Why won't it stop washing?

Probably not one. Many different possibilities. Explain “stopped working”. As in no heat, won’t run, etc

E20 error code is the drain system, either an obstruction in the hoses or the motor doest have enough power ?

The out of balance is why it does not spin. You can manually stop the machine, and spin the basket. Then move the clothes until it is balanced. Then start it again on rinse & spin or drain & spin as appropriate. When you get tired of this, try below.

Or you can change the "Soil Level" to heavy or very heavy". This increases the water level and helps it balance the load.

Mine sudden stop after 15 to 20 minutes of running, I think my 3yr old spark plug but Im not sure...is this will happend.

The switch the tube connects to shuts the water off. Will it cut off on high medium or low level. You can try blowing on the tube to see if it works. It should cut off when you blow.

If your washer doesn't agitate, check these:Lid switchMotor couplerBeltsClutchDrive motorDrive pulleysTransmissionAgitator good-day !

You should give more information. If if agitates but doesn't spin or pump out, it is could be that something has plugged the hose to the pump (sock?) or something has jammed the pump (nail, pin) or the pump shaft is seized. Turn off the power if you are going to check the pump.

this could be a main control board problem.how ever i would check the drain pump for any kind of foregin object that may be causing the drain but to stop functioning.last resort bad drain pump

ok check how fast the water is draining,,might be a bit slow...onthejob