heaters

The heating elements in electric heaters convert electrical energy into heat. The elements are usually placed in direct contact with the water so that heat is directly transferred into the flow. The electric elements then heat up when the flow of water turns on and stops when the water flow turns off.

Readers who are looking to buy an electric tankless hot water heater should check out our list of the top models on the market in our electric tankless hot water buying guide

Gas Powered Tankless Hot Water Heaters

The heating elements in gas heaters are in the form of heat exchangers that transfer heat from the hot combustion of gases to the water. Because of this combustion process, a gas tankless water heater requires access to an exhaust vent.

Electric or Gas? Is There a 'Better' Option?

For most people, an electric tankless water heater is usually a preferred choice over a gas. Aside from them being cheaper to buy and much less expensive to install, latest advances in technology allow them to accomplish some really neat things such as, meeting high flow rate demands in most climates, have the ability to last longer, come with extended warranties, requiring less maintenance, and are overall better for the environment.

People have also found that the maintenance of an electric heater is usually easier than gas. With electric, the most you will have to do is ensure that the screen filter that prevents large debris from entering the system is free and clear of obstructions. With gas, you’ll need an annual inspection to ensure safe fuel combustion and operation.​

Choosing A Tankless Water Heater - What You Need To Know

These devices are extremely impressive, and while they may be much smaller than their traditional counterparts, don’t let size fool you, these units are sophisticated pieces of technology. 

When choose a tankless unit, you need to know three things:

What utility services are available for your home?

If your home is a hybrid between both gas and electrical service, you can choose whichever tankless heater best suits you and your family’s needs. If your home doesn’t have natural gas, you may need to consider if an electric heater will meet you and your family’s needs.

What are your households water flow requirements?

You will need to estimate how much water you think will be used at the concurrently. For example, if you have a one-person household, you are unlikely to have two showers running at the same time, but maybe you would like to be able to have the capacity to run your dishwasher, your washing machine, all while taking a shower at the same time.

What is the groundwater temperature in your region?

Let us say the average person showers with 105˚F water that means if the water entering your home is 70˚F, your tankless heater will only need to heat the water an additional 35˚.

Tankless Water Heater Options For Your Home

tankless water heater for your home

For people who are considering going tankless in their home, you have 2 options:


A whole-house installation is when a single tankless water heater provides hot water for the entire home. The water heating capacity of electric is based on your home’s electrical system. Most homes in the U.S. typically have electric service in the range of 100-150 amps. Older homes tend to have only 100 amps or lower. Due to this condition, installing electric tankless water heaters will often require an upgrade in the home’s electrical system to 200 amps or more (depending on the capacity of the unit to be installed).


In point-of-use installations, electric heaters are more popular than gas heaters because the electric units’ smaller physical dimensions allow them to fit into small spaces such as the cabinets under your sink.

Also, electric tankless units do not require combustion air and an exhaust vent, and thus can be placed practically anywhere in the home! A homeowner choosing to install heaters at the point-of-use may have several small units located at different locations in the house. However, the total number of units that can be installed is still limited by the home’s electrical system capacity.

Tip: Larger homes may sometimes need more than one unit. Tankless units can be used for both residential and commercial purposes.

Tankless Options For Businesses