How Do Touchless Faucets Work?

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Modern and convenient, the touchless or automatic faucet is becoming a more popular choice for homeowners to install in their kitchens and bathrooms. When hands are placed under the spout of a touchless faucet the water easily streams out to provide a quick rinse. Don't be deceived by the touchless faucet's sleek, simple and user-friendly design. The fixture's complicated interior includes rubber controls to monitor the flow of water, an electromagnet and a power source to make the flow of water seem so effortless.



Keeping the sensor clean and the power source fresh will ensure that the touchless kitchen faucet stays in good working order.

Pros and Cons of Touchless Kitchen Faucets

Easy to use and relatively affordable, there are many benefits to choosing to install a touchless faucet in the kitchen, bathroom, wet bar or utility sink. The faucet handles and knobs are some of the most touched parts of the kitchen and bathroom. A touchless faucet cuts down on having to touch or interact with the faucet, which can cut down on the spread of bacteria as well as wear-and-tear on the fixture.


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  • By not having to touch the fixture, touchless faucets are free of bacteria usually found on handles and knobs of traditional sink water features.
  • The touchless feature reduces the amount of water that pours from the spout at one time. This is good for kitchen spaces where you may flip on the faucet and forget about the flow of water as you move around the room.
  • If your hands are full, you can still turn the faucet on by swiping in front of the sensor while holding stacks of dirty dishes.
  • The touchless faucet is an added value to a room and may increase the property value of the home.



  • The sensor needs to be cleaned regularly to keep it clear from soap and dirt build up.
  • The power source may need to be changed out with a new battery or cleaned, depending on the model.
  • The long spouts that typically come with a touchless faucet model contain all of the working parts of the touchless faucet. This can limit the design, but technology has come a long way and there are a wide variety of styles to choose from.


How Touchless Faucets Work

Touchless faucets are a technological marvel that can cut down on the transfer of germs and offer up a stream of clean water at the swipe of a hand. Touchless faucets allow you to rinse off bacteria from raw meat or sanitize your hands in any situation. They may seem like a simple technology in the kitchen or bathroom but a touchless faucet has inner workings that need some occasional TLC to keep them in good working order.


There are four key components that make the touchless or automatic faucet work on command. These are the sensor, power source, spout and, the most important part of the setup, the solenoid-controlled valve.

When the sensor detects your hands, the faucet turns on. Once the hands are removed, the faucet turns off. That is one part of the overall working wonder of the touchless faucet. To better understand how the faucet works, its best to know how each component works individually and then as a whole.



The Touchless Faucet Sensor

The sensor on a touchless faucet may seem magical but it is not able to detect actual motion. A sensor on a touchless faucet senses the presence of an object, whether it is the swipe of a hand or a stack of dirty dishes. The sensor tends to be located at the lip or base of the spout of a touchless faucet. This makes it easier to determine the presence of hands or an item under the spout without getting blocked by arms or large items within range of the sensor.


The sensors use a small infrared light that is mounted next to an infrared detector. The infrared light bounces off of your skin as it approaches the faucet and gets within a few inches. The signal turns on the faucet valve. There are also touchless faucet models that use an ultrasonic field sensor. This turns the faucet valve on when your hands or other items enter the small field around the faucet.


Sensor Tap Problems

There are pros and cons to having a touchless faucet. While they are easy to use, they can break down due to a sensor issue or power problem. Sensor tap problems are typical for touchless faucets. The sensor can become gunky with soap scum buildup, grease splatters or a film from the minerals that build up in areas with hard water.


If the Kohler touchless faucet is not working in the bathroom or kitchen, then there are a few quick and simple ways to check its efficiency before making major repairs or fully replacing the fixture, according to Kohler. Check the sensor first and make sure it is clean by wiping it down with rubbing alcohol. Replace the power source and tighten the fixture where needed to get the flow back.

Touchless Faucet Solenoid Valve

The sensor is attached and controls the solenoid-activated diaphragm valve located inside the faucet fixture. The solenoid pushes or pulls as an electromagnet, depending on the electric polarity. A rubber disc controls the water flow in a diaphragm valve.



The diaphragm valve is typically held shut until the sensor signals that hands or other large objects have been detected. The solenoid then pulls the valve open to allow water to flow from the spout. When the objects or hands are no longer detected in front of the sensor, the valve is then pushed down and closed.

Some touchless faucet models can provide hot or cold water, depending on how the fixture is set. However, most touchless faucets simply spout warm water unless otherwise directed.

Touchless Faucet Power Sources

There are a few ways in which a touchless faucet gets its power. Depending on the mode, a low-voltage current from an AC transformer can provide power to allow the water to flow, or power may come from a dry-cell battery inserted in the back or neck of the fixture.

Electricity is needed to power the sensor, control electronics and operate the water valve. A battery-powered faucet uses a latching solenoid valve. This stays in the open position until a flow of power pushes them back to the shut position.

Transformer-powered faucets have a continuous electric current that holds the solenoid valve open in order for the water to flow. This can get damaged over time and need repairs. If the water is not flowing as well as it has in the past, you may want to check the power source.




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