How Does a Tankless Water Heater Work? (Answered)

portable electric water heater

A water heater is a daily need in cold-based countries. It makes the water usable by heating it up. Usually, people use conventional tank-based water heating system to heat up the water. But that is not an optimal solution and the number of dissatisfied people using tank-based water heater is increasing day by day.

If you are one of them too, you should get yourself a tankless water heater. Water heating technology has come a long way and some marvelous technology has been invented since then. A tankless water heater heats water as soon as you need it without any necessity of any storage and I am sure you will love it.

A tankless water heater will heat the water as before it goes to the facet or shower you need it, thus eliminating the need for storing heated water in a tank continually, this saves energy. Having a tankless water heater will also save money by bringing down your energy costs. The cold water is drawn into the heater when you turn on a tap, and a water flow sensor prompts heating mechanism to heat the water as it passes through the heater and give you hot water on demand.

How Does a Tankless Water Heater Work
Photo Credit: Inland Empire Plumbing Company

How Does a Tankless Water Heater Work?

There are two types of the tankless water heater, Electric and Gas depending on the energy sources used to heat the water in a tankless system. In the lower portion, I am going to describe to you how does an Electric and a Gas Tankless Water Heater Work.

How Does an Electric Tankless Water Heater Work?

How Does an Electric Tankless Water Heater Work?
Photo Credit: Edpaster

Electric Tankless Water Heaters help saves energy that produces a return on material costs, maintenance, and utility. They only need a cold water line and electrical hookup, and there is no need for costly valving/piping associated with conventional tank heaters.

The tankless electric heater component is composed of a series of ingeniously designed curls/coils that instantly heat water as it flows through the vessel. A different power switch automatically applies an electrical current to the curls when hot water is requested. The electrical current is not applied when water is not in use. The microprocessor can be present at the factory to maintain a consistent output temperature, even at varying flow rates of the unit.

The unit only functions once the user opens the control valve; thereby, there is no reserved heat which will be lost. You will only be paying for the warm substance which you consumed and not for the entire heating mechanism which runs on a 24/7 basis. Having these items in every household is a lot more convenient and economical. If you are searching for ways and means by which you can cut some costs on your bills, purchasing a tankless unit should be the number one on your list.

When someone opens the shower or any water outlet in any part of the house, this action will automatically be detected by a water-flow sensor. In turn, the tankless water heater will be set in motion. A chain of heating events will subsequently follow, and such will not stop until the user switches the faucet off. A regular shower only takes a few minutes, and this is the only time when the heater works as opposed to 24/7 continuous heating and reheating process. There is no overheating when you are using tankless heaters because once you are done using precious water, the sensor will no longer work and all the heating processes will cease.

How does a Gas Tankless Water Heater Work?

Tankless Water Heater Working
Photo Credit: Nicholsandphipps

In the middle of most recent tankless water warmers is an Electronic Control Unit (ECU). The ECU controls the majority of the elements of the warmer including ignition, modulation and temperature control and gas flow. It is additionally in charge of the well-being perspectives, with a fire sensor and programmed gas cut-off, in the case of an issue.

Getting Started: If you open a high temp water tap anyplace in your house, a stream sensor, associated with the ECU, recognizes the stream and the warming procedure starts. The ECU begins the stream of gas and triggers the igniter. The igniter sparkles until the fire sensor recognizes a fire. In case the gas neglects to light inside a few moments, the ECU close down the gas stream to keep any dangerous aggregation of gas.

Heating the Water: The gas burner applies warmth to the heat exchanger, through which the water passes. The course of the water is regularly a serpentine example, permitting the water to assimilate however much warmth as could reasonably be expected from the dividers of the heat exchanger.

As the temperature and flow rate of the incoming water can fluctuate, the ECU regulates the measure of gas that goes to the burner, turning it down or up, as required. This modulation of the burner intensity and gas is what keeps the water at a constant temperature. This usefulness depends on the contribution from a water temperature sensor on the way outside of the warmth exchanger.

To control the starting igniter, and light the gas, most consistent stream units are connected to your home’s power supply. However, there are a few units that utilization vitality made by the water moving through a little water turbine to give the ability to ignition. The turbine and battery-fueled units have a clear point of preference over the associated models since they will work notwithstanding amid a forced blackout.


As with most of the current energy efficient products today, the start-up costs tend to be expensive, but these are offset by the reduction in energy costs as you use the product. Using a tankless water heater uses much less energy than a traditional tank water heating system. You may need to do a few home renovations to install the system as electric models will need plugs and gas models will need proper ventilation. The systems should also be cleaned once a year and you may need to install filters depending on the quality of your water. Hope now you have no question in your mind about How Does a Tankless Water Heater Work.

If you have questions about the water heater, please contact us.