At times you may feel your laundry is not coming out as clean as it used to be, then also you can doubt the possibility of an error in the heating element. Most probably the clothes might not be getting hot water and consequently they might be getting washed in cold water!
Controlling an electric water pump, to keep a container full of water. Just as in a washing machine, the depth of the water can be sensed from a hose connected to the base of the container.The advantage over a float switch is that the level is easily adjustable. Providing a low water level warning eg, the switch could be used to activate a buzzer or light if the liquid level in a tank drops below an adjustable point.