How Does a Tankless Water Heater Work?

If you’re in the market for a new water heater or looking to replace your old one, you might have come across tankless water heaters. These innovative systems offer a range of benefits, but how exactly do they work, and are they the right choice for your Carbondale home? 

In this blog, we’ll explore the inner workings of tankless water heaters, discuss their advantages over traditional tank units, consider essential factors when buying one, and highlight Heartland Heating, Air, and Plumbing’s expert services for tankless water heater installation, repair, and maintenance. Let’s get started!

Traditional Tank Water Heaters Vs. Tankless Water Heaters

Conventional tank water heaters store and continuously heat a large volume of water in a tank. These heaters use more energy to keep the water hot, even when you’re not using it. While they are prevalent and often more affordable upfront, they can be significantly less energy efficient.

A tankless water heater works by heating water only when you need it, providing hot water on demand. Here’s how a tankless water heater operates:

  1. Cold Water Inlet: When you turn on a hot water tap in your home, cold water from the main water supply enters the tankless water heater.
  2. Flow Sensor: The tankless unit’s flow sensor detects the water flow rate and signals the heating elements or gas burner to activate.
  3. Heating Element or Gas Burner: In an electric tankless water heater, an electric heating element heats the water. In a gas heater, a gas burner ignites and heats a heat exchanger.
  4. Heat Exchanger: As the water flows through the heat exchanger or over the heating element, it is rapidly heated to the desired temperature.
  5. Hot Water Outlet: The now-hot water exits the tankless water heater and flows to your hot water fixtures, such as faucets or showers.
  6. Continuous Hot Water: The tankless water heater continues to provide hot water for as long as you need it, as there is no storage tank to deplete. The process stops when you turn off the hot water tap.

Tankless systems provide an uninterrupted supply of hot water because they heat the water as it flows through the unit. There’s no need to wait for a storage tank to refill, making them a convenient choice for homes with high hot water demand. They are more energy efficient as they don’t constantly heat and reheat a large volume of water, reducing standby heat loss and lowering energy costs.

Benefits of a Tankless Water Heater

Now that you know more about tankless water heaters, let’s call out a few of their biggest benefits:

  • Energy Efficiency: A tankless water heater only heats water when necessary, effectively reducing energy consumption and cutting down your utility bills.
  • Unlimited Hot Water: With a tankless system, you won’t find yourself running out of hot water; it offers a continuous supply to meet your needs.
  • Space-Saving Design: Tankless water heaters are not only energy-efficient but also compact and wall-mounted, allowing you to reclaim valuable space within your home.
  • Extended Lifespan: Unlike traditional tank water heaters that typically wear out after 10 to 15 years, tankless hot water heaters can last up to 20 years or more, provided they receive proper maintenance.
  • Environmental Friendliness: Thanks to their lower energy consumption, tankless heaters significantly reduce your carbon footprint, contributing to more environmentally sustainable living.

What to Consider When Buying a Tankless Water Heater

Before investing in a tankless water heater for your Carbondale or Murphysboro, IL home, here are a few things you need to keep in mind:

Fuel Type

Your choice of fuel type depends on your home’s existing infrastructure and your budget. Electric tankless water heaters are generally more affordable to purchase and install. Meanwhile, a gas tankless water heater is more energy-efficient and can provide a higher flow rate.

Flow Rate

The flow rate of a tankless water heater is measured in gallons per minute (GPM). Make sure you calculate the GPM needed based on your home’s hot water demand, including the number of fixtures you use simultaneously.


Selecting the right size tankless water heater is crucial to ensure it can meet your hot water needs. An undersized gas water heater or electric water heater will struggle to provide adequate hot water, while an oversized unit can lead to wasted energy.

Installation Costs

When it comes to water heater installation costs, they can indeed be on the higher side. Installing a tankless water heater might seem a bit more expensive during the initial purchase, but they often yield long-term cost savings. However, it’s crucial to take into account both the initial tankless water heater cost and the ongoing operating costs to make an informed and financially sound decision for your home.


Tankless water heaters require regular maintenance to ensure optimal performance and longevity. However, preventative care will contribute to an extended equipment lifespan, fewer breakdowns, and improved safety.

Trust Heartland for All Your Tankless Water Heater Services

At Heartland Heating, Air, and Plumbing, we believe that tankless water heaters are worth the investment. Our team of experienced professionals can help you improve your home’s energy efficiency and comfort. We offer a range of water heater services, including:


Our experts will assess your home’s hot water needs and recommend the right tankless water heater for you. We will professionally install a tankless water heater that saves energy and provides you with hot water on demand.


If your new tankless water heater encounters issues, our skilled technicians are just a phone call away. We’ll diagnose and repair any problems to keep your hot water flowing.


Regular maintenance is a must with tankless water heaters. To make it easier for busy homeowners, we created an affordable HVAC maintenance program called the Heart of Your Home Club to save you money and time. When you become a member, we’ll proactively schedule bi-annual service appointments in the spring and fall to clean and check your HVAC system and inspect your water heater’s condition.

You’ll also receive:

  • Priority emergency service
  • A 15% discount on repair parts and labor for plumbing and HVAC
  • No overtime charges Monday through Saturday

Schedule Your Tankless Water Heater Installation Today

Ready to upgrade your old hot water heater tank with a new tankless model or start your new build with a more energy efficient system? Whatever the case may be, Heartland Heating, Air, and Plumbing can take care of your tankless water heater installation with ease.

Our professional plumbing services are trusted by homes and businesses all over Southern Illinois. Contact us today to explore your options.