How to fix my AEG lavamat 62825?

Yesterday I did a wash and halfway through the washer started to beep and code E20 was displayed, we looked through the manual and did exactly what it told us, we did an emergency drain and cleaned out the pipe. We unplugged the washer also, then we plugged it back in and tried the wash again, the code was not showing and water was filling up and emptying when it should but the drum was only doing one rotation when it was washing but worked fine on spin and all water was drained out and the clothes were spun fine, so why is it only turning once then only every minute or so when it is on wash mode? Please help and hopefully I can mend it without paying someone!! Thank you