Why do you need a pressure switch in a washing machine?

Why do you need a pressure switch in a washing machine? Water enters and is removed from the washing machine using a pump and fill valve. All washing operations are controlled by the “brain” in the form of a module that receives data and issues adequate commands. However, without a pressure switch, all the machine’s efforts are in vain.

What is this part for?

It is the pressure switch in the washing machine that is needed to control the volume of liquid in the drum. The device determines the amount of water based on the force of its pressure. Without its correct operation, the control module does not turn on the water, and if it does, it pumps it out - just in case. Therefore, without a water level sensor, the “washing machine” is powerless.

This relay, round or (less often) rectangular in shape, is equipped with a hose-tube and wires. The design of the device depends on the capabilities of the washing machine, the number of its functions and modes. Therefore, each model of washing machine has its own pressure switch. There are mechanical/pneumatic and electronic relays that have an oscillating circuit. The latter differ in the rigidity of the diaphragm and the stroke of the core. how does a pressure switch work?

The pressure switch is made from high-quality plastic and, depending on the type of machine, is located in the following places:

directly under the housing cover - in classic machines that have a loading hatch on the front wall;
under the drum - in “washing machines” with vertical loading of laundry;
near the rear wall, below the tank - in machines with a plastic drum.

Description of the element's operation

To understand the principle of operation of a pressure switch, you need to know about its structure. A typical water level sensor consists of the following elements:

magnetic/ferrite core;
membranes/diaphragms;
sensor in which the diaphragm is located;
springs;
adjusting screw;
inductive coil, board and capacitors. The function of these components is to ensure the functionality of the relay parts;
contacts;
housings;
compression chamber. It is located at the base of the hose-tube connecting the camera to the sensor. Its clogging is one of the reasons for malfunctions in the washing machine.

The action of the pressure switch is based on the pressure of the water column on the membrane. Pressure occurs when liquid enters the tank through a compression chamber connected to a tube. The membrane, in turn, under fluid pressure, moves the core that closes the contacts. When a certain volume of water is reached, one of the switches is activated (a relay signals this to the control module).

When draining waste water, the pressure in the hose-tube decreases. The core returns to its original position and the relay opens. A working pressure switch accurately responds to all indicators of liquid pressure, sending signals to the control module of the washing machine. The volume of liquid poured, determined for each washing operation, depends on the reliability of its impulses. Only the machine manufacturer can accurately calibrate the sensors. It is not recommended to adjust the pressure switch yourself.