What Is Automatic Toilet Flusher And How Does It Work

Concealed automatic toilet flush solution


Nowadays, people care more about hygienic and cleanness, especially during pandemic outbreak times. Think about when you go to a public restroom in a shopping mall, you need to press the button or turn on the faucet every time. After so many people using it, how dirty and germs will pass to you. Will you worry about it? Here we will offer a solution for you.

We also have nine tips for choosing a toilet that can help you to choose the correct toilet. Please view our blog here.

What is automatic toilet flushers?

Automatic toilet flusher uses active infrared sensor technology which uses the emission and reception of infrared beams to detect the presence and movement of objects or people in their field of detection. When the sensor detected the body, it is ready to work. When people leave, it flushes water automatically. Some of our models also come with water save mode: 4s per flush if usage time less than 1min and 9s per flush if usage time more than 1 min.

Four key parts of touchless toilet flusher

Before introduce how the automatic toilets work, we would like to introduce the key parts firstly. Then you will know how it works easily.


toilet flush valve KEG K313
Motion Sensor Auto Toilet Flusher KEG-3500D

As a key part of an auto toilet flush, the sensor is like an eye to detect the movement of objects or people. Its job is to inform the valve when to start or stop the flow based on the presence and/or movement of objects or people. There are two infrared LEDs inside the sensor, one LED emits the infrared beams and one LED receives the infrared beams.

Normally the sensor eye is placed on the metal faceplate. Mostly the plate is made of stainless steel, some may using cheaper plastic material.

For some items, the sensor is integrated inside the flush valve. You can see it obviously from the photo on the left.

2. Solenoid valve

6V Brass Solenoid Valve For Automatic Toilet Flusher KEG-F31

As a key part of the auto flush toilet or flushometer, the valve is like a switch to open and close water flow. When it receives a signal from the sensor, it opens or closes the water flow.

The positive or negative signals from the sensor control the solenoid valve. The polarity of the signal determines if the solenoid will either engage a pull or push action. The valves control the water flow by using a rubber-like disc. When there is no signal, the valve is closed, meaning no water flow through the valve. The presence of body movement will send a positive signal to the solenoid causing it to pull the valve open for water to flow.


DC battery box for touchless faucet
power ac adapter

As a key spare part, the power source is also very important to supply the electronic parts with power. Normally there are three types, DC battery, AC power supply, and combined AC/DC type.

DC battery operated, normally 6V 4xAA or 3V 2XAA alkaline batteries. Battery replacement is easy, just open the battery box cover and put the new alkaline batteries into the box.

AC adapter, one side with a power plug and one side with waterproof connector connect with the sensor or control box, there is a power transformer inside the adapter. The input can be 110v-380v and output 6V-9V. The ac adapter is not expensive and can buy it separately.

The diagramm is controlled by microchip and allows little power.Both the sensor and valve works with low power energy.

Notice: please take care of the battery polarity.


waterproof connector cable C02C-2

As a key part, the waterproof connector cables connect every subpart, like a bridge to connect the sensor with a solenoid valve and power battery or AC Adapter. Also considering the humidity of the bathroom and toilet environment, it has high requirements for the electronic control system and every electronic component. In order to solve the problem, KEGE develops and designs anti-plug water-proof connector cables. It effectively increases the stability and reliability of the whole control system and the life of the touchless faucetsautomatic urinal flusherautomatic toilet flusher, and so on. What’s more, the waterproof grade of the cable reaches ip67.

How do automatic flush toilets work?

After introducing these four key parts, I will let you know toilet sensor flush how it works.

  1. The infrared sensor has infrared LEDs (light-emitting diodes) and detectors like those used on the TV remote controls. The sensor detects when infrared light is reflected by the user. 
  2. After the detection, the sensor will give a pulse signal to the solenoid valve to let it open.
  3. The whole program is designed and controlled by a microchip. Normal Mode flush time 9s; Water saving Mode: usage time less than 1min: 4s/flush while using time more than 1min: 9s/flush.

For more details, please also read what is an IR sensor and how does a solenoid valve work.

Suggest automatic toilet flushers:

For the best automatic toilet flushers, please check our blog here for your reference. Below we list some common and cheap models.

Automatic toilet flush valve

Motion Sensor Auto Toilet Flusher KEG-3300D
automatic toilet flusher KEG-3600D

Concealed automatic toilet flusher

Automatic Toilet Flusher KEG-GB-8300ADM
Auto Toilet Flusher KEG-3166AD
automatic toilet flusher KEG-312

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