Water Level Switch Function

The water level switch sends power from the timer control to the water inlet valve and the temperature switch each time the tub needs to be filled during a wash cycle. As the tub fills, the switch cuts off the water flow when the water level inside the tub correlates with the setting for a large, regular, or small load. The switch then signals the motor to begin agitating.

Identifying the Water Level Switch

The water level switch is found in different places on different machines—in many cases, it’s inside the control console, but check your owner’s manual to find out where yours is. You can distinguish the water level switch from other round switches inside the washer cabinet by its rubber tube that runs from the switch down the side of the tub. As the washer fills, water enters the tube from the bottom and increases pressure in the airspace within the tube. When the pressure reaches the critical point, the switch shuts off water flow to the tub.

Inspecting the Tube

Inspect the water level tube and, if necessary, clear any blockage. Always unplug the machine from the wall outlet before doing any inspection or working on your washing machine.

Testing the Switch

Next, test the switch for electrical failure. To test the switch for continuity, use a multimeter (also called a volt-ohm meter) set at OHMS x 1.

Find the wires leading to the terminals of the switch. Disconnect them from the terminals: This usually means disengaging a wire plug, but if the wires are connected to the terminals by other means, label them for position before disconnecting them.The water level switch has three terminals. Test them for continuity in pairs. First, touch the meter probes to terminals 1 and 2. Note the reading, which should be either ∞ (infinity, which means no continuity) or some value close to 0.0 (continuity).Touch the probes to terminals 1 and 3, and note the reading (∞ or approximately 0.0).Touch the probes to terminals 2 and 3, and note the reading.Analyze the results of the continuity tests: Two of the pairs should have no continuity, and one should have continuity. If you get a different result, the switch is bad and needs to be replaced.Reconnect the tube to the switch in preparation for the second round of continuity testing, and leave the other end of the tube disconnected.Blow gently into the tube while retesting the terminals for continuity in pairs, using the same sequence as in the first round of testing. You should hear the switch click when you blow into the tube. Maintain the air pressure by pinching the tube closed as you test the terminals, and note the results.Analyze the results of the second round of testing, and compare them to those of the first round. The pairs that showed no continuity in the first round should show continuity in the second round (with pressure in the tube). The pair that showed continuity in the first round should show no continuity in the second. Results other than these mean that the switch is bad and needs to be replaced.If the continuity testing does not indicate an electrical problem in the switch, reconnect the clean, straightened pressure tube to the nipple at the bottom of the tub and run the machine through a cycle to see whether the problem has been corrected.