How Tankless Water Heaters Work

Home / How Tankless Water Heaters Work

Tankless heaters are a very interesting type of water heater. We are going to describe how they work in this article and also outline some differences between tankless heaters and traditional water heaters.

The first thing you need to be aware of in terms of the tankless heater versus the traditional water heater is the difference in size. When we perform a water heater installation, we know this is an important factor for many people. Some people need to very conscious of the size of their water heater depending on the layout of their home.

Tankless heaters are quite a bit smaller than traditional water heaters. Also, the tankless heater does not have a huge vent that comes out of it either. This means that if you want to conserve space, tankless can be a good option for you.

How Tankless Heaters Work

With a traditional water heater, you’re going to be considering the size of the tank. This means that you might need a 75-gallon tank for a house of 6 people, for example. You may need to adjust your mindset when you think about tankless heaters.

For tankless heaters, you’re going to think about the flow rate of the water and not the capacity of the water heater. When we perform a water heater replacement, we sometimes have to educate people about this change in mindset. You’re going to be looking at the Gallons Per Minute (GPM) metric with the tankless option.

You have to calculate with tankless heaters hot many gallons you will require in your home at the same time. You don’t have to worry about how many gallons you’ll use in a day like you do with traditional water heaters. So, figure out how many washers, tubs, sinks, and showers might be in use at one time.

If a kitchen faucet in your home uses 2.5 GPM, your washing machine uses 2.5 GPM, and two showers use a combined 6 GPM, you would need a tankless water heater that can heat 11 GPM. What you have done is to calculate the number of gallons of water per minute all of these items in your home use at once.

“Endless” Hot Water with the Tankless Water Heater

Tankless heaters provide “endless” hot water. The hot water in your faucet or shower can actually run as long as you want it to run! It will never run out. With traditional water heaters, hot water is available only for a certain amount of time. It will eventually “run out”. This is not the case with the tankless option.

It works by sensing water running from somewhere in your house. This could be the tap or the shower, for example. It heats the water as it goes through the system in your house. It is electric, so it can heat the water as long as you require it to be hot.

Water Heater Services & Water Heater Repair in Birmingham AL

We are experts at water heater installation and water heater repair in Birmingham AL. We can help you in any way that you may need us to, including tankless heater service or installation. We take pride in providing amazing customer service and responding quickly to your calls. Contact us today if we can assist you in any way.

Posted in

Our Schedule


Want to book an appointment?

We are usually available for same day services,
call today to check our availability and get scheduled!



Plumbing Professionals
3411 Lorna Lane
Hoover, AL 35216, US
(205) 683-4436


PO Box 360133
Birmingham, AL 35236
(205) 683-4436


3 Office Park Cir Suite #117
Mountain Brook, AL 35223, US
(205) 369-6529


Business Hours
Monday - Friday 7:00 AM to
5:00 PM