How to Replace LG Washing Machine Pressure Switch

How LG reads the water level#

The pressure switch never touches water. A thin air tube runs from the bottom of the tub up to the switch; as the tub fills, rising water compresses the air in the tube, and the switch registers set pressure points that tell the board how full it is. When the switch fails — or the tube kinks, cracks, or clogs — LG throws PE (Pressure Error), and the machine can overfill (a flood risk), underfill, or refuse to leave the fill phase.

Tools and safety#

• Tools: Phillips #2 screwdriver, small pliers for the hose clamp
• Time: 15-25 minutes · Difficulty: beginner
• Safety: unplug the machine; you are not opening any water lines for this one.

Step-by-step#

1. Lift the top panel#

Unplug the washer, remove the two Phillips screws at the rear of the top panel, slide it back and lift it off. The pressure switch is a disc about two inches across on the upper-right or upper-left of the cabinet frame, with a wiring plug and a thin rubber hose.

2. Check the air tube before anything else#

Follow the tube from the switch down to the tub. A kinked, cracked, or unplugged tube causes PE all on its own — reseat or replace it. Pull it off and blow through it; if it is blocked with sediment or mold, clear or replace it. This step is free and fixes many PE codes.

3. Remove the old switch#

Unplug the electrical connector (press the tab, pull straight), work the air tube off the switch nipple (squeeze the little clamp if fitted), and remove the one or two mounting screws or release the clip. The switch lifts out.

4. Fit the new switch#

Mount the new switch in the same spot, press the air tube firmly back onto the nipple so it is airtight, and click the electrical connector home. Make sure the tube runs to the tub without a kink.

5. Test it#

Plug in and run a Normal cycle, watching through the door — the water should stop at about halfway up the drum window on a standard load, with no PE code. If it overfills, cut power at once and check the air tube: an open tube means the switch never senses pressure and the machine fills without limit.

6. Calibrate if your model needs it#

Some LG models want a calibration run after a switch swap — commonly by holding Spin Speed + Soil Level for about three seconds with the machine empty and the door closed. Check your service manual for the exact combination.

Troubleshooting#

• PE stays with a new switch: the tube is still blocked or has come off the tub end — trace it end to end.
• Overfills then shows PE: the switch is not sensing — confirm the tube is tight on the nipple with no holes.
• Level jumps between cycles: water sitting in the tube skews the reading — blow it clear and reconnect.

When to call a professional#

Call a tech if it overfills and you cannot find why (a flood risk worth stopping for), or if PE shows up alongside other codes, which points at the control board rather than the switch.

Clear the tube, save the switch#

Most PE calls are the tube, not the switch, so it is worth being thorough here before spending on a part. Detach the tube at both ends, flush it under a tap, and let it dry — a plug of grey sludge or a pinhole crack is all it takes to scramble the reading. Route the dried tube so it rises steadily from the tub to the switch with no low dip; a sag collects water that sits in the line and throws the level off from one cycle to the next.