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Replacement parts for FRIGIDAIRE GLWS1339ES0 Frigidaire/washer | AppliancePartsPros.com

Water level switch is Item F5 (5) in Section 4.

Odds are you accidentally unplugged the hose either at the switch or at the tub end. Probably the switch as you did not say the un itwas leakink water under the unit.

Below is my standard reply for water valve problems:

This switch is actually a pressure switch. It has a tube that runs down to the bottom of the tub, as water fills the tub, air is trapped in the tube. As the water rises, the air pressure in the tube increases until it reaches the switch's set point then the switch activates turning off the water and starting the agitate.

Possible problems.
1. Gunk blocking water from entering the tube. Remove the tube at the switch and blow into it to clear the plug.
2. Cracks or holes in the tube allowing the air to escape. Inspect the tube.
In your case it may have been pulled off the switch.Also check that it is tight on the switch, if not, cut off half an inch and re-seat it.
3. The switch is toast. Get a piece of tubing with the same internal diameter and attach this to the switch. Start a fill, then blow into the tube. You should be able to stop the water flow without blowing very hard.
If you cannot stop it the switch is toast.

Note: That you may be able to stop it by blowing into then tubing and it may still be no good as it needs too much pressure to activate the switch.
So if the tubing is OK replace the switch.