To test your washing machine’s pressure sensor safely, unplug the appliance, locate the sensor or control board, and use a multimeter to check voltage changes as the tub fills. Changing voltage confirms communication between the sensor and the control board is working.
Testing the washer’s pressure sensor helps determine if water-level errors come from the sensor itself, the control board, or the connected air pressure tube. With just a screwdriver and multimeter, most DIYers can diagnose the issue and decide whether a replacement pressure sensor or control board is needed.
What does a washing machine pressure sensor do?
The pressure sensor tells the control board when the tub has enough water for each cycle. It measures air pressure through a small tube attached to the tub, signaling the board to open or close the water inlet valve as needed.
In most modern washers, the electronic pressure sensor regulates water usage for efficient washing and rinsing. Some models have a stand-alone sensor mounted under the top panel; others integrate the sensor directly into the control board. Either type ensures accurate water levels during fill and rinse cycles.
Typical top-load washers use 8-18 gallons per load, while front-load models use only 2-5 gallons. The pressure sensor continuously adjusts water flow to maintain these efficient levels.
How does the sensor send signals to the control board?
As the tub fills, air pressure builds inside the attached tube. When the pressure reaches a preset level, the sensor sends a signal to the control board to stop filling and begin agitation. During draining, it resets for the next rinse.
One end of the air tube connects to the tub and the other to the sensor or board. This simple air-pressure change allows precise electronic control without direct contact with the water. The process repeats for each wash and rinse stage, maintaining correct water volume.
How can a faulty pressure sensor affect my washer?
A bad pressure sensor can cause overfilling, underfilling, or mid-cycle stoppage. If the sensor or air tube fails to signal properly, the washer may overflow, stop unexpectedly, or never start filling at all.
The entire fill and rinse system depends on the sensor and the air tube working together. A torn or blocked tube prevents accurate pressure readings, while a defective sensor can miscommunicate with the control board. Replacing a damaged air pressure tube or sensor typically resolves these water-level problems.
How do I use a multimeter to test a washer pressure sensor?
To test a washer’s pressure sensor, unplug the machine, access the sensor or control board, and use a multimeter to check for voltage changes as the tub fills. Consistent voltage shifts mean the sensor is responding; no change signals failure.
Before testing, inspect the air tube for kinks or tears and replace it if necessary. For most models, the sensor sits under the main top or behind the console. If it’s part of the control board, remove the housing carefully after unplugging the washer.
Once you reach the sensor, plug the washer back in for testing, keeping clear of live components. Determine whether your model uses AC or DC voltage and set your multimeter accordingly. Use the wiring diagram to find the input and output terminals.
Start a fill cycle and observe the readings. As water enters, voltage should rise or fall depending on design. If no voltage appears at the sensor, the control board may be at fault. If voltage doesn’t change as water fills, the pressure sensor itself is likely defective.
What should I do if the pressure sensor fails the test?
If the voltage reading stays flat, replace the faulty sensor with a genuine OEM part. On some washers, the sensor is part of the control board, so the entire board must be replaced. Either fix will restore proper fill and rinse control.
Installing an OEM pressure sensor ensures accurate readings and longer life. Once installed, rerun a short wash to verify that the tub fills correctly and no overflow or fill errors occur.
How can I prevent pressure sensor problems in the future?
Keeping your washer clean and level protects the pressure sensor. Regularly check the air tube for moisture, detergent buildup, or debris that could block airflow. Avoid over-sudsing, which can send soap residue into the sensor line.
Once a month, run an empty hot-water cycle with a washer cleaner to remove detergent film and prevent residue from reaching the sensor port. These small habits help maintain stable water-level readings and prevent false error codes.
If you experience inconsistent filling again, check related components such as the water inlet valve or drain pump before replacing the sensor a second time.
Where can I buy the right parts to fix my washer’s pressure sensor problem?
Find the correct part by entering your washer’s full model number in the Repair Clinic search bar. You’ll see only compatible OEM pressure sensors, control boards, and air pressure tubes for your appliance.
Repair Clinic stocks genuine manufacturer components for major brands including Whirlpool, LG, Samsung, Maytag, GE, Kenmore, Bosch, and Frigidaire. Each product page includes installation videos and diagrams to guide your repair.
Shop replacement sensors, valves, and control boards at Repair Clinic today and restore your washer’s water-level accuracy.