Water Level Controls in a Washing Machine Irrespective of brands, the primary function of the water level switch is to organize the quantity of water that goes into the tub. When the appropriate water level is attained the switch finishes a course to the machines’ timer and machine motor, and to the agitator control.
While the machine is on fill port, the switch contacts water control valves provided at water inlet, so that water fills in the washing machine. The timer motor runs only when the required water level is attained. Hence, there is no need to worry about running time being lost when the machine is in the filling process.
Float-type switches were used in earlier models of washing machines to set water level. Today, more efficient pressure-type water level switches are employed. A hose connects to the air bell placed below the outer tube of the machine. From there it links to the pressure switch at the back of the control panel. During the water filling procedure, an air pocket occurs inside the plastic hose.
When the water rises inside the tub, the air pressure inside the tube also increases. It goes on increasing till it makes the diaphragm inside the pressure switch activate switch contacts. Once this happens, the circuit to the valve is opened and the flow of water into the tub is stopped. When the draining process begins, the air pressure inside the hose begins to come down permitting the diaphragm of the pressure switch to reorganize the switch links.