How to Check a Washer Water Level Pressure Switch With a Multimeter
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The person typing how to check a washer water level pressure switch with a multimeter wants to know whether the switch that tells the washer how full the tub is has failed. A multimeter can show whether the switch contacts open and close as expected, with the washer unplugged and the water supply off. It cannot tell you which terminals to test on your model, because the sources we opened do not cover a specific washer’s wiring. Use the wiring diagram on your model for the terminal pairs. Each step below names the check, the setting and the result, so the reader can stop at the first clear answer.
Quick answer
- Unplug the washer, shut off the water supply, and disconnect the switch harness.
- Set the meter to continuity. Test the terminal pairs in the wiring diagram, one pair at a time.
- A pressure switch is a set of contacts that opens or closes at a set pressure. Expect one state when the tub is empty and the other when it is full.
- Check the air hose for kinks or water before you blame the switch.
- The opened sources do not state the expected reading for any washer model. Confirm the readings against the manual.
Safety first: a washer is a mains appliance, and water is nearby. Unplug it and shut off the water supply before you open the top or the back panel. If the switch is reached only by removing parts you are not comfortable handling, call a qualified appliance technician.
How a pressure switch works
A pressure switch is a set of contacts that changes state when air pressure in a tube reaches a set level. In a washer, the water level rises, compresses the air in a hose connected to the switch, and the switch changes state. The control board reads that change as the water level. Fluke’s manual approach to pressure switch testing describes the same idea: the switch has a common terminal and a normally open terminal, and it reads open at rest and closes when the set pressure is reached.
That means a test has two parts. First, check the contacts with the switch unpressurised. Second, check whether the contacts change when the air pressure changes. The second part is harder at home, and this guide focuses on the first.
Tools you need
- A digital multimeter with a continuity mode and an ohms mode.
- The washer’s wiring diagram, which identifies the switch terminals for your model.
- Insulated screwdrivers, and a phone camera to photograph the harness.
Fluke’s continuity guide explains that the meter emits a beep when a complete path is detected, and that an open switch will not beep. Fluke’s resistance guide says the display should show OL in resistance mode with no leads connected.
Step-by-step check
Step 1: Unplug and shut off the water
Unplug the washer and close the water supply valves. Fluke’s guidance is to de-energize the circuit before connecting the leads.
Step 2: Find the switch and the wiring diagram
Locate the switch on the top or the back of the washer. Find its terminal layout in the wiring diagram for your exact model. Photograph the harness before you unplug it. Terminal labels differ between models, so do not guess the pair from a different washer.
Step 3: Disconnect the switch
Unplug the switch harness from the switch, so the meter reads the switch alone and not the control board. Keep the air hose connected for now, because you will check it in step 6.
Step 4: Check the meter
Set the meter to continuity. Touch the probes together and confirm the beep.
Step 5: Test the terminal pairs
Test the common terminal against the normally open terminal, and the other pair in the diagram, one at a time. Fluke’s manual approach describes the common and normally open terminals as the pair to measure. With the tub empty and the switch at rest, the normally open pair should read as an open circuit, which means no beep. A switch that is closed at rest can mean the control board sees a full tub, and a washer may refuse to fill.
If your model’s diagram shows another pair that should be closed at rest, test that pair too. Record each pair’s beep or no-beep result.
Step 6: Check the air hose before blaming the switch
Inspect the air hose from the switch to the tub for kinks, cracks, or water inside it. A blocked or leaking hose can mimic a bad switch, because the switch never sees the pressure change. Fix or replace a damaged hose before you replace the switch.
Step 7: Read the resistance if your model’s diagram calls for it
Some diagrams give a resistance value for a terminal pair rather than a simple open or closed state. In that case, switch to ohms with autorange on and read the pair. Fluke’s resistance guide notes that the meter automatically adjusts to the best range in autorange mode. The sources we opened do not give an expected value for any washer switch, so compare with the diagram.
Reading the results
| What you see | What it usually means | Next step |
|---|---|---|
| Normally open pair reads open at rest, as the diagram expects | Contacts are behaving as expected at rest | Check the hose and the control side next |
| Normally open pair beeps at rest | Contacts are closed at rest, which may be a fault | Confirm the diagram, check the hose, then consider the switch |
| Diagram pair shows no beep when it should close | Possible open contact | Check the hose for a blockage first, then the switch |
| Beep only when the harness moves | Loose connector | Reseat or repair the connector before replacing the switch |
If the switch tests as expected
A switch that tests as expected at rest does not prove it responds to water level. The hose, the water inlet valve, and the control board can all cause a fill problem. The sources we opened do not cover washer control boards or inlet valves, so check the model’s manual for those tests.
Mistakes to avoid
- Testing with the washer plugged in. Fluke’s guidance is to de-energize the circuit first.
- Guessing the terminal pair. Use the wiring diagram for your model.
- Replacing the switch before checking the air hose.
- Using a terminal map from a different washer brand or model.
How this guide was built
This guide uses three opened Fluke Learn sources: the manual approach to pressure switch testing, the continuity guide and the resistance guide. The pressure switch page describes a general switch test with a calibrator, not a washer. Washer-specific terminals and values come from the model’s diagram. For basic meter use, see How to Test a Multimeter and How to Set a Multimeter to Ohms.
How we chose
The steps are ordered the way a reader works: power and safety first, then isolating the part, then reading the result. The sources were limited to Fluke Learn pages opened on 2026-10-27. Parts-retailer and repair-forum pages that search returned were not used as sources. Each step names only what the opened source states, and any value that the opened sources do not give is marked as not verified.
What we could not verify
- The terminal layout and expected states for any specific washer model.
- The pressure settings at which a washer switch changes state.
- The behaviour of the control board and the inlet valve.
FAQ
Can a multimeter test a washer pressure switch?
Yes, for a basic check of whether the contacts open and close as the wiring diagram expects, with the power off.
The washer keeps filling or will not fill. Is the switch the cause?
It can be, but a kinked hose, a blocked air path, or a control fault can cause the same symptom. Check the hose first, and use the model’s manual for the control tests.
Which terminals should I test?
Use the wiring diagram for your exact model. Terminal labels and colours differ between washers.
What does OL mean on the meter?
Fluke describes OL as an infinite reading, which means no complete path. For a normally open pair at rest, that is the expected result.
Can I test the switch with the washer running?
No. Fluke’s guidance is to de-energize the circuit before a continuity or resistance test.
Bottom line
Unplug the washer, shut off the water, and test the pressure switch pairs named in your wiring diagram. Check the air hose before you blame the switch, and confirm any reading against the manual before you buy a part.
Sources
- Fluke, “Manual Approach to Pressure Switch Testing,” opened 2026-10-27: https://www.fluke.com/en-us/learn/blog/calibration/manual-approach-pressure-switch-testing
- Fluke, “How to Test for Continuity,” opened 2026-10-27: https://www.fluke.com/en-us/learn/blog/digital-multimeters/how-to-test-for-continuity
- Fluke, “How to Measure Resistance with a Digital Multimeter,” opened 2026-10-27: https://www.fluke.com/en-us/learn/blog/digital-multimeters/how-to-measure-resistance
